Resource Conservation Technologies in the Context of Climate Change Edited by Dibyendu Chatterjee Christy B.K. Sangma Z. James Kikon Sanjay Kumar Ray Pulakabha Chowdhury Lahar Jyoti Bordoloi Bidyut C. Deka
ICAR Research Complex for NEH Region Nagaland Centre, Jharnapani Medziphema, Nagaland 797 106
All rights reserved ISBN: Published February, 2015
Edited by Dibyendu Chatterjee1, Christy B.K. Sangma2, Z. James Kikon3, Sanjay Kumar Ray4, Pulakabha Chowdhury5, Lahar Jyoti Bordoloi6, Bidyut C. Deka7 1. 2. 3. 4. 5.
Scientist, Soil Science, ICAR Nagaland Centre Scientist, Soil Science, ICAR Nagaland Centre SMS, Soil Science, KVK Dimapur, ICAR Nagaland Centre SMS, Soil Science, KVK Wokha, ICAR Nagaland Centre SMS, Soil and Water Conservation Engineering, KVK Longleng, ICAR Nagaland Centre 6. Assistant Chief Technical Officer, T-7-8, ICAR Nagaland Centre 7. Joint Director, ICAR Nagaland Centre
Published by: Joint Director, ICAR Research Complex for NEH Region, Nagaland Centre, Jharnapani, Medziphema-797 106, Nagaland
Copies available at: © ICAR Research Complex for NEH Region, Nagaland Centre, Jharnapani, Medziphema797 106, Nagaland
Disclaimer This book is a first site general recommendation exclusively for extension purpose. Some contents and photos are taken from difference sources to make more elaborative for the village level extension functionaries for their easy understanding and only meant for welfare of farmers. Source person are well acknowledged and do not violate any copyright rules. If any issue arises, editors must be prior informed before legal action.
Foreword North east India is constituted by eight states having hills and dales topography. Due to its peculiar photographic make up and ineffective northeast monsoon, the climate of different parts has assumed regional characters. Landslides and monsoon floods are very common. Most of the annual rainfall occurs during the summer season, resulting in excess soil moisture during monsoon season and deficit soil moisture during the rest of the year. Hence, climate has played a significant role in the economic development of North Eastern India. But, the climate of the region is facing some changes in respect of erratic rainfall patterns and increasing temperature in the recent years. Therefore, it is essential to have an assessment of impacts of climate change on agriculture as well as livestock sector. Realizing the importance of climate change impacts and need of climate resilient resource conservation technologies, the whole NICRA team has taken an initiative to publish a book cum training manual on climate change resilient resource conservation technology which could be a for reference book for taking future endeavour in the respective field. I am happy that the ICAR Research Complex for NEH Region, Jharnapani, Nagaland Centre is going to publish a Book cum Training Manual on Climate resilient resource conservation technology under NICRA project. I am thankful to the whole team of NICRA Project, ICAR Research Complex, Nagaland Centre for taking pain in publishing such type of relevant issues. I am sure that the researcher, planner and extensions will find this book quite useful.
Place: Jharnapani February, 2015
Joint Director
Pref ace Nowadays, one of the emerging challenges faced by the world’s agricultural sectors is a changing climate. Climate change alters the basics of productive ecosystems, impacts on natural resources and affects food security. From a socio-economic perspective, small and marginal farmers, forest dwellers, fishers and groups least able to adapt, will be the most affected by climate change. Moreover, climate change cannot be effectively addressed without addressing emissions from the agricultural sectors, estimate to contribute some one-third of all greenhouse gases. As a result, there is a growing need to ensure that climate change considerations are mainstreamed into agricultural investment projects and programs with particular interest on the linkages with and among food security and rural livelihoods (FAO, 2012). During the next decades, people will face changes in climate patterns that will contribute to severe water shortages or flooding, and rising temperatures that will cause shifts in crop growing seasons. This will increase food shortages and distribution of disease vectors, putting populations at greater health and life risks. The predicted temperature rise of 1 to 2.5° C by 2030 will have serious effects, especially in terms of reduced crop yield. However, there are lots of uncertainties about the assessment of impact, adaptation and mitigation of climate change in agriculture. It is largely because the methodology followed for such assessments is not standardized and sometimes it is inaccurate and imprecise. Researchers follow different methodologies and arrive at contrasting results making it difficult to reach a logical conclusion and develop policy actions. There is a need to develop and apply a standard methodology for various studies related to climate change and agriculture. This may be the first book cum training manual from the ICAR Research Complex for NEH Region, Jharnapani, Nagaland Centre to comprehensively present the recent, resource conservation technologies to address the climate resilient agriculture and analyzing the vulnerabilities and mitigation options. The book describes the methodology in a simple and lucid way so that a researcher can adopt it in laboratory and field studies. Individual chapters are focused to subjects such as Climate change, Conservation agriculture and its significance in climate change scenario, Soil health management in context of climate change, Elementary techniques: diagnosis of disorders, sampling and analysis of soil/plant under changing climate scenario, Meteorological variations, Abiotic stresses, Effect of climate change on rice in India, Mulching, Nutrient recycling, Water budgeting, Effect of climate change on important animal/birds, Effect of climate change on important animal/birds, Effect of climate change on horticultural crops, Vulnerable agro-ecosystem, Vulnerable climatic conditions for occurrence of diseases in crops, Disease/disease management, Climate resilient important Crop varieties and Contingency planning. Therefore, the authors hope that this book cum training manual will help a planner, researcher and extension agent to increase its awareness and understanding of the basics of climate change adaptation and mitigation in the agricultural sectors; have a basic knowledge on methods for climate change adaptation and mitigation in agricultural sectors and different climate resilient resource conservation technologies. Place: Jharnapani February, 2015
Editors
Contents Sl. Title Page No. No. 1. Climate change and agriculture: A multidimensional perspective 1 - Dibyendu Chatterjee and Saurav Saha 2. Meteorological variations in the hill climate of Nagaland 9 - P. Chowdhury, Tasvina R. Borah, Dibyendu Chatterjee, Imtisenla Walling and Bidyut C. Deka 3. Resource conservation options in the context of climate change 12 - D.J. Rajkhowa 4. Soil health management in the context of climate change 18 - S. Hazarika 5. Soil testing for optimization of agricultural production in the climate 23 change scenario - Jurisandhya Barik Bordoloi 6. Abiotic stresses: Its influence on crops and possible mitigation 28 strategies - Christy B.K. Sangma 7. Effect of climate change on rice production in India with special 32 reference to North-East Hill Region - Ch. Roben Singh 36 8. Soil and water conservation through mulching - Z. James Kikon 9. Nutrients recycling through waste management-A key for climate 40 proofing Agriculture - Lahar Jyoti Bordoloi 10. Water budgeting in hill farming of North Eastern Region of India 46 - P. Chowdhury, Dibyendu Chatterjee and Bidyut C. Deka 11. Livestock production in a changing climate: Impacts and mitigation 52 - Manas Kumar Patra and Yhuntilo Kent 12. Impact of climate change in horticulture 57 - A. Thirugnanavel 13. Climate resilient aquaculture 61 - S.K. Das 64 14. Managing vulnerable agro-ecosystem through horticulture based farming - Bidyut C. Deka, Dibyendu Chatterjee and A. Thirugnanavel
15. Climate change and pest population dynamics: Strategies for their management - D.M. Firake, G.T. Behere and N.S. Azad Thakur 16. Effect of climate change on plant disease scenario - Rajesha G. and Tasvina R. Borah 17. Horticultural crop diseases as influenced by excess or deficit moisture - Tasvina R. Borah 18. Important varieties in the context of climate change - Kolom Rabi 19. Contingency planning in climate change scenario - Sanjay Kumar Ray 20. Contributors
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Climate change and agriculture: A multidimensional perspective Dibyendu Chatterjee and Saurav Saha Introduction Climate is the synthesis of the site specific weather conditions, characterized by the long-term statistics of different surface weather variables, recorded in the specified area (World Meteorological Organization, 1992). Agriculture is essentially a man-made adjunct to natural ecosystems that entirely depends on different weather variables. Climate science has made significant progress, evaluating the direct and indirect impact of climate on agricultural productivity. Our surplus crop production in the post ‘Green Revolution’ era, are fulfilling the food demand of ever increasing world population that surpassed the 7 billion mark by 2011. With the projected growth rate, the world's population is expected to reach 10 billion by 2050. Consequently, the demand for food crops will grow faster (Anonymous, 2015a). As the population expands, our total crop production must increase accordingly to achieve the food security. In addition, recently the urgent need has been felt to maintain the sustainability of our present agricultural production system through ‘Evergreen Revolution’.
Climate change: A recent perspective Natural and anthropogenic greenhouse gases (GHGs) act as drivers of climate change by altering the earth’s energy budget. The largest contributors to climate change and surface warming are atmospheric CO2 followed by CH4, halo-carbons, N2O etc. (IPCC, 2013). The prospective climate change is global warming, mostly induced by the radiative forcing of increasing active GHG concentration in the atmosphere. Presently, there is evidence that our planet have warmed about 0.5°C over the past century. Rapid industrialization in post industrial revolution era is the main responsible factor for this rise in the atmospheric GHG concentration. Being the most abundant GHG, atmospheric CO2 is increasing because of extensive fossil fuel combustion. Our agricultural production system also accounts ~10–12% of the total global anthropogenic emissions of GHGs (IPCC, 2007), which are coming under increasing scrutiny in recent days. The increased agricultural activities and organic waste management are presumed to be contributing to the buildup of CH4 and N2O in the atmosphere. Relative contributions of different GHGs to anthropogenic warming are listed in Table 1. Table 1: Relative contribution of GHGs (%) to anthropogenic greenhouse effect (EIA, 2008) Greenhouse gases % Contribution Energy-related carbon dioxide 81.3 Methane 10.5 Nitrous oxide 4.3 Carbon dioxide from other sources 1.5 Hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride 2.5 (SF6) Ice core analysis confirmed the present increase in atmospheric CO2 concentration, from ~280 ppm in the pre-industrial era to 399 ppm in 2014 (Saha et al., 2015), with an average increasing rate of 2.06 ppm year-1 during the last 14 years (Fig. 1), and is expected to reach about 570 ppm by 2050. As a consequence, the average global air temperature has already increased by 0.7 °C during last 100 years. The decade 1990–2000 was the warmest in the last 300 years and was 0.5 °C warmer than the mean temperature of 1961–1990. If there is no mitigation of GHG emissions over the next century, global mean annual temperature is expected to rise by 1.8–6.4°C by 2100 AD depending on the emissions scenario in the next few decades (IPCC, 2007). Globally, the projected change in mean precipitation showed an erratic trend with more regional influence. Global warming would increase rainfall in some areas, which would lead to an increase in atmospheric humidity and the 1
duration of the wet season (Kaur and Rajni, 2012). The annual greenhouse gas bulletin from the WMO showed that in 2013 concentrations of CO2 in the atmosphere were 142% of what they were before the Industrial Revolution. Other potent GHGs have also risen significantly, with concentrations of methane now 253% and nitrous oxide 121% of pre-industrial levels.
Fig. 1: Average rate of increasing atm. CO2 (ppm year-1) in global climate system (1959-2014) Source: NOAA, 2014 The warming trend in India over the past 100 years has shown an increase in mean temperature by 0.6°C indicating significant warming due to climate change (Anonymous, 2015b). This warming trend is comparable to increases in global mean temperature in the past 100 years. It is projected that rainfall patterns in India would change with the western and central areas witnessing as many as 15 more dry days each year, whereas the northern and northwestern areas could have 5 to 10 more days of rainfall annually. Thus, dry areas are expected to get drier and wet areas wetter. Crop simulation studies predicted the significant negative impacts with medium-term (2010-2039) climate change, viz. yield reduction by 4.5 to 9%, depending on the magnitude and distribution of warming (Aggarwal and Sinha, 1993). Since agriculture makes up roughly 15% of India's GDP, a 4.5 to 9.0% negative impact on production implies the cost of climate change to be roughly at 1.5% of GDP per year. Consequently, it is projected that India's population could reach 1.4 billion by 2025 and may exceed China's in the 2040s (Bhat, 1998). If agricultural production is adversely affected by climate change, livelihood and food security in India would be at risk. Because the livelihood system in India is based on agriculture, climate change could cause increased crop failure and more frequent incidences of pests. Therefore, the future challenges to achieve and maintain country’s food security in the developing countries, especially in India will be more complex and demanding due to the ever-increasing human population; higher demand for, and intensification of, resource use; and increased per capita consumption. Most aspects of climate change will persist for centuries, even if emissions of CO2 are stopped immediately.
Green house gas (GHG): Their role in climate change The sun is the enormous source of energy for earth. Solar radiation penetrates through the atmosphere and reaches to the earth's surface. Some part of the solar radiation is absorbed by the earth's surface and the majority of the radiation is reflected back into the atmosphere. The warmed earth's surface again released the heat in the form of thermal infrared (IR) radiation which is of long wavelength. Both the solar and radiated infrared (IR) spectra are absorbed by a specific group of gasses having dipole moment and radiate heat in all directions. These gasses may be released into the atmosphere through natural and anthropogenic means. The more of these gases that exists, the more heat is prevented from escaping into space and, consequently, the more the earth heats up. This increase in heat is called the greenhouse effect and the gasses are known as greenhouse gasses (GHGs). The examples of such gases are carbon dioxide, methane, nitrous oxide, ozone, water 2
vapour, and a diverse group of fluorocarbons. Although water vapour is the most abundant GHGs, it is a relatively ineffective one. The ability of these GHGs to trap heat depends on its capacity to absorb and to re- emit radiation and on how long the gases remain in the atmosphere (Shahid et al., 2014). One interesting fact about these gasses is: without the greenhouse gasses, the earth's temperature would be below freezing. The earth requires GHGs to some extent to maintain its ecology. The problem of greenhouse effect started slowly after the commencement of the industrial revolution during 1750. The atmospheric concentration of CO2 has increased from 280 parts per million by volume (ppmv) in 1750 to 395.4 ppmv in 2012 and is currently increasing at the rate of 1.9 ppmv yr-1 (NOAA, 2012; Table 2). In fact, the observed monthly average CO2 concentrations in the atmosphere crossed the 400 parts per million thresholds, for the first time in April and May 2013, in several observing stations across the world (Barrow/Alaska—USA, Alert/Canada, NyÅlesund/Norway, Izaña/Canary Islands-Spain, and Mauna Loa/Hawaii—USA) (Bala, 2013; Carrasco, 2014). Atmospheric CH4 concentration has increased from about 0.715 ppmv in 1750 to 1.826 ppmv in 2012 and it is increasing at the rate of 7 ppbv year-1 (IPCC, 2007; EPA, 2015; Table 2). Similarly, the concentration of N2O in the atmosphere has increased from about 0.270 ppmv in 1750 to 0.323 ppmv in 2012 and it is increasing at the rate of 0.8 ppbv yr-1 (IPCC, 2007; Table 2). Tropospheric ozone (O3) concentration increased from 0.237 ppmv in 1750 to 0.337 ppmv in 2013 (IPCC, 2013; Blasing, 2014; Table 2). Table 2: Concentration, atmospheric life and global warming potential (GWP) of GHGs GHGs Conc. (ppmv) Atmospheric Life GWP Reference (Years) CO2 395.4 100 1 NOAA, 2012 CH4 1.82 12 24.5 IPCC, 2007; EPA, 2015 N2O 0.323 114 320 IPCC, 2007; EPA, 2015 O3 0.337 Hours-days IPCC, 2013; Blasing, 2014 The anthropogenic enrichment of GHGs in the atmosphere and the cumulative radiative forcing of all GHGs have increased the average global surface temperature of 0.74°C since the late 19th century, with the current warming rate of 0.13°C decade-1 (IPCC, 2007). The observed rate of increase of the global mean temperature is in excess of the critical rate of 0.1°C decade-1 beyond which the ecosystems cannot adjust. These changes may affect the soil organic carbon (SOC) pools, dynamics, and structural stability and may disrupt cycles of water, carbon (C) and nitrogen (N) resulting in adverse impacts on biomass productivity, biodiversity and the environment (Shahid et al., 2014). In the recent report of IPCC (2014), the GHGs emission was reported to be increased at the rate of 1.3% year-1, which is now 2.2% year-1 during 2000-2010. About 40% of this increase is from Asia, mostly China and India. Therefore, there is increasing international pressure on India and China, for which there is a need for constant monitoring to reduce the emission of GHGs. In 2008, the top carbon dioxide (CO2) emitters were China, the United States, the European Union, India, the Russian Federation, Japan, and Canada (Fig. 2; EPA, 2015). These data include CO2 emissions from fossil fuel combustion, as well as Fig. 2: Global CO2 emissions from cement manufacturing and gas flaring. Together, these fossil fuel combustion and industrial sources represent a large proportion of total global CO2 processes (million metric tons of CO2) emissions (EPA, 2015). Agriculture releases to the atmosphere significant amounts of CO2, CH4, and N2O (Paustian et al., 2004; Smith et al., 2007). CO2 is released mostly from the microbial decay or burning of plant 3
litter and soil organic matter (IPCC, 2007; EPA, 2015). CH4 is produced when organic materials decompose in oxygen-deprived conditions, particularly from fermentative digestion by ruminants, from stored manures, and from rice grown under flooded conditions (Shahid et al., 2014). N2O is generated by the microbial transformation of nitrogen in soils and manures, and is often enhanced where available nitrogen (N) exceeds plant requirements, especially under wet conditions at high rate of nitrogenous fertilizer application (Shahid et al., 2014). Collectively CH4 and N2O are responsible for about 20% of the anticipated global warming (Smith et al., 2007). Rice paddies contribute approximately 10–13% of the global CH4 emission (Crutzen and Lelieveld, 2001). The major sources of GHGs are shown in Table 3. Table 3: Major sources of global emissions of greenhouse gases (IPCC, 2007; EPA, 2015) GHGs Sources CO2 Industrial activities, deforestation, burning of fossil fuels, land use changes, microbial decomposition of organic matter, and eruption of volcanoes CH4 Agricultural activities (rice cultivation and ruminants), waste management, energy use, wetlands, organic decay, termites, natural gas and oil extraction, biomass burning, and refuse landfills N2O Agricultural activities, such as nitrogenous fertilizers, and burning of biomass and fossil fuels. Fluorinated gases Industrial processes, refrigeration, and the use of a variety of consumer (F-gases) products contribute to emissions of F-gases, which include hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6).
Climatic variability and change: Possible impacts on agricultural production The agricultural production system is sensitive to weather and thus directly affected by climatic variability and change. Recent and projected increases in these gases will have two possible consequences on global crop production. The first consequence of rising atmospheric CO2 and other associated GHGs could lead to a significant increase in global surface temperatures, with its major consequences for precipitation frequency and amounts. Moreover, the differential extent to which the increase in CO2 and other anthropogenic GHGs alters surface temperature and water availability is likely to vary temporally and geographically, with subsequent increases in climatic extremes and thus affect the climate stability (IPCC, 2007). The second consequence is related to the role CO2 plays in photosynthesis and growth. C3 plants (95% of the 250,000 or more plant species) evolved at a time of high atmospheric CO2 (4–5 times present values), but concentrations appear to have declined to relatively low values during the past 25–30 million years (Bowes, 1996). The values have been low for long enough that evolution has selected for a small percentage of plants (the rest 3-4% of all known plant species), principally tropical C4 grasses that have maximum photosynthetic rates even at the current low CO2 concentrations. The recent rise and projected increase in atmospheric CO2 represents an upsurge of an essential resource in the C3 plants only. To that end there are, literally, hundreds of studies showing that both recent and projected increases in atmospheric CO2 can significantly stimulate growth, development and reproduction in a wide variety of C3 plants (Kimball et al., 2002). Regarding our nutritional security, this rising level of atmospheric CO2 may result in a significant decline (10–15%) in protein content in major food crops including barley, wheat, soybean and potato (Taub et al., 2007). In addition, the upward flow of water through the xylem and phloem tissues of the crop plant may be hampered due to its physiological effect of closing stomata under enriched CO2 environment. As a result, uptake of key micro and macro nutrients from the soil environment will reduce and accordingly our daily dietary requirement will also need some modifications (Loladze, 2002). Climate change will bring higher temperatures and additional climatic extremes, particularly more extreme precipitation. Evidence of the impact of climate change on the transmission of food 4
and water borne diseases is a function of a number of sources, such as the seasonality of food borne and diarrheal disease, changes in disease patterns that occur as a consequence of temperature, and associations between increased incidence of food and waterborne illness and severe weather events (Rose et al., 2001). Climatic constrains alters the range of infectious diseases, while weather affects the timing and intensity of outbreaks. Two early manifestations of climate change, particularly global warming, could be an expansion in the geographic range and seasonality of disease, and the emergence of outbreaks occurring as a consequence of extreme weather events (Epstein, 2001).
Adaptation and mitigation strategy The most important challenge for agriculture in the twenty-first century is the need to feed an increasing numbers of people – most of who are in developing countries like us – while at the same time, conserving the local and global environment in the face of limited soil and water resources and growing pressures associated with socioeconomic development and climate change (Tubiello, 2012). In short, to feed more mouths, somehow, the mankind will face certain ill effects of climate change. Hence, adaptation will be needed to protect livelihoods and food security under climate change situation. Proposed measures for adaptation to the changing climate are as follows (Howden et al., 2007): • Altering inputs, varieties and species for increased resistance to heat shock and drought, flooding and salinization; altering fertilizer rates to maintain grain or fruit quality; altering amounts and timing of irrigation and other water management; altering the timing or location of cropping activities. • Managing river basins for more efficient delivery of irrigation services and prevent water logging, erosion and nutrient leaching; making wider use of technologies to “harvest” water and conserve soil moisture; use and transport water more effectively. • Diversifying income through the integration of activities such as livestock raising, fish production in rice paddies, etc. • Making wider use of integrated pest and pathogen management, developing and using varieties and species resistant to pests and diseases; improving quarantine capabilities and monitoring programmes. • Increasing use of climate forecasting to reduce production risk. • Matching livestock stocking rates with pasture production, altered pasture rotation, modification of grazing times, alteration of forage and animal species/breeds, integration within livestock/crop systems, including the use of adapted forage crops, re-assessing fertilizer applications and the use of supplementary feeds and concentrates. • Undertaking changes in forest management, including hardwood/softwood species mix, timber growth and harvesting patterns, rotation periods; shifting to species or areas more productive under new climatic conditions, planning landscapes to minimize fire and insect damage, adjusting fire management systems; initiating prescribed burning that reduces forest vulnerability to increased insect outbreaks as a non-chemical insect control; and adjusting harvesting schedules. • Introducing forest conservation, agro-forestry and forest-based enterprises for diversification of rural incomes. • Altering the catch size and effort and improving the environment where breeding occurs; reducing the level of fishing in order to sustain yields of fish stocks. Reducing emission of GHGs, enhancing removals and avoiding emissions are the three pillars of mitigation strategy for climate change. (a) For carbon dioxide: • Aggregation: Increase in stable micro-aggregates through the formation of organomineral complexes encapsulates C and protects it against microbial activities. 5
• • • •
Humification: To sequester C in humus, addition of N, P and S are needed. Translocation into the sub-soil: Translocation of SOC into the sub-soil. Formation of secondary carbonates: CaCO3 and MgCO3 Burial of SOC-laden sediments: Transport of SOC-enriched sediments to depressed sites and/or aquatic ecosystems • Plantation of deep-rooted plants: Horticulture and Agroforestry • Restoration of degraded lands: Adoption of conservation tillage and mulch farming techniques, soil and water conservation, and use of suitable crop rotations. • Reduced tillage: C may sequester under no-tillage. • Application of biochar: Organic material used up slowly under limited oxygen. Highly stable, porous, active surfaces. • Establishment of bio-energy plantation with a large potential for biomass production • Afforestation of agriculturally marginal soil. • Growing species containing cellulose and other resistant material • Soil fertility management: Integrated use of fertilizer and manures, addition of compost and biosolids which stimulates soil biological activity and humification efficiency besides improving soil structure lead to increase in SOC sequestration. Water management through irrigation can drastically increase SOC content. (b) For methane: • Upgrading the equipment used to produce, store, and transport oil and gas can reduce many of the leaks that contribute to CH4 emissions. Methane from coal mines can also be captured and used for energy. • Reducing methane emission from rice field: Alternate wetting and drying, efficient rice variety, application of organic inputs under aerobic condition, crop rotation and application of Mn, Fe, S fertilizers etc. can help. • Integrated rice and livestock systems: Use a highly digestible feed for livestock. • Better irrigation water efficiency • Integrating animal manure waste management systems, including biogas capture and utilization • Capture landfill CH4 (c) For nitrous oxide: • Water management: Drainage increases the emission of N2O • Judicious application of N-fertilizer • Application of nitrification inhibitors and slow-release fertilizers • Integrating animal manure waste management systems • Restoring land by controlled grazing
References and further reading Aggarwal PK, Sinha SK, 1993. Effect of probable increase in carbon dioxide and temperature on productivity of wheat in India. Journal of Agricultural Meteorology 48: 811–814. Anonymous, 2015a. http://www.census.gov/ipc/www/idb accessed 30th January 2015. Anonymous, 2015b. http://www.nicra-icar.in/ accessed 30th January 2015. Bala G, 2013. Digesting 400 ppm for global mean CO2 concentration. Current Science 104: 47-48. Bhat PNM, 1998. Demographic estimates for post-independence India: A new integration. Demography India 27: 23-57.
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Blasing TJ, 2014. Current greenhouse gas concentrations. doi:10.3334/CDIAC/atg.032 on Carbon Dioxide Information Analysis Centre (CDIAC), Oak Ridge, Tennessee, last updated on February, 2014. Bowes G, 1996. Photosynthetic responses to changing atmospheric carbon dioxide concentration, In: Baker N (ed.), Photosynthesis and the Environment, Dordrecht, Kluwer Publishing, pp. 387–407. Carrasco JF, 2014. The challenge of changing to a low-carbon economy: A brief overview. Low Carbon Economy 5: 1-5. http://dx.doi.org/10.4236/lce.2014.51001 Crutzen PJ, Lelieveld J, 2001. Human impacts on atmospheric chemistry. Annual Review of Earth and Planetary Sciences 29: 17–45. EIA, 2008. Emissions of greenhouse gases in the United States 2008. www.eia.gov/oiaf/1605/ggrpt/ pdf/0573(2008).pdf EPA, 2015. United States Environmental Protection Agency. www.epa.gov/climatechange/science/ indicators. Accessed on 2nd February, 2015. Epstein PR, 2001. Climate change and emerging infectious diseases, Microbes and Infection 3: 747–754. Howden M, Soussana JF, Tubiello FN, 2007. Adaptation strategies for climate change. Proceedings of the National Academy of Sciences 104: 19691-19698. IPCC, 2007. Climate Change 2007: The Physical Science Basis, contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge, UK: Cambridge University Press. IPCC, 2013. Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge, United Kingdom and New York, USA, 2013. Kaur R, Rajni, 2012. Climate change and its possible impacts on agriculture in India. Indian Farming 62: 10–15, 18. Kimball BA, Kobayashi K, Bindi M, 2002. Responses of agricultural crops to free air CO2 enrichment. Advances in Agronomy 77: 293–368. doi: 10.1016/S0065-2113(02)7701 7-x Loladze I, 2002. Rising atmospheric CO2 and human nutrition: toward globally imbalanced plant stoichiometry? Trends in Ecology and Evolution 17: 457–61. NOAA, 2012. Earth System Research Laboratory, Global Monitoring Division. http://www.esrl. noaa.gov/gmd/ccgg/trends Paustian K, Babcock BA, Hatfield J, Lal R, McCarl BA, McLaughlin S, Mosier A, Rice C, Robertson GP, Rosenberg NJ, Rosenzweig C, Schlesinger WH, Zilberman D, 2004. Agricultural mitigation of greenhouse gases: Science and policy options. Council on Agricultural Science and Technology (CAST) Report, R141 2004, ISBN 1-887383-26-3, p. 120. Rose JB, Epstein PR, Lipp EK, Sherman BH, Bernard SM, Patz JA, 2001. Climate variability and change in the United States: potential impacts on water and food borne diseases caused by microbiological agents. Environmental Health Perspectives 109: 211–21. Saha S, Sehgal VK, Chakraborty D, Pal M, 2015. Atmospheric carbon dioxide enrichment induced modifications in canopy radiation utilization, growth and yield of chickpea [Cicer arietinum L.)]. Agricultural Forest Meteorology 202: 102–111. doi: 10.1016/j. agrformet.2014.12.004 Shahid M, Bhattacharyya P, Nayak AK, 2014. Advanced techniques for assessment of soil health, GHG emissions and carbon sequestration in rice under changing climatic scenario and 7
mitigation strategies. Compendium from winter school. Crop Production Division, CRRI, Cuttack, Odisha, India, 11th November to 1st December, 2014. p. 229. Smith P, Martino D, Cai Z, Gwary D, Janzen H, Kumar P, McCarl B, Ogle S, O’Mara F, Rice C, Scholes B, Sirotenko O, 2007. Agriculture. In: Metz B, Davidson OR, Bosch PR, Dave R, Meyer LA (eds), Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York, USA. Taub DR, Miller B, Allen H, 2007. Effects of elevated CO2 on the protein concentration of food crops: a meta- analysis’. Global Change Biology 14: 565–75. Tubiello F, 2012. Climate change adaptation and mitigation: challenges and opportunities in the food sector. Natural Resources Management and Environment Department, FAO, Rome. Prepared for the High-level conference on world food security: the challenges of climate change and bio energy, Rome, 3-5th June 2008. World Meteorological Organization, 1992. International Meteorological Vocabulary. 2nd eds., WMO, Geneva, Switzerland.
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Meteorological variations in the hill climate of Nagaland P. Chowdhury, Tasvina R. Borah, Dibyendu Chatterjee, Imtisenla Walling and Bidyut C. Deka Introduction
Nagaland is one of the eight North-Eastern Hill states in India, located between 25o10’ N and 27 4’N Latitude and 93o15’E and 95o20’E Longitude with a total geographical area of16,579 km2 in the northern extension of the Arakan-Yoma ranges. The state shares along international border with Myanmar in the East and is bounded by state of Assam in the west and north, Arunachal Pradesh in the North and Manipur in the south. Currently, Nagaland has 11 districts (Fig.1), viz., Kohima, Dimapur, Kiphre, Longleng, Mokokchung, Mon, Peren, Phek, Tuensang, Wokha and Zunheboto, 114 sub-districts, 26 towns (19 statutory and 7 census towns) and 1428 villages. Physiographically, the state has vast undulating terrain and mountainous landscapes that include high hill slopes, hilly dissected terrains, denudational hill slopes, undulating upland, and narrow valleys with presence of perennial streams and moisture supporting rich biodiversity. o
Fig. 1: GIS Map of Nagaland
Fig. 2: Agro-climatic zones of northeast India
Climate The north eastern hill region is classified into six agro-climatic regions, viz. Alpine, Mild Tropical Hill, Mild Tropical Plain, Sub-tropical Hill, Sub-tropical Plain and Temperate Alpine Zone (Fig. 2). Nearly eighty percent area of Nagaland comes under first four categories of agro-climatic zones. Meteorologically, a 30 year period of observation establishes the climate of a region. The climate in Nagaland is influenced by several factors such as altitude, geographical coordinates, distance from sea and wind. Nagaland has a typical monsoon climate with variations ranging from tropical to temperate conditions. Monsoon is the longest lasting for five months from May to September with May, June and July being the wettest months. Owing to varied topography and relief annual rainfall varies from 1000 mm to over 3000 mm at different places with an average of 2000 mm. Atmospheric mean temperature varies from 15oC to 30oC in summers and from less than 5o to 25oC in winters. Altitude variation in Nagaland is among the prime factors affecting climate and weather conditions. Relief features such as high mountains act as barriers for the movement of the Monsoon winds. Low temperature, high rainfall on windward slopes, comparatively dry on the leeward side and heavy precipitation in the form of snow at the mountain tops are the main features of the climate. The general trend of meteorological parameters is as under: (a) Air temperature: During the year 2007-14, mean maximum and minimum temperatures were in the range of 15.0 to 33.0oC and 5 to 25oC, respectively. The highest maximum temperature 9
was recorded 37.3°C during May, whereas the lowest minimum temperature was recorded 5.0°C during January. June was the hottest month and January was the coolest month of during the period. A thirteen year trend analysis (1998-2010) of annual maximum temperature (Tmax) and minimum temperature (Tmin) showed an increasing trends of 0.077oC year-1 (Fig. 3) and decreasing trend of – 0.132oC year-1, respectively (Fig. 4).
Fig. 3: Deviation of Max Temp from normal Fig. 4: Deviation of Min Temp from normal max temp 27.02oC min temp 20.0oC (b) Rainfall: Analysis revealed that total yearly rainfall recorded during 2007-08 to 2013-14 was in the range of 977.9 to 2064.2 mm. The highest total yearly rainfall (2064.2 mm) was found during the year 2007-08, whereas the lowest total yearly rainfall (977.9 mm) was recorded during the 2009-10. The rainy days recorded during the study period were in the range of 79 to 121 days. The highest total monthly rainfall was recorded 500.3 mm on the month of August during the year 2007-08. During monsoon season (June to September) of 2014, total monthly rainfall deficit was estimated 82.3% with a 10.3% surplus rainfall during July. The pre-monsoon rainfall was 104% deficient during the same year. During year 2014, the normal observed rainfall was 1511.4 mm whereas observed rainfall was 1173.5 mm which was 22.36% less than normal rainfall of Nagaland. The seasonal rainfall variation had shown that maximum 66.68% rainfall was recorded during monsoon season followed by 20.22%, 10.93% and 2.16% during the pre-monsoon, post monsoon and winter season respectively (Fig. 5). Analysis of thirteen years data (1998-2010) showed a decline in the total annual rainfall by 0.660 mm year-1. The deviation pattern of annual rainfall from the normal in Nagaland for the period 1998 to 2009 is depicted in the Fig. 6.
Fig 5. Seasonal normal rainfall distribution pattern in Nagaland
Fig 6. Deviation pattern of annual rainfall from the normal in Nagaland (Source: Annual Report-2009-10, ICAR) (c) Relative humidity: During the study period (2007-14) the mean monthly maximum and minimum relative humidity was recorded in the range of 70.0 to 85.0% and 20.0 to 66.0%, respectively. Based on the average data during the period 2009 to 2013, the highest relative humidity was recorded from July to October. The morning hours were more humid as compared to the afternoon hours. (d) Sunshine hours: The maximum sunshine hour was observed only during October when the sky was clear, while lesser sunshine hour was recorded during monsoon season (June to 10
September). The trend analysis of 13 years (1998-2010) showed an increasing trend in the total annual sunshine duration of 1.840 h year-1. (e) Soil temperature: Soil temperature was recorded both in the morning and evening from 5 to15 cm depths and it showed a decreasing trend with the increase in soil depth. The minimum and maximum soil temperature at 5 cm depth was recorded in the range of 2.9 to 18.2oC and 15.3 to 25.5oC respectively. The Minimum and maximum soil temperature at 15 cm depth was recorded in the range of 2.8 to 15.6oC and 9.9 to 21.8oC. (f) Pan evaporation: During the year 2007-08, 2008-09 and 2009-10, the total monthly evaporation was recorded less than total monthly rainfall during April to November, May to October and June to October respectively. The total monthly pan evaporation was recorded in the range of 38.0 to 147.0 mm. The trend analysis of 13 years (1998-2010) revealed that the pan evaporation data underestimate the actual evaporation rate. (g) Reference Evapotranspiration: Thirteen years (1998-2010) trend analysis of weather parameters of ICAR Nagaland Centre showed an increasing trend of reference evapotranspiration during the months of February to July, and a decreasing trend during the months of August to January with an annual decreasing trend of 4.72 mm year-1. The maximum increasing trend was recorded in the month of May followed by April and February. Similarly, the maximum decreasing trend was recorded in December followed by November. This phenomena could be attributed to the annual trends of daily mean of maximum relative humidity-RHmax (+0.365%), minimum relative humidity-RHmin (–0.895%), maximum temperature- Tmax (0.179oC), minimum temperature-Tmin (0.221oC), total number of rainy days (+0.717), and wind speed (–0.034 m s-1). Hence, that may cause more water vapour to remain suspended in air; thereby reducing the evaporative demand of the atmosphere. Both monthly and weekly water surplus and water deficit models for Nagaland from long-term weather data were developed for irrigation scheduling and better crop planning. 200
50 0
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O ct
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W ater su rp lu s & d eficit, y (m m )
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0 -10 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51
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y = 0.0633x 5 - 1.6401x 4 + 12.035x 3 - 12.681x 2 - 66.611x - 0.109 Month (x) R2 = 0.9885
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Fig. 5 Monthly water surplus and deficit model
y = 8E-06x5 - 0.0007x 4 + 0.0157x3 + 0.2095x2 - 5.0379x - 6.9063 R2 = 0.9192 Week (x)
Fig.6 Weekly water surplus and deficit model
Conclusion
The meteorological variations showed that air temperature was 15 to 33oC in summers and 5 to 25oC in winters. The seasonal variation of rainfall showed a significant high in monsoon season followed by pre-monsoon and post monsoon seasons, respectively. Thirteen years trend analysis (1998-2010) revealed that the pan evaporation data underestimated the actual evaporation rate. Therefore, pan evaporation data should not be used for irrigation water management under Nagaland condition. Hence, this information could be useful for crop planning, irrigation scheduling and water management under the existing trend of global climate change scenario.
References and further reading Annual Report-2007-08, 2008-09, 2009-10, 2010-11, 2011-12, 2012-13 and 2013-14, ICAR Research Complex for NEH Region, Umiam, Meghalaya. QRT Report, 2006-11. ICAR Research Complex for NEH Region, Jharnapani, Nagaland. Anonymous, 2012. Nagaland Action Plan on Climate Change, 2012. 11
Resource conservation options in the context of climate change D.J. Rajkhowa Introduction Climate change and climatic variability are now a reality. The impact of climate change on agriculture is being witnessed in different countries of the world. Countries like India are more vulnerable to climate change in view of huge population directly depend on agriculture, with low coping mechanisms. Rising temperatures and extreme events, such as sudden droughts and floods, mean that it will be even harder to meet the growing demand for food, fiber and fuel, especially for poor countries with high population growth. Climatic aberrations will seriously affect the poorest section of the society who heavily relied on climate-sensitive sectors such as rainfed agriculture and fisheries (Samra et al., 2004; Prasad and Rana, 2006). Reduction in crop, livestock, and fishery productivity due to climate change /climatic variability is well predicted and there are variations in perceptions about the intensity and consequences of climate change. Agriculture in the North East is facing multifarious challenges like degradation of natural resources, especially land degradation with jhum cultivation, fragmentation of land, occurrence of dry spells in undulating hill topography, securing food for the increasing population and low crop productivity. The shift in the climate scenario, low availability of resources and lack of mitigation strategies with the farmers makes the challenges in North Eastern agriculture further complex. Since 80% of the crop area is under rainfed, future climate change and variability will potentially impact agricultural production pattern in the region (Anon. 2004, GOI). In the climate change front, the average temperature is projected to rise by another 3–5°C in this region of India during the latter third of this century (Cline, 2007). The results of the recent study (Ravindranath et al., 2011) indicate that the majority of the districts in North East India is subject to climate induced vulnerability presently and in the near future. The poorest section of the society heavily relied on climate-sensitive sectors such as rainfed agriculture and fisheries (Samra et al., 2004; Prasad and Rana, 2006). The erratic pattern of rainfall (both spatio-temporal), higher frequency of extreme rainfall events, less rain in June-August, and more in September-October, and frequent flash floods and longer dry periods in various parts of the region manifests the impact of climate change (Barthakur et al., 1989). Summer monsoon rainfall has been decreasing significantly during the last century at an approximate rate of 11 mm per decade. The study conducted by Saikia et al. (2012) further substantiate the average reduction in total rainfall, number of rainy days as well as occurrence of dry spells and one day extreme rainfall events in the region. On the other hand, the annual mean maximum temperature in the region is rising at the rate of + 1.11°C per decade (Singh and Ngachan, 2012). The shift in the climate scenario, low availability of resources and mitigation strategies with the farmers make the challenges in North Eastern agriculture further complex. The agricultural production system in the NEH region is predominantly rainfed and monocropped. Slash and burn agriculture (jhum) is still practised on steep slopes in almost all the hill states, except Sikkim, with reduced cycle of 2-3 years as against 10-15 years in the past. About 0.88 m ha area is still under shifting cultivation in the NE region. The huge amount of biomass (about 10 t ha-1) burnt annually in jhuming that leads to release of the considerable amount of CO2. The region, once endowed with rich genetic diversity of flora and fauna, has been denuded due to human activities and adoption of unscientific and unsustainable land use system. With rapid increase in human and livestock population and the rising demand of food, feed, fuel, fodder, fibre, timber and the other developmental activities, the farmers have been forced to exploit forestland and water resources in complete defiance of the inherent potential. This has resulted in a progressive decrease in forest cover, loss of biodiversity, serious soil erosion leading to depletion of plant nutrients, water, gradual degradation and decline in land productivity and drying up of 12
perennial streams as well as causing serious ecological imbalances. The gradual degradation of these resources is of prime concern and calls for location-specific measure to conserve, utilise and manage these resources for optimising production on a sustained basis without adversely affecting its quality. Some of the resource conservation options are briefly described below.
Conservation Agriculture Conservation Agriculture (CA) aims to conserve, improve and make more efficient use of natural resources through integrated management of available soil, water and biological resources combined with external inputs. It contributes to environmental conservation as well as to enhanced and sustained agricultural production. It can also be referred to as resource-efficient /resource effective agriculture. Over the past couple of decades, the concept of CA has emerged globally as a response to issues of declining soil health and it offers a means to minimize soil degradation as well as to recoup soil health for sustaining agriculture. The concept of CA is rooted in three scientifically sound and proven principles: (i) Minimum/no soil disturbance: In contrast to plowing, CA advocates little or no soil disturbance through minimum or zero tillage (direct seeding). Zero tillage aims to enhance and sustain farm production by maintaining a permanent or semi-permanent organic soil cover that protects the soil from sun, rain and wind and to feed soil micro-organisms and soil fauna. Soil micro-organisms and soil fauna take over the tillage functions and soil nutrient balancing. Mechanical tillage disturbs this process. Therefore, zero or minimum tillage and direct seeding are important elements of CA. Furthermore, by not tilling the soil, farmers can save their labour, time and fuel costs as compared with the conventional method of farming. (ii) Permanent or semi-permanent soil cover: Permanent or semi-permanent soil cover needs to be integrated into farming systems to obtain additional benefits. Crop residues will not be burnt since they are made part of the permanent soil cover, and air pollution will thus be reduced where burning is stopped. Residues from previously planted crops, other cover crops and green manure cover crops are utilized for permanent or semi- permanent organic soil cover. The dead-residue biomass of the cover crops functions as mulch, protecting the soil physically from sun, rain and wind. Soil mulch reduces water evaporation, conserves moisture and helps moderate soil temperature, making conditions more hospitable for below-ground biota. Mineralization and nutrient losses are reduced, and more satisfactory levels of organic soil matter are built up and maintained. (iii) Crop rotations: A varied crop rotation is also important to avoid disease and pest problems. The use of crop rotation will help control pests, diseases, weeds and other biotic factors. Wellbalanced crop rotations can neutralize many of the possible negative aspects of minimum/no-tillage, such as pest build-up, as they increase the diversity of favourable insects and organisms that can help maintain checks on the spread and impact of pests and diseases.
Integrated Farming Systems The majority of the farmers of the country are small and marginal. In order to achieve food and livelihood security, the adoption of Intensive integrated farming Systems is one of the welcomed approaches. Integrated Farming System (IFS) is based on the concept that “there is no waste”, and “waste is only a misplace resource which can become a valuable material for another product. IFS has been considered as a very effective mechanism to tackle the menace of climate change as it accommodates different farming components, like crop-animal-fish-horti-MPT etc. suitably, use of natural resources can be done more judiciously, promotes internal flow of bio-resources to maintain soil health, promotes conservation and recycling of rain water, generate employment opportunities and there by promotes food and nutritional security. Demonstration of suitable IFS model in the farmer's field in the region in a participatory mode resulted enhanced income, improved resource use efficiency, increase in employment opportunity and better natural resource conservation. 13
Rain Water harvesting and its efficient utilization Water is a vital component of agricultural production and is essential to increase both quantity and quality of produce. Agriculture is the major user of water in most countries and currently this sector faces the enormous challenge of producing almost 50 % more food by 2030 and doubling almost 50 % more by 2050. This has to be achieved with less water resources, mainly because of increased competition arising out of growing population pressure, urbanization, industrialization and climate change. Although the NER is endowed with high average annual rainfall (2500 mm), but analysis of long term weather data shows reduction in total rainfall as well number of rainy days. In view of limited access to irrigation, small farmers need to develop water conservation insitu or ex-situ, rainwater harvesting systems to maximize on-farm water management. Water management can also improve by having a greater diversification option for water sources, such as small streams, shallow well, bore well and rainwater storage. Other options such as microirrigation (drip, sprinkler), water lifting devices (gravity, manual and pumps – motorized, solar etc.). Creating awareness among the people about environmental and anthropogenic facts behind floods, droughts, scarcity of water and sustainable development of water resources of the region by involving the people and utilizing indigenous knowledge and technology at the same time seems to be an urgent need. About 3000 micro-rain water harvesting structures “Jalkund” was demonstrated in different states of the NEH region in participatory mode. The water harvested during the rainy season is being utilized by the farmers for growing high value crops like strawberry, vegetables, etc. during the post monsoon season besides being utilized for meeting the requirement for pigs and poultry. Demonstrations were also undertaken on efficient utilization of harvested water through drip/sprinkler irrigation. Adoption of such technologies helped the farmers for increasing their cropping intensity and income.
In-situ moisture conservation practices In –situ moisture conservation through utilizing crop residues /weed biomass, etc. as mulch along with conservation tillage holds promise for crop intensification and enhanced water use efficiency. The successful cultivation of toria, lentil, pea, buckwheat, etc. in rice fallows was demonstrated in the farmer’s field. Intercropping of groundnut, soybean etc. in maize along with conservation tillage in the terrace land situation resulted in enhanced productivity, higher water use efficiency, higher soil C build-up and better moisture conservation. A good crop of toria could be harvested utilizing the residual moisture.
Zero tillage cultivation of crops in rice fallows Zero tillage cultivation of toria, pea, lentil, etc. was also very much successful in the farmer’s fields of different states of the NEH region, which enabled the farmers to get an additional income of Rs. 10,000 to 15,000 ha-1. Raised and Sunken Bed system was also demonstrated in the farmer’s field for crop diversification (Rice –vegetables) and enhanced water use efficiency.
Suitable Land use model for conservation technologies for arresting soil loss, improving carbon sequestration and land productivity A land use model involving natural forest, fodder crops, leguminous cover crops, intercropping of maize + legume, residue management, conservation tillage, micro-rain water harvesting structure, hedge rows, toe tranches, were developed for climate resilient hill agriculture.. The cropping sequence adopted along the slopes was top-bottom approach: natural pine forest with catch pits - fodder crops - cover crops - maize + legume intercropping - rice based system at the foot hills. Among the different cropping systems, fodder crop based system, registered maximum soil organic carbon (SOC, 1.80%) and SOC stock (29.7 t ha-1) followed by cover crop based system 14
(1.61 %, 26.8 t ha-1) at the end of three cropping cycles. Similarly, the soil loss was reduced by 27.8, 19 and 9.2 folds due to adoption of fodder crops, cover crops and maize + legume intercropping systems compared to farmers practice, respectively. On an average, the developed land use model when considered as a single unit with all components enhanced SOC stock by 10 % and reduced soil loss significantly over farmers practice.
Carbon management Carbon in the form of CH4 and CO2 is the major player in contributing to this global climatic shift. Soil being one of the potential sinks for global carbon stock (3.5%), soil carbon management holds the key for developing effective adaptation strategy that would sustain the agricultural production, environmental health vis-à-vis food security and livelihood. Adoption of appropriate package of practices, cropping systems, restoration of degraded lands, agro-forestry interventions, conservation agriculture, integrated nutrient management, etc. has great potential to sequester carbon and reduce the emission of methane, nitrous oxide and carbon dioxide to the atmosphere. The Plant biomass production in the region is very much higher which may be utilized for improving soil health (Rajkhowa and Kumar, 2013). Efficient conversion of different plant biomass utilizing earthworms and cellulose decomposing microbes was also reported by Mahanta et al. (2014). Soil carbon sequestration is yet another strategy towards mitigation of climate change. Carbon sequestration builds soil fertility, improves soil quality, improves agronomic productivity, protect soil from compaction and nurture soil biodiversity. Increased organic matter in soil, improves soil aggregation, which in turn improves soil aeration, soil-water storage, reduces soil erosion, improves infiltration, and generally improves surface and groundwater quality. It is also helpful in the protection of streams, lakes, and rivers from sedimentation, runoff from agricultural fields, and enhanced wildlife habitat. Besides these, it has major roles in mitigating greenhouse gas emissions and in tackling the effects of climate change.
Organic matter management Soil organic matter (SOM) is the primary sink and a source of plant nutrients in natural and managed terrestrial ecosystems. Soil organic matter plays key role in crop sustainability and it is directly or indirectly responsible to the soil physical environments suitable for the growth of crops. Application of organic manure in nutrient starved soils enables farmers to maintain their soil quality and to maximize their crop production with negligible soil erosion and nutrient runoff. Besides, it increases the fertilizer use efficiency of crops. The application of organic manure in the form of FYM, poultry manure, pig manure has long been practiced in the region, but inferior quality of these manures hardly meets the crop demands for nutrients. Therefore, there is a necessity to develop and popularize technology for preparation of quality compost that suits the resource poor farmer of the region. Since the availability of crop residues and weed biomass is plenty in the NE hill region (weed biomass 5-20 t ha-1) and their utilization for production of quality compost hold promise. The other attractive options for SOM management are: mulching, growing cover crops, green manuring, crop residue incorporation etc.
Biochar application in soil Biochar is a fine-grained, highly porous charcoal that helps soils to retain nutrients and water. The carbon in biochar resists degradation and can sequester carbon in soils for hundreds to thousands of years, providing a potentially powerful tool for mitigating anthropogenic climate change. There is a large body of peer-reviewed literature quantifying and describing the crop yield benefits of biochar-amended soil. Field trials using biochar have been conducted in the tropics over the past several years. Most shows positive results on yields when biochar was applied to field soils and nutrients were managed appropriately. 15
Integrated nutrient supply system The integrated nutrient supply system envisages conjunctive use of chemical and organic fertilizers is the most ideal system of nutrient management. The conjunctive use of chemical fertilizers and organic manure (NPK+FYM) enhanced organic carbon, soil available nutrients, soil aggregation, water infiltrability, microbial biomass-C and microbial population compared to use of chemical fertilizers alone. The system enhances nutrient-use efficiency, maintains soil health, enhances yields and reduces cost of cultivation. The beneficial effects of balanced and integrated nutrient management on soil health in terms of physical, chemical and biological attributes and overall crop productivity have very well been demonstrated by the Long Term Fertilizer Experiments in India and abroad. There is a need to augment the supplies of organic manures (farm yard manure, green manure, and compost/vermicompost) and fortified & customized fertilizers supplying secondary and micronutrients to have IPNS on a sound footing. The research conducted at ICAR RC for NEH region revealed that the adoption of the INM package (agricultural lime @ 10% LR + recommended doses of NPK and organic manure @ 5 t ha-1 fertilizers) increased the productivity of maize, groundnut and soybean to the tune of 2-3.8 folds over farmers’ practices. Besides increasing crop yield, INM package has improved the health of the acid soil (increase in pH, reduction in exchangeable acidity and Al, increased availability of major nutrients, increased concentration of exchangeable Ca and Mg). Integrated use of FYM @ 5 t ha-1, half the recommended doses of fertilizers (N, P and K) and biofertilizers (PSB & Azotobacter @ 250 g ha-1 seedling root dip treatment) produced more than 7 t ha-1 rice (var. Shah Sarang) yield in the acid soils of Meghalaya. The use of biofertilizers is still minimal in hilly and mountainous regions and requires to be promoted by producing effective strains with enhanced shelf life. A variety of biofertilizers that could be popularized are nitrogen fixers (Rhizobium, Azotobacter, Azospirillum), phosphate solubilizing bacteria (PSB), blue-green algae, mycorrhizae and plant growth promoting rhizobacteria (PGPR).
Watershed approach Watershed as a tool for soil and water conservation (SWC) measures as well as for the socioeconomic development of community is already a widely accepted fact. The component of the watershed includes socio-economic survey for analysis of resource status, water harvesting structures, construction of bench and half moon terraces along with other agronomic measures for SWC, introduction of HYV crops, fruits and vegetables etc.
Conclusion It is now well realized that climate variability and climate change are a reality. A more certain assessment of the impacts and vulnerably of hill agriculture sector and comprehensive understanding of adaptation options is essential. A multi pronged strategy of using indigenous coping mechanism, a wider adaptation of the existing technologies and concerted research and development efforts for evolving new technologies are needed for adaptation and mitigation. The mitigation of CO2 emission from agriculture could be achieved by increasing C sequestration in soil, which implies the storage of C as soil organic matter (Lal, 2004; Pathak et al., 2011). Judicious nutrient management, increased use of organic manure and biomass recycling, etc. will lead to increase the SOC pool. Conservation agriculture with adoption of resource conservation technologies with no or minimum tillage, residue management, appropriate crop rotations have potential to enhance the use efficiency of natural resources such as water, air, fossil fuel and soil. Such technologies can improve the sustainability of agriculture by conserving the resource base with higher input use efficiency and also mitigating GHGs emissions.
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Development of climate resilient crop varieties, rain water harvesting, modifying sowing/planting dates, crop diversification, adoption of location specific integrated farming system, conservation agriculture, integrated pest management, crop insurance, increase nutrient use efficiency, water harvesting, agro-forestry intervention, improved weather –based agro-advisory, protected cultivation, intercropping/mixed cropping, use of renewable source of energy, creation of seed bank, custom hiring centre, use of indigenous technical knowledge etc. are some of the adaptation strategies for agriculture under climate change scenarios.
References and further reading Anon, 2004. Ministry of environment and forests, GOI, India’s National communication to UNFCC (NATCOM), New Delhi, 2004. http://www.natcomindia.org/ natcomreport.htm. Cline WR, 2007. Global Warming and Agriculture: Impact Estimates by Country, Peterson Institute for International Economics, Washington DC. Mahanta K, Jha DK, Rajkhowa DJ, Kumar M, 2014. Isolation and evaluation of native cellulose degrading microorganisms for efficient bioconversion of weed biomass and rice straw. Journal of Environmental Biology 35: 721–725. Lal R, 2004. Soil carbon sequestration in India. Climate Change 65: 277–296. Pathak H, Byjesh K, Chakrabarty B, Aggarwal PK, 2012. Potential and cost of low carbon sequestration in Indian agriculture: Estimates from long term field experiments. Field Crops Research 120: 102–111. Prasad R, Rana R, 2006. A study on maximum temperature during March 2004 and its impact on rabi crops in Himachal Pradesh. Journal of Agrometeorology, 8: 91–99. Rajkhowa DJ, Kumar M, 2013. Biowaste utilization for improving health and productivity of acid soils in North East India. Current Science 104: 11-12. Ravindranath et al., 2011. Climate change vulnerability profiles for North east India Current science 101: 384-394. Samra JS, Singh G, Ramakrishna YS, 2004. Cold wave during 2002-2003 over North India and its effect on crops. The Hindu, P.6, January 10. Singh AK, Ngachan SV, 2012. Climate change and food security in North Eastern Region of India In: Singh AK, Ngachan SV, Munda GC, Mahapatra KP, Choudhury BU, Das A, Rao Ch. Srinivasa, Patel DP, Rajkhowa DJ, Ramakrushna GI, Panwar AS (Eds.) Carbon Management in Agriculture for Mitigating Greenhouse Effect. Published by ICAR Research Complex for NEH Region, Umiam, Meghalaya, India. pp. 1-16. Saikia US, Goswami B, Rajkhowa DJ, Venkatesh A, Ramachandran, Kausalya, Rao VUM, Venkateswarlu B, Ngachan SV, 2012. Sans comprehensive intervention rainfed agriculture in the North Eastern Region of India will suffer from intermittent droughts and floods as indicated by standardized precipitation index. National Symposium on ‘Climate Change and Indian Agriculture: Slicing Down the Uncertainties’, CRIDA, Hyderabad 22-23 January, 2013.
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Soil Health Management in the context of climate change S. Hazarika Introduction Soil is an important component of terrestrial ecosystems that support life on the earth. A healthy soil is fundamental for sustained agricultural productivity and the maintenance of vital ecosystem processes. A healthy soil enhances plant productivity, promotes plant, animal and human health, maintains water and air quality, ensures proper retention and release of water and nutrients, resists erosion and nutrient loss, supports a diverse community of soil organisms, and resists anthropogenic stresses and climatic perturbations, so resists environmental degradation. Healthy soil is the foundation of the all farming systems. It produces healthy crops that in turn produce healthy foods, healthy people and healthy livestock.
Anticipated Impact of projected climate change on soil health Climate change predictions considered by the Intergovernmental Panel on Climate Change (IPCC) include an increase in atmospheric CO2 concentration, an increase in air temperature, changes in precipitation and prevalence of extreme climate events. For instance, global temperature change of 1.6–6.4°C by 2100, atmospheric CO2 concentration increases by up to 550 ppm and precipitation change by at least 20% have been predicted (IPCC, 2007). However, the predicted changes vary geographically and therefore; the consequences of these changes on soil health will be location specific. With the predicted climate change, soils are expected to be exposed to the drier environment for a longer period of time and, on the other hand, more likely to be subjected to an intense rate of wetting and flooding. Under these conditions, soils are more prone to structural breakdown due to slaking and dispersion. With the combined reduction in aggregate stability (increase in soil erodibility) and intense rainstorm events (increases in erosivity), the surface soil structure will be more prone to degradation with the formation of a seal/crust. This has serious implications on soilwater entry and water use efficiency (WUE). Soil surface seals and crusts resulting from aggregate breakdown, reduce the soil infiltration rate and may induce erosion by increasing runoff. The actual impact on the structure under predicted climate change will be dependent on soil types and on their vulnerability. Under climate change, higher incidences of fire and flooding are also expected. Fire usually reduces soil aggregate stability and can induce, enhance or destroy water repellency depending on the extent of heating and its duration (Shakesby and Doerr, 2006). Reduced infiltration is often observed in the burnt area relative to un-burnt area due to induced water repellency and sealing of pores due to collapse of soil surface aggregates. Flooding of soils will occur more often due to intense storms as well as the predicted sea water level rises. It has been predicted globally that sea water can rise by 26–59 cm (IPCC, 2007). This together with the prevalence of flooding incidences will result in submergence and loss of much of low lying prime agricultural land in many parts of the world. Periodic flooding can also drastically change soil structure and the physical properties associated with it directly via slaking and dispersion (Sedgley, 1962) or indirectly via adverse impact on soil fauna, e.g. earthworms (Thonon and Klok, 2007). Furthermore, flooding by sea water will result in salinity and sodicity problems leading to deterioration of soil structure and crop yield losses. In areas where climate is expected to become warmer and wetter, microbial activity may increase, resulting in increased soil-air CO2 concentrations leading to production of more carbonic acid in soil. High carbonic acid concentration and increased rainfall events result in intense leaching of basic cations from the soil system which implies more acidification of soil. Increased 18
acidification enhances lime requirement for amelioration of soil acidity. Absence of adequate liming may deteriorate soil quality to a large extent and soil may become unproductive. Soil organic matter (SOM) is essential in maintaining physical, chemical and biological functions in soil and it is considered as one of the most important attributes of soil health. Changes in SOM contents depend on the balance between carbon inputs from vegetation and carbon losses through decomposition. Increasing temperature strongly stimulates decomposition of SOM that lead to reduced SOM content in soil. Rates of SOM decomposition vary widely between different soil carbon pools. As the labile fractions of soil organic carbon can be decomposed faster than its relatively recalcitrant fractions, atmospheric warming can induce a gradual reduction in the proportion of labile carbon fractions which implies a reduction in quality of soil organic matter. Quantitative and qualitative reduction in soil organic matter can reduce the water and nutrient holding capacity of soil, weaken the buffering capacity of soil, degrade soil aggregate stability and physical structure rendering it more susceptible to erosion losses, decrease soil biological activity, and can bring many other associated changes which will ultimately lead to gradual decline in soil health and crop productivity (Kumar, 2011). Soil respiration is one of the important measures of soil health, because it reflects the capacity of soil to support life (micro- and macro-organisms and plant roots) and is directly related to other functions, such as organic matter decomposition, nutrient mineralization–immobilization and microbial activity in general. Research finding reveals that a rise in average soil temperature by 20C would result in an increase in soil respiration by 22%. This would suggest that global warming could be increased via increasing soil respiration. In places where the climate will be hotter and wetter, nutrient cycling will be faster and consequently significant loss of nutrients from the soil system by high intensity rainfall is expected to occur. Effects of global warming on different processes and pathways of the N cycle are going to be very complex as several interactions will be involved and the overall effects are likely to be site specific. With the rising atmospheric temperature N mineralization in soil is expected to rise that may cause an increase in nitrogen losses from the soil profile. Usually ammonia volatilization from soil with high pH (alkaline/alkali soil) is significant after urea application. It may be further enhanced due to increase in atmospheric temperature as a consequence of climate change. Nitrous oxide (N2O) is one of the main greenhouse gases and acidic soils have a higher N2O production activity than neutral arable soils because soil acidity increases the denitrification potential. In addition to long-term heavy nitrogen fertilization, subsequent soil acidification would also enhance the N2O flux in the field. For example, in tea-growing soils (acidic), the N2O flux was proportional to temperature, increasing with an increase in soil temperature to reach peaks in summer and autumn and then decline with incoming winter (Tokuda and Hayatsu, 2004). In contrast, soil drying decreased N2O flux. Hence, the effects of climate change and variability regarding N2O fluxes would differ in different soils, farming systems and locations. Climate change is likely to increase wind and water erosion rates, especially where the frequency and intensity of precipitation events grows. Erosion rates also will be affected by climate-induced changes in land use and soil organic carbon contents. However, increased erosion in response to climate change cannot be assumed for all parts of the globe.
Likely impact on the soil health of northeast region There have been some conspicuous changes in temperature as well as rainfall pattern in northeast India over the past century. The annual maximum and mean temperature in northeast India during 1901-2003 has increased significantly by a rate of 1.02°C and 0.60°C 100 years-1, respectively (Deka et al., 2009). Atmospheric temperature in the region is further projected to rise by approximately 3°C to 5°C during the latter third of this century (Cline, 2007). There is a reduction in the annual as well as the monsoon rainfall over the years in the northeast. In the recent 19
times, the alarming deficits in annual as well as monsoon rainfall resulted in severe droughts across the region. The anticipated effects of climate change on soil health of north east are: i.
ii.
iii.
iv. v. vi.
Intensification of soil acidity: More than 80% soils are acidic in nature and aluminium toxicity and P deficiency are the major soil related constrains for production of crops/fodders in these soils. Intensification of soil acidy due to climate change may emerge as a major challenge for maintaining sustainable soil health in the region. Increasing top-soil loss due to erosion: Soil loss due to water erosion in north east hilly region is substantially higher (>40 t ha-1annum-1) than the national average (16 t ha-1annum1 ). Increased frequency of high intensity precipitation, even for a short span of time, will further intensify the soil loss from the disturbed hilly slopes of the region. Loss of soil organic matter due to rise in temperature (increased decomposition), decreased precipitation (reduction in PNP) and short-term increased frequency of high intensity precipitation (SOM loss due to erosion). Loss of SOM may lead to gradual decline in soil health and crop productivity in the region. Increased denitrification loss of nitrogen due to intensification of soil acidity as soil acidity increases the denitrification potential of soil. Increased nutrient loss through leaching and surface runoff due to increased frequency of high intensity precipitation. Expected higher loss of organic matter in soil (reasons stated above) and associated increase in soil bulk density (more soil compaction) will reduce the soil water availability to crops. Higher evaporative loss of water from soil under the rising atmospheric temperature and increased frequency of drought (winter months) will enhance the water requirement in agriculture. Decline in water availability (less rainfall events) against rising demand of water will emerge as one of the major challenges to the agricultural productivity in the region.
Strategies to counteract/minimize the effect of climate change on soil health Soil health management provides a holistic approach with economic and environmental benefits through better soil functioning in the context of climate change adaptation. Poor soil health (soil acidity, toxicity and deficiency of nutrients, low SOM, etc.) is often a yield limiting factor for crop production in the northeast and increases the potential for runoff, erosion and other environmental losses, as well as drought. These problems are anticipated to become more severe with climate change. Thus more holistic soil health management will become increasingly necessary as an adaptation and mitigation strategy. (i) Organic matter management: Improved soil health increases soil infiltration and soil aeration, which reduce the effects of high precipitation on runoff, erosion, and compaction, and thus also reduce denitrification and nitrous oxide losses. Increased soil water retention and rooting depth decrease the soil’s susceptibility to drought stress. To address these issues, SOM management can play a significant role. The options for managing SOM are reduced tillage, cover cropping, better crop rotations, or application of organic matter like manure and compost. Better management of carbon biomass and increasing soil carbon level results in net sequestration of carbon from the atmosphere to the soil. (ii) Controlling soil pH change: Given that soil acidification is a continuous process in most soils, re-acidification after lime application will result in the release of CO2 from bicarbonate. Hence, improving SOM status in soil should be the priority to obtain a long-term benefit since it moderates fluctuations of soil pH through improvement in buffer capacity of soil. In place of lime application of other soil amendments such as, livestock manure (poultry/pig- have high ash alkalinity), compost and biochar may be other options to manage soil acidity. (iii) Controlling soil erosion: Soil erosion is a widespread and serious degradation process in the hill regions of north east. High intensity rains, even for a short span, can cause devastating soil 20
erosion on cultivated lands on moderate to steep slopes where runoff rates are high and the ground has an inadequate vegetative cover. Runoff and resulting soil erosion can be substantially reduced through the adoption of minimum to no-tillage techniques combined with optimizing soil cover (cover crops, residues, mulch). On steeper slopes, soil erosion can also be reduced by planting cross-slope vegetation; using soil and water conservation structures, such as terraces, earthen bunds and tied ridges to optimize water capture and infiltration; and creating grassed waterways to convey excess water safely off the slopes. (iv) Improving water storage in soil (more crop per drop): Water storage in the soil depends on many factors, including rainfall, soil depth, and soil texture (clay content) and soil structure. Soil management can influence rainwater infiltration and the capacity of the soil to reduce soil water evaporation and store water in the soil. Ground cover management can have highly beneficial effects on soil surface conditions, SOM content, soil structure, porosity, aeration and bulk density. Improvements in these properties influence infiltration rates, water storage potential and water availability to plants. These improvements also increase the effectiveness of rainfall and enhance productivity. They also reduce rates of erosion, the dispersion of soil particles and the risks of water logging and salinity in dry lands. (v) Rainwater harvesting (more crops per rain drop): Besides improving water storage in soil, rainwater harvesting and management is a useful strategy to store the excess water and reuse it during the dry season. Use of harvested water for life saving irrigation of crops through micro irrigation-system technologies (e.g. drip irrigation) is a practical adaptation to climate change and variability. This strategy is especially relevant to rainfed agriculture and is relevant to smallholder farmers to intensify production systems. (vi) Improving soil structure: Soils are compacted due to repetitive hoeing or ploughing. Compacted soils are seriously affected by dry spells as well as high intensity rainfall. During dry periods, compaction limits root growth and the plant’s access to moisture and nutrients. Compaction facilitates water erosion during high intensity precipitation. Sub-soiling to break up compacted layers can have a huge beneficial effect on root growth and soil productivity. Prevention measures such as minimum tillage in combination with a plant or litter cover should be adopted to avoid soil compaction. This provides organic matter that enhances the activity of soil fauna (e.g. earthworms and termites). The burrowing of these soil organisms breaks up compacted layers and incorporates SOM from the surface into the soil. Also, specific cover crops with strong roots such as radish or pigeon peas can be used to penetrate and break up compacted soil layers. In time, practices such as conservation agriculture (that combine minimized soil disturbance with increased soil cover and crop diversification) will allow SOM to build up and increase the soil’s resilience to climate change. Such practices build up a cover of protective vegetation or litter that foster the biological-tillage activity of macro-fauna (such as earthworms) that burrow and make channels for air and water. These practices also incorporate and break down organic matter in the soil. (vii) Biochar application: Biochar application has been promoted in agricultural practice that creates a win-win situation by improving soil quality and enhancing agricultural sustainability concomitant with mitigating greenhouse gases (GHG) emissions. Recently biochar application gained momentum because of its capability of carbon sequestration, reducing soil compaction, improves soil physical condition, controlling soil pH, enhancing nutrient uptake from the soil and helps to reduce nitrous oxide emission (Lehmann et al., 2005; Lehmann, 2007). Production plant biomass in the north east is substantial and there is ample scope to produce biochar from these biomasses. Soil application of biochar may be one of the options to minimize the impact of climate change on soil health of this region. (viii) Holistic approach: Agro-forestry interventions, conservation agriculture, integrated farming system and integrated nutrient management are some of the holistic approaches appropriate for the farmers of north east for improving the soil health to minimize the anticipated adverse impact of projected climate change. 21
Conclusion A healthy soil is fundamental for sustained agricultural productivity and the maintenance of vital ecosystem processes. Soil health management provides a holistic approach with economic and environmental benefits through better soil functioning in the context of climate change adaptation. It may reduce runoff, erosion, leaching, denitrification etc., while increasing C sequestration and nutrient use efficiency.
References and further reading Cline WR, 2007. Global Warming and Agriculture: Impact Estimates by Country (Washington: Center for Global Development and Peterson Institute for International Economics). Deka RL, Mahanta C, Nath KK, 2009. Trends and Fluctuations of Temperature Regime of North East India. In: Panigrahy S, Ray SS, Parihar JS (Ed.) Impact of Climate Change on Agriculture. ISPRS Archives XXXVIII-8/W3 Workshop Proceedings. Space Application Centre, Ahmedabad. pp. 376-380. IPCC, 2007. The climate change 2007: the physical science basis. Cambridge University Press, Cambridge. Lehmann J, Liang BQ, Solomon D, Lerotic M, Luizao F, Kinyangi J, Schafer T, Wirick S, Jacobsen C, 2005. Near-edge X-ray absorption fine structure (NEXAFS) spectroscopy for mapping nano-scale distribution of organic carbon forms in soil: Application to black carbon particles. Global Biogeochemical Cycles 19: 1-12. Lehmann J, 2007. A handful of carbon. Nature 447: 143-144. Kumar M, 2011. Evidences, Projections and Potential Impacts of Climate Change on Food Production in Northeast India. Indian Journal of Hill Farming 24: 1-10. Sedgley RH, 1962. Effects of disruption and flocculation o pore-space changes in beds of clay aggregates. Soil Science 94:357–365. Shakesby RA, Doerr SH, 2006. Wildfire as a hydrological and geomorphological agent. EarthScience Reviews 74:269–307. Thonon I, Klok C, 2007. Impact of a changed inundation regime caused by climate change and floodplain rehabilitation on population viability of earthworms in a lower River Rhine floodplain. Science of the Total Environment 372: 585–594. Tokuda SI, Hayatsu M, 2004. Nitrous oxide flux from a tea field amended with a large amount of nitrogen fertilizer and soil environmental factors controlling the flux. Soil Science and Plant Nutrition 50: 365–374.
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Soil testing for optimization of agricultural production in the climate change scenario Jurisandhya Barik Bordoloi Introduction Changes in global climate have thrown multitudes of challenges for agricultural production. In the field of agriculture, the climatic aberrations have triggered constraints like multiple nutrient deficiencies in soil and plant systems, poor use efficiencies of applied nutrients, rapid loss of nutrients from the soil profile and so on. These and many other constraints have made it even more difficult to diagnose the kind and magnitude of deficiencies/ disorders that prevail in a soil- plant system. This has warranted a closely knit diagnostic system to operate with the utmost efficiency, which will be the prerequisite for success of any management strategy devised to overcome the aforesaid challenges. Maintenance of soil fertility or the availability of essential plant nutrients in adequate amount is achieved through the application of external inputs like organic manures, bio fertilizers and inorganic inputs like synthetic chemical fertilizer. Fertilizers, being costly inputs are beyond the reach of the common farmers of our country. Again application of fertilizer, less than required is useless, on the other hand, applying more than required is needless and even harmful which may cause environmental pollution leading to health hazard for both humans and animals. Economic use of fertilizer other soil amendments in appropriate quantities along with other agricultural practices will help to develop productive agricultural soil and avoid the risk of environmental hazard and pest and disease management problems associated with nutrient deficiencies and the overuse of fertilizers. Soil testing is the only way to economize the use of fertilizers and other amendments. Soil testing refers to the chemical testing of soils that provides guidelines for precise application of amendments so as to enhance crop productivity on one hand while maintaining soil fertility at optimum level on the other.
Sampling the soil Soil sampling is the collection of requisite amount of soil for testing in such a way to represent the field area, the fertility or quality attributes of which is to be delineated. That means the sample collected should reflect the true fertility status of the field There is no fixed number of samples. The number rather depends on the level of variability existing in the area sampled. More the variability more is the requisite number of samples. The objective should be to duly represent the area concerned. If the field is levelled and soil appears to be uniform, only one sample if taken properly could be enough for an area of 4-5 ha. If the field has undulating topography- lowland, upland and slopes, it has to be sampled separately
Sampling depth The roots of most of the field crops are confined in 0-15cm depth and hence sampling upto 15cm is enough. However, soil samples from areas growing deep rooted crops, especially plantation crop like citrus, arecanut, etc. need to be collected from beyond 1 meter depth. The objective of soil testing is also to be considered while deciding upon sampling depth.
Time of sampling Samples can be collected at any time, except the rainy season provided there is sufficient time for analysis. However, winter is the best time for soil sampling. For delineating any specific problem, samples can be collected as and when required. 23
Soil sampling- activities involved There are 3 major activities involved in the overall sampling procedure: (a) sample collection, (b) sample preparation and (c) sample storage. (a) Sample collection Step I: Select the sampling points at random: Sampling points should be selected randomly as shown in Fig. 1. Step II: Clean the sample point with a spade. Sampling point should be cleaned by removing any vegetation, etc. so as to expose the soil surface (Fig. 2). Step III: Insert the spade into soil to desired depth and remove a lump of soil. A ‘V’ shaped cut is formed. The lump of soil should be discarded (Fig. 3). Step IV: Insert the spade by the side wall of the ‘V’ shaped cut mark down to the bottom. A uniform slice of soil is thus scooped out (Fig. 4). Step V: Collect the scooped out soil in polythene bags. Clean polythene bags should be used (Fig. 5). The sample bags should be tied properly so as to avoid any mix ups during processing. (b) Sample preparation Wet soil samples collected from the field cannot be stored as changes occur with time in storage condition. Moreover, a large amount of soil is collected for making a composite sample, whose volume is to be reduced for making storage convenient. The following steps are to be systematically followed to prepare the soil samples for testing. Step I: Drying: Samples should be spread on paper in the shade for drying. Sun drying is strictly prohibited (Fig.6). Step II: Sample size reduction: Sample should be divided into 4 parts by drawing a ‘+’ sign through it (Fig. 7a.). Discard the soils from the opposite corners. Mix remaining soil, divide into 4 parts and again discard from corners (Fig. 7b). Step III: Grinding of the soil samples by a wooden mortar and pestle (Fig. 8). Step IV: Sieving: Ground soil samples should pass through a 2 mm sieve to separate roots, stones and other debris from the soil (Fig. 9). (c) Sample storage Care should be taken to send the collected samples as soon as possible for analysis. However, until analysed, processed samples should be stored in polythene bags- properly tied and tagged (Fig. 10). The tag attached with each sample should include: (a) name of the farmer, (b) village/ location of the field, (c) date of sampling, (d) sampling depth, and (e) name of the standing crop(s). Any other relevant information such as purpose of analysis, fertilization history, future cropping plan, etc. should be provided separately. This information shall help in generating precise recommendations out of the analysis.
Sampling points in slopes/ hills (must represent top, middle and bottom reaches of the slope)
Fig 1: Selection of the sampling points at random
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Fig. 2: Cleaning of the sample point with spade
Fig. 3: Making a V-shaped cut
Fig. 4: Scooping of uniform slice of soil
Fig. 5: Collection the scooped out soil in polythene bags
Fig. 6: Drying
Fig. 7a: Sample size reduction by drawing a ‘+’ sign
Fig. 7b: Discard the soils from the opposite corners
Fig. 8: Grinding
Fig. 9: Sieving
Fig. 10: Final packing and tagging of the processed samples
Parameters to be assessed through soil testing in a climate change scenario The very objective of soil testing in a changing climate scenario is to assess accurately the soil health indicators (minimum data set) which will form the basis for any mitigation/ adaptation strategy to be taken up. Soil health indicators- what are they? Soil health indicators are a composite set of measurable physical, chemical and biological attributes which relate to functional soil processes and can be used to evaluate soil health status, as affected by management and climate change drivers. Defining soil health in relation to climate change should consider the impacts of a range of predicted global change drivers such as rising atmospheric carbon dioxide (CO2) levels, elevated temperature, altered precipitation (rainfall) and atmospheric nitrogen (N) deposition, on soil chemical, physical and biological functions (French et al., 2009). Determination of how predicted changes in climate relate to soil health will thus depend on our capacity to clearly define soil health properties and their relationship with specific soil functions, including complexity associated with interactive effects of climate change. The most important parameters to be assessed through soil testing to gauge the implications of climate change along with their level of relevance are listed in Table 1. 25
Table 1. Soil health indicators to be assessed to form the minimum data set in climate change scenario Inclusion in
Soil health indicator
Soil processes affected
Landscape
Relevance a minimum data set
Soil structure
Aggregate stability, organic matter turnover
Porosity
Air capacity, plant available water capacity, relative field capacity Soil water availability and movement
Infiltration Physical
Bulk density Soil depth and rooting
Soil total C and N
Volumetric basis for soil reporting Productivity potential; uncertain whether trends can be discerned over long time periods Field capacity, permanent wilting point, Water and chemical retention and macro pore flow, texture transportation, yield Soil water and nutrient movement, soil Soil physical movement, organic matter stabilisation, C and N fixation input and movement Biological and chemical activity thresholds Soil acidification, salinisation, electrical conductivity, soil structural stability Plant and microbial activity thresholds Soil structural decline; leachable salts Plant available nutrients and potential Capacity for crop growth and yield; for loss environmental hazard (e.g. algal bloom) Plant residue decomposition, organic matter Loss of organic matter, soil aggregate storage and quality, macro aggregate formation Formation, total organic C, soil respiration rate, nutrient supply Metabolic activity of soil organisms, net inorganic N-flux from mineralization and Microbial activity, nutrient supply immobilisation C and N mass and balance Soil structure, nutrient supply
Soil respiration
Microbial activity
Soil/plant available water and distribution Soil protective cover pH Chemical
EC Plant available N, P, K Soil organic matter Light fraction or Macro-organic matter
Biological
Aggregation, surface seal, indication of Medium water and chemical retention and transportation Soil crusting, reduced seed germination, High aeration, water entry Potential for leaching, productivity, erosion High
Mineralisable C and N
Soil structural condition; compaction Plant available water capacity, subsoil salinity
Microbial activity 26
Frequent
Occasional/ frequent Occasional
Low Medium
Frequent Occasional
High
Frequent
Medium
Frequent
Medium
Frequent
Medium Medium
Frequent Frequent
High
Frequent
High
Occasional
High
Occasional/ Frequent Occasional
High
Microbial biomass C and N
Microbial activity
Soil structure, nutrient supply, pesticide degradation Substrate quality Biochemical activity, nutrient supply
Microbial quotients Substrate use efficiency Microbial diversity Nutrient cycling and availability Other microbiological Soil structure, labile carbon, Km, Vmax, Ki, Q10 indicators, enzyme activity Source: Dalal and Moloney, 2000; Gregorich et al., 1994; Haynes, 2008; Kinyangi, 2007; Reynolds et al., 2009
High High High High
Occasional/ Frequent Occasional Occasional Occasional
References and further reading Dalal RC, Moloney D, 2000. Sustainability indicators of soil health and biodiversity, In: Hale P, Petrie A, Moloney D, Sattler P (eds), Management for sustainable ecosystems. Centre for Conservation Biology, Brisbane, pp. 101–108. French S, Levy-Booth D, Samarajeewa A, Shannon KE, Smith J, Trevors JT, 2009. Elevated temperatures and carbon dioxide concentrations: effects on selected microbial activities in temperate agricultural soils. World Journal of Microbiology and Biotechnology 25: 1887–1900. Gregorich EG, Carter MR, Angers DA, Monreal CM, Ellert BH, 1994. Towards a minimum data set to assess soil organic matter quality in agricultural soils. Canadian Journal of Soil Science 74: 367–385. Haynes RJ, 2008. Soil organic matter quality and the size and activity of the microbial biomass: their significance to the quality of agricultural soils, In: Huang Q, Huang PM, Violante A (eds), Soil mineral-microbe-organic interactions: theories and applications, Springer, Berlin, pp. 201–230. Kinyangi J, 2007. Soil health and soil quality: a review. Draft publication. Available on: http:// www.cornell.edu.org Accessed on: 10 Feb 2015 and www.worldaginfo.org, Accessed 10 Feb 2015. Reynolds WD, Drury CF, Tan CS, Fox CA, Yang XM, 2009. Use of indicators and pore volume function characteristics to quantify soil physical quality. Geoderma 152: 252–263.
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Abiotic Stresses: Its influence on crops and possible mitigation strategies Christy B.K. Sangma Introduction Agriculture is persistently at risk of abiotic stresses and it has been aggravated by climate change in the present era. These stresses are usually unavoidable factors making the agrarian resources vulnerable as the time passes. Vulnerability of agricultural crops also depends on the level of defense mechanisms the crops have to various stresses. These stresses are inherent part of every ecosystem and must influence the ecosystem beyond its normal range of fluctuation to have an adverse effect on the functioning of the crops in a significant way. These stresses will influence crops in a variety of ways, e.g. drought, salinity, heavy metals, anoxia, nutrient stress, high wind, wildfires, flood and excessive cold or heat. Other stresses which affect in a lesser level are parent material, pH levels, high radiation, compaction and pollutions. When crop suffers from stresses it experience a series of morphological, physiological, biochemical and molecular changes that adversely affect growth and in turn reducing the productivity and sometimes the loss in yield might be more than 50% of their potential yield. Currently agriculture is meeting great challenges to ensure a sufficient food supply while sustaining the productivity and quality standards. An effort has to be made to improve the productivity of the agricultural crops by efficiently utilizing the available natural resources. One favourable approach is to increase the resistance level of crops to abiotic stresses by incorporating the emerging genetic engineering and molecular techniques or by selecting and breeding those species which are resistant to stress. Another effort will be to improve the efficiency of agricultural water use while simultaneously reducing adverse environmental impacts and focusing on increasing our productivity per unit of water in order to achieve “More crops per drop”.
Types of abiotic stresses and their effect on crops There are many stresses of crops in the environment and some of these are summarized below: a) Drought: One of the most important abiotic stresses affecting plants is water stress. It is the major yield limiting factor in many agricultural lands by affecting the growth and development of crops and limits its productivity. A crop requires a certain amount of water to complete its life cycle and under the drought conditions, crops dry up unless it has some adaptation mechanisms to survive as we can see in the case of perennial plants. Photosynthesis is the major process to be affected by the water stress as with water deficit stomata closes and causes reduced CO2 diffusion, which is one of the most important components for photosynthesis. Under water stress crops allocate more photosynthates to structures that are used to acquire resources, limiting plant growth and in this way more resources will be allocated to roots to acquire more water. Consequently, moisture-stressed plants have a higher root:shoot ratio. Aboveground plant parts are relatively smaller, shorter and have smaller leaves and canopies. b) Temperature: Temperature stresses can also devastate the crops as they are very sensitive to changes in normal temperatures (15°C to 45°C). High temperature stress is occured when there is a rise in temperature beyond the threshold for the certain period of time to cause damage to crops. Good production of the crop depends on the growing season, photoperiod and length of day. The fluctuation of normal temperatures may lengthen or shortened the growing periods and various stages of crops will be affected, e.g. germination, leaf number and size, plant height, number of tillers and finally reducing the yield. It also causes considerable pre- and post-harvest damages, fruit discoloration and damage, scorching of leaves and twigs, leaf senescence and abscission, shoot and root growth inhibition. Photosynthetic rate will also be significantly affected by temperature. 28
Cold stress is another major abiotic factor leads to crop loss. It results from temperature (chilling: 0-15°C and freezing :< 0°C) cool enough to produce injury to the crop. If the temperature is too cold it can lead to cold stress, also called chilling stress and extreme forms of cold stress can lead to freezing stress. The symptoms of chilling stress are surface lesions, chlorosis, necrosis, desiccation, tissue break down and water soaked appearance of tissues, reduced leaf expansion and wilting. Under extremely cold conditions, the cell liquids can freeze outright, causing plant death. Low temperature may affect several aspects of crop growth; viz., survival, cell division, photosynthesis, water transport, growth, and finally crop yield. At flowering, cold stress may cause delayed flowering, bud abscission, sterile or distorted flowers, while at grain filling the source-sink relation is altered, the kernel filling rate is reduced and ultimately small sized, unfilled or aborted seeds may occur. c) Flood: Flood is a major problem as none of the crops can survive except rice. However, rice also cannot survive if submerged under water for long periods of time. At present, about 20 million hectares of the world’s rice-growing area is at risk of occasionally being flooded to submergence level, particularly in major rice-producing countries such as India and Bangladesh. Major flooding events are likely to increase in frequency with the unevenness rainfall pattern. d) Wildfires: Direct burning of plants through wildfires will cause the cell structure to break down through melting or denaturation. A wildfire may be beneficial for the ecosystems to burn out every once in a while so that new plants or organisms can begin to grow and thrive. Even though it is healthy for an ecosystem, a wildfire can still be considered an abiotic stressor, because it puts an obvious stress on individual organisms within the area. e) Salinization: High amounts of salt taken up by a plant can lead to cell desiccation, as high levels of salt outside a plant cell will cause water to leave the cell, a process called osmosis and disturbance in the mineralization process. Salinity is a major abiotic stress worldwide claiming agriculture lands and affecting productivity. Continuing salinization of arable land is expected to have overwhelming global impact, resulting in a 30% loss of agricultural land over the next 25 years and up to 50% loss by 2050. Overall, it has been estimated that the world is losing at least 3 ha of arable land every minute due to soil salinity. Globally, an estimated 34 million irrigated hectares are salinized and the global cost of irrigation-induced salinity is equivalent to an estimated US$11 billion per year. f) Heavy metal pollution: Plant uptake of heavy metals can occur when plants grow in soils fertilized with improperly composted sewage sludge. High heavy metal content in plants can lead to complications with basic physiological and biochemical activities such as photosynthesis. One example of heavy metal is chromium (Cr) is a highly phytotoxic heavy metal affecting crop productivity and human health via entering the food chain. g) Nutrient stress: Nutrient stress is also one of the abiotic stresses affecting the productivity of the agricultural crops. The plant is affected through an imbalance of nutrition, or via toxicity. The seventeen essential nutrients required for growth and reproduction and these are carbon (C), hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S) which comes under macronutrients and iron (Fe), zinc (Zn), manganese (Mn), copper (Cu), boron (B), molybdenum (Mo), chlorine (Cl) and nickel (Ni). These minerals have to be present in a balance way to avoid stress. E.g. when plants P starved, cell division in the primary root meristems gradually reduces and the cells start to prematurely differentiate until total inhibition of cell elongation and loss of meristematic activity. Nitrogen is fundamental for biological molecules, such as nucleotides, amino acids, and proteins affecting the growth and development. h) Wind stress: Wind stress can either directly damage the plant through force or the wind can affect the transpiration of water through the leaf stomata and cause desiccation. Strong winds also cause excess water loss from the spikelets, resulting in sterility. i) Soil acidity: Majority of the cultivated land in Northeast suffers from acidity and aluminium toxicity. Aluminium is one of the most common metals in the world. The problems are particularly 29
serious in the laterite soils. Such soil conditions make the cultivation very difficult as lime treatment is required. The detrimental effects the acid soils have on plants are rarely based on the toxic effects of aluminium. Aluminium acts particularly on the roots, probably because the cell division is slowed down in the top part of the plant; this results in growth retardation and relatively short and thick side roots. Other consequences are cell death and a reduced uptake of nutritions, especially phosphorus.
Plants mechanism for survival Plant responses to abiotic stresses are dynamic and complex and undergo several physiological and growth changes to modify their architectures for proper development. When in adverse or limiting growth conditions, plants respond by activating tolerance mechanisms at multiple levels of organization (molecular, tissue, anatomical and morphological), by adjusting the membrane system and the cell wall architecture, altering the cell cycle and rate of cell division and metabolic alterations. There are several mechanism and followings are some of them. a) A plant’s first line of defense against abiotic stress is in its roots. If the soil holding the plant is healthy and biologically diverse, the plant will have a higher chance of surviving stressful conditions. b) Plants response to drought is by decreasing in leaf growth, which helps to maintain the cell turgor and reduces the transpiration area. In normal abscission, an organized leaf senescence process, which includes the loss of chlorophyll, precedes leaf shedding. With severe drought, leaves may be shed at early age. Some leaves show drought associated signs of leaf rolling, folding and curling. These mechanisms are potentially cost-effective way for plants to deal with drought stress. Wilting is another mechanism to deal with the stress and it varies with the species. Temporary wilting is the visible drooping of leaves during the day followed by rehydration and recovery during the night. c) Growth inhibition: Growth of vegetative and reproductive tissues is constrained by cell initiation shortages, cell enlargement problems, and inefficient food supplies. Cell enlargement depends upon hydraulic pressure for expansion and is especially sensitive to water stress. Cell division in generating new cells is also decreased by drought. d) Shoot growth: Internal water deficits in trees constrain the growth of shoots by influencing development of new shoot units (nodes and internodes). A period of drought has a carry-over effect in many species from the year of bud formation to the year of expansion of that bud into a shoot.
Management or mitigation strategies Though a crop or a plant has defense mechanisms to survive several abiotic stresses these might not be possible to tackle the extreme climate situations in the near future. The human intervention in terms of management practices or genetic engineering tools may be the better options. The following are some of the techniques which will be possible to suit the specific local conditions and communities. a) Modified cropping patterns, improved nutrient supply and nutrient management strategies adjusted to available water resources, land leveling and soil improvement may all help in times of drought. As far as crop is concern it should have the tolerance to drought, should be efficient in utilizing the available water and deplete it more slowly. b) In the case of flooding, proper seed and seedbed management practices, direct seeding and optimal fertilizer use can help to have taller, healthier, less flood-susceptible plants that also recover better after flood exposure. c) Salinity can be managed by improving water harvesting, water management and appropriate choice of cropping patterns. Infrastructure can also be developed to improve drainage and yet restrict intrusion of saline water, thereby reducing the impact of salinity. 30
d) Heavy metal pollution has been a matter of grave concern. Efforts have been mainly restricted to phytoremediation of soils using plant species with high metal uptake capacity e.g. Brassica species. e) A number of studies have showed that Si alleviates physical stresses, including radiation, low and high temperature, wind, salinity, drought and waterlogging, low and high light and so on. Silicon seems to protect plants from radiation injury. Furthermore, when the plant was supplied with Si after radiation treatment, the growth recovery was faster compared to that of the plants without Si supply. Silicon can alleviate water stress by decreasing transpiration. There has been a considerable amount of work on the effects of Si under chemical stresses including nutrient imbalance, metal toxicity, salinity and so on. Silicon deposited on the stems and leaf blades prevents lodging and mutual shading. f) Rescheduling of Crop Calendars: Global temperature increase and altered rainfall patterns may result in shrinking of crop growing seasons with intense problems of early insect infestations. As such certain effective cultural practices like crop rotation and planting dates will be less or not effective in controlling crop pests with changed climate. Hence there is need to change the crop calendars according to the changing crop environment. g) Crop breeders now need to urgently turn their attention to the introduction of new varieties resilient to abiotic extreme stresses and considering late onset and/or shorter duration of winter, delaying and shortening the growing seasons. The large majority of new crop varieties released have been bred for improved resistance to pests and diseases, yet it is claimed that abiotic stress is the primary cause of crop loss, reducing average yields of most major crops by more than 50%. Breeding programmes must develop crop-specific and region-specific strategies so that the products are relevant to problems and conditions in next 10–15 years’ time. h) Genetic modification of crops is a controversial issue. Some aspects of genetic modification that have potential to improve abiotic stress tolerance in crops may be the option in the near future. Although several genes that can improve the abiotic tolerance of crops have already been identified, progress in the commercialization of the traits controlled by these genes has been slow. Identification and utilization of genes involved in the tolerance mechanisms for production of cultivars with better resistance to abiotic stresses is imperative for crop improvement. i) Increased need for consolidating collections of wild species, including crop wild relatives, due to increased likelihood of extinction for narrowly adapted and endemic species. Novel and increased demands on germplasm in genebanks for adapting agriculture to climate change, including the need to screening for different characters.
Conclusion Sustainability is the utmost concern in agriculture in these changing environmental conditions. It is the era for the survival of the fittest. The crops have to evolve through natural selection or by human interventions to survive extreme climates. Many challenges can be met upto some extent by understanding the mechanisms involved in crops responses to various abiotic stresses in the environment and modifying the current cropping pattern, through balance nutrient management and through efficient water utilization.
References and further reading Cramer GR, Urano K, Delrot S, Pezzotti M, Shinozaki K, 2011. Effects of abiotic stress on plants: a systems biology perspective. BMC Plant Biology 11: 163. Ma JF, 2004. Role of silicon in enhancing the resistance of plants to biotic and abiotic stresses. Soil Science and Plant Nutrition 50: 11-18. Schmitz G, Schütte G, 2000. Plants Resistant Against Abiotic Stress. FSP Biogum, University of Hamburg, Research Center for Biotechnology, Society and the Environment, Ohnhorst. 18, 22609 Hamburg. 31
Effect of climate change on rice production in India with special reference to North-East Hill Region Ch. Roben Singh Introduction Rice (Oryza Sativa L.) is the most important food crop of the developing world and the staple food for more than 60% of the Indian population. India needs to produce 120 million tons by 2030 to feed its one and a half billion plus population by then. Rice is the principal food grain crop of the North Eastern hilly region occupying 3.51 million hectares which accounts for more than 80% of the total cultivated area of the region and 7.8% of the total rice area in India while its share in national rice production is only 5.9%. The total rice production of NEH region is estimated to be around 18 lakh tones with an average productivity of 1.78 t ha-1, which is much below the national average of 2.18 t ha-1. Being the secondary centre of origin of rice, the NEH region is considered to be one of the hot pockets of rice genetic resources in the world and a potential rice-growing region with extremely diverse rice growing conditions as compared to other parts of the country. Jhuming (shifting cultivation) is still practiced in an area of about 0.88 m ha in the North Eastern Hill Region and occupies majority of the area under jhum. The rice productivity under jhum is less than a tone hectare-1. However, NEH region is lagging much behind the other advanced states as far as the production and productivity of rice are concerned. The reason for low rice productivity is the non adoption of location specific high yielding varieties and improved production technology. While trying for enhancing productivity in NEH Region, importance should be given on resource conservation and climate resilience for sustainability. Increased occurrence of extreme events like drought, heavy rainfall, floods, frost, etc. as a result of climate change of the Region needs to be considered.
Climate change and general conditions of climate of North-East Hill region Climate change is a change in the statistical distribution of weather patterns. It may be referred as change in average weather conditions, or in the time variation of weather around longer-term average conditions. Climate change is caused by factors such as biotic processes, variations in solar radiation received by earth and volcanic eruption. Certain human activities have also been identified as significant causes of recent climate change, often referred to as "global warming.” Changes in temperature and precipitation would affect crop production and make differences in temperature, soil moisture, soil pH, etc. requirements for crop growth (Lee, 2009). The climate of NEH region varies from near tropical in the plains of Tripura and South Mizoram to near alpine in the northern Sikkim and Arunachal Pradesh. The greater part of the region has subtropical climate. The average annual minimum and maximum rainfall in the region is estimated to be 1637 mm and 6317 mm respectively. The climate of Arunachal Pradesh is characterized by low temperature and extreme humidity due to the presence of extensive forests and high altitude. The climate of Meghalaya is characterized by coolness and humidity. In Mizoram, the average maximum and minimum temperature are 30°C and 12°C respectively with an average rainfall of 1660 mm. The climate of the hilly region of Manipur abutting Nagaland is same as the climate of Nagaland which is mainly sub-tropical and temperate. In Sikkim, the extreme variations in elevations account for extremely varied climatic condition.
Present status of rice production and productivity in NEH Region Rice is the most important cereal crop of the North Eastern Hill Region covering an area of about 8.91 lakh hectares producing about 18.00 lakh MT of rice with an average productivity of 1.78 t ha-1 which is below the national average of 2.18 t ha-1 (average from 2006-07 to 2010-11). 32
The rice area of NEH Region to the total area of the country is only about 2.04 % with a rice production of about 1.90 % to the total rice production of the country. The present deficit in rice productivity of NEH Region from the national average is about 18.35 %. The area, production and productivity of rice in NEH states for the year 2006-07 to 2010-11 are presented in Table 1. The average area, production, productivity, requirement, excess/deficit and % excess/deficit of NEH states from the year 2006-07 to 2010-11 are presented in Table 2. Table 1. Area production and productivity of r ice in NEH states for the year 2006-07 to 2010-11 State 2006-07 2007-08 2008-09 2009-10 2010-11 Mean (5 years) Arunachal A 1.220 2.240 1.268 1.215 1.216 1.232 Pradesh P 1.460 1.581 1.639 2.158 2.340 1.836 Y 1195 1275 1293 1776 1925 1493 Manipur A 1.660 1.661 1.684 1.694 2.127 1.765 P 3.860 4.062 3.970 3.199 5.217 4.062 Y 2322 2446 2357 1888 2453 2293 Meghalaya A 1.050 1.064 1.081 1.082 1.083 1.072 P 2.000 2.000 2.039 2.067 2.070 2.035 Y 1916 1880 1886 1910 1911 1901 Mizoram A 0.530 0.546 0.520 0.472 0.407 0.495 P 0.300 0.157 0.460 0.444 0.472 0.367 Y 559 288 885 941 1160 767 Nagaland A 1.650 1.725 1.731 1.686 1.814 1.721 P 2.640 2.906 3.451 2.043 3.814 3.043 Y 1600 1685 1994 1425 2103 1761 Sikkim A 0.150 0.140 0.147 0.130 0.121 0.138 P 0.220 0.229 0.217 0.243 0.210 0.224 Y 1433 1636 1476 1869 1736 1630 Tripura A 2.510 2.372 2.425 2.456 2.645 2.482 P 6.210 6.246 6.271 6.401 7.024 6.430 Y 2472 2633 2586 2606 2656 2591 All India A 438.136 439.144 455.374 419.185 428.625 436.093 P 933.553 966.929 991.824 890.931 959.797 948.607 Y 2131 2202 2178 2125 2239 2175 N.B.: A= Area in lakh hectare, P= Production in lakh tones and Y = Productivity in kg ha-1. Source: Directorate of Rice Development, Ministry of Agriculture, Govt. of India. Table 2. Average area, production, productivity, requirement, excess/deficit and % excess/deficit of NEH states from the year 2006-07 to 2010-11 States Area Production Producti Requirement Excess Excess (in lakh (in lakh vity (kg (in lakh MT) (+)/Defecit (+)/Defecit ha) tonnes) ha-1) (-) (in lakh MT) (-) % Arunachal 1.232 1.836 1493 2.143 (-)0.307 (-)16.72 pradesh Manipur 1.765 4.062 2293 4.219 (-)0.157 (-)3.87 Meghalaya 1.072 2.035 1901 4.594 (-)2.559 (-)125.75 Mizoram 0.495 0.367 767 1.691 (-)1.324 (-)360.76 Nagaland 1.721 3.043 1761 3.070 (-)0.027 (-)0.89 Sikkim 0.138 0.224 1630 0.942 (-)0.718 (-)320.54 Tripura 2.482 6.430 2591 5.690 (+)0.740 (+)11.51 NEH states 8.905 17.997 1776 22.349 (-)4.352 (-)24.18 Source: Directorate of Rice Development, Ministry of Agriculture, Govt. of India. Per capita consumption of rice: 155 kg person-1year-1 (www.rice.ws), Population: As per 2011 census. 33
The average rice productivity in the NEH states varies from 767 kg ha-1 in Mizoram to 2591 kg ha-1 in Tripura with a total rice of deficit of about 4.35 lakh metric tonnes. To be self sufficient in rice for the NEH states, rice production is to be increased by 24.2% from the present level of production. As the availability of land area for rice cultivation in NEH Region has become a limiting factor, increasing the level of productivity wherever possible by adopting the best available rice production technology to meet the ever increasing demand of rice has now become a great concern for NEH Region.
Major climate parameters for rice production and their possible effects Rice can be cultivated under varied climatic and soil conditions. For normal growth, a pH range of 5.0-8.0 is suitable. Important major climate parameters and their possible effect on rice production are discussed here under: (a) Temperature on rice productivity: Rice being a tropical and sub-tropical plant requires a fairly high temperature, ranging from 20° to 40°C. The optimum temperature of 30°C during day time and 20°C during night time seems to be more favorable for the development and growth of rice crop. Rice cultivation is conditioned by temperature at the different phases of growth. The critical mean temperature for flowering and fertilization ranges from 16 to 20°C, whereas, during ripening, the range is from 18 to 32°C. Temperature beyond 35°C affects grain filling. Rice is sensitive to high temperatures during critical stages such as flowering and seed development. Rice production can be dramatically affected by temperature. Traditionally, cool temperatures have been more limiting for rice production than warm temperatures. However, rice plants also respond to high temperatures. Thus, for tropical areas, increased temperature by itself could lead to reduction in grain yield. With the increase in daily maximum temperature averaged over flowering period above about 36°C, rice yield generally declined because of spikelet sterility induced by high temperatures. Importantly, elevated CO2 increases spikelet susceptibility to hightemperature damage (Kim et al., 1996). It has been suggested that indica spp. are more tolerant to higher temperatures than japonica spp although heat- tolerant genotypes have been found in both subspecies. Mathauda et al. (2000) showed the effect of temperature increase on the projection of climate change over rice crop. The increase of temperature will decrease the life span, grain yield, maximum leaf area index, biomass, and straw yield of the rice. High night-time temperature have been shown to have a greater negative effect on rice yields with a 1°C increase above critical temperature (>24°C) leading to 10% reduction in both grain yield and biomass. High day - time temperature in some tropical and subtropical rice growing regions are already close to the optimum levels. An increase in intensity and frequency of heat waves coinciding with sensitive reproductive stage can result in serious damage to rice production (Stigter and Winarto, 2013). (b) Solar radiation, Photosynthesis and respiration: The yield of rice is influenced by the solar radiation particularly during the last 35 to 45 days of its ripening period. The effect of solar radiation is more profound where water, temperature and nitrogenous nutrients are not limiting factors. Bright sunshine with low temperature during ripening period of the crop helps in the development of carbohydrates in the grains. Solar radiation is essential for photosynthetic activity. As such, the growth, development and yield of rice plants are affected by the level of solar radiation. Rice yields are closely correlated to the solar radiation during the reproductive and ripening phases of the rice plants. Therefore, the rice growing season varies in different parts of the country depending upon temperature, rainfall, soil types, water availability and other climatic conditions. The rate of photosynthesis does not increase with higher temperatures for all plants. Plants which grow in colder climates have an optimum rate of photosynthesis at low temperatures. Therefore, different types of plants have optimum temperatures for photosynthesis. However, for photosynthesis at temperatures above 40°C the rate slows down. This is because the enzymes involved in the chemical reactions of photosynthesis are temperature sensitive and destroyed at 34
higher temperatures. Carbon dioxide is used to make sugar in the photosynthetic reaction. An increase in the concentration of carbon dioxide gives an increase in the rate of photosynthesis. The rate of photosynthesis increases linearly with increasing carbon dioxide concentration (from point A to B on the graph). Gradually the rate falls of and at a certain carbon dioxide concentration the rate of photosynthesis stays constant (from point B to C on the graph). Here a rise in carbon dioxide levels has no affect on the rate of photosynthesis as the other factors such as light intensity become limiting. (c) Rainfall, humidity and wind velocity: Rainfall is the most important weather element for successful cultivation of rice. The distribution of rainfall in different regions is greatly influenced by the physical features of the terrain, the situation of the mountains and plateau. Rice crop requires about 1400-1800 mm water. Therefore, if this much rain occurs during crop season with well distribution will be sufficient for rice crop. When rice fields experience heavy rainfall, freshly seeded fields tend to have poor distribution, germination, and emergence. Direct seeded fields affected by heavy rainfall have poor plant stand, especially if wet direct seeded. Heavy rainfall during planting or crop establishment is becoming an increasingly important problem as wet direct seeding. Because of the nature of the problem it tends to be seasonal and cannot really be reliably predicted. When it occurs, fields need to be re-ploughed and re-seeded. Relative humidity is the ratio of actual water vapour content to the saturated water vapour content at a given temperature and pressure expressed in percentage (%). Relative humidity (RH) directly influences the water relations of plant and indirectly affects leaf growth, photosynthesis, pollination, occurrence of diseases and finally economic yield. The dryness of the atmosphere as represented by saturation deficit (100-RH) reduces dry matter production through stomatal control and leaf water potential. Further, the incidence of insect pests and diseases is high under high humid conditions. Moist humid weather during vegetative growth and dry sunny weather during ripening is most desirable. A relative humidity of 60-80% is said to be optimum. Winds may affect growth and production of rice plants. Winds at high speeds during the typhoons are very detrimental to the growth and production of rice plants, especially when they occur during the flowering and ripening phases of rice. Gentle wind is the best for rice cultivation because the supply of CO2 and its utilization is regulated to the maximum.
Conclusion From the above consideration, it appears that rice productivity, in general is dependent on various climate parameters. The optimum climate parameters are being changed due to global warming resulted from climate change. It is reported that rice productivity may be reduced by about 10 % with the rise of 1 degree Celsius in the night time. Similar situations may also be appeared if the other optimum climatic parameters for rice production are changed due to climate change.
References and further reading Kim HY, Horie T, Nakagawa H, Wada K, 1996. Effects of elevated CO2 concentration and high temperature on growth and yield of rice. Japanese Journal of Crop Science 65, 644–651 Lee H, 2009. The impact of climate change on global food supply and demand, food prices, and land use. Paddy and Water Environment 7: 321–33. Mathauda SS, Mavi HS, Bhangoo BS, Dhaliwal BK, 2000. Impact of projected climate change on rice production in Punjab (India). Journal of Tropical Ecology 41: 95–98. Stigter K, Yunita W, 2013. Rice and climate change: Adaptation or mitigation? Facts for policy designs. INSAM. International Society for Agricultural Meteorology September 18, 2013. 35
Soil and water conservation through mulching Z. James Kikon Introduction Land, water and vegetation are precious natural resources and the source of human sustenance and security. Since economic stability and scientific use of the land and water resources are inseparable, judicious planning of these resources is essential for sustaining productivity and ensuring sustainable soil, healthy environment and life support system of our planet. The magnitude of the problems associated with conservation of these resources need to be addressed urgently. The main aim of soil and water conservation is to minimize soil and water losses for sustainable productivity through scientific approach without hampering the system. India, being chiefly an agrarian economy, should have a good respect towards conservation strategies especially for soil and water as it is suffering from a great stress because of our carelessness. The soil and water conservation measures fall into two categories viz. agronomic and mechanical protection measure which is the need of the hour. Out of its many approaches, one urgent requirement is to restore soil health and conserve soil moisture through the age old practice of mulching. The word mulch has probably derived from the German word “molsch” meaning soft to decay, which apparently referred to the gardener’s use of straw and leaves as a spread over the ground as mulch. Mulching is an important agronomic practice that not only prevents soil erosion by dissipating the kinetic energy of rain drops thereby reducing the deterioration of soil by ways of preventing the runoff and soil loss but also facilitates infiltration, reduces evaporation, minimizes the weed infestation and improves soil structure. Thus it facilitates more retention of soil moisture and helps in control of temperature fluctuations, improves physical, chemical and biological properties of soil as it adds nutrient to the soil which ultimately enhances the growth and yields of crops.
Classification of mulch Mulches can be classified as organic and inorganic mulches on the basis of kind of material used for mulching.
(A) Organic mulch Organic mulch is made up of natural substance such as bark, wood chips, pine needles, dry grasses, paddy straw, dry leaves, saw dust, grass clipping, etc. However, organic mulch also attracts insects, slugs and the cutworms that eat them. They get decomposed within a short period of time thus requiring frequent replacements. Types of Organic mulches: a) Grass Clipping: This is one of the most abundantly and easily available mulch materials across the country. It provides nitrogen to the soil, if incorporated fresh. However, application of green grass in rainy season may result into the development of its own root system which will be detrimental to plant growth. Therefore, use of dry grass as mulch material is suggested. b) Straw: Paddy and wheat straw are the commonest mulching materials used for fruit and vegetable production. Though straw is poor in nutrient content, but once decomposed, makes the soil more fertile. Among organic mulching materials, straw has a longer life in comparison to other mulches (grasses, leaves and leaf mould). c) Newspaper: Newspaper mulching helps to control weeds. One to two cm thick sheet of newspaper should be used and edges should be fastened with materials like pebbles, gravels, etc. The application of newspaper mulch should be avoided on a windy day. 36
d) Dry leaves: Leaves, an easily available material, are good for mulching. Though leaves are good for protecting dormant plants during winter by keeping them warm and dry but due to light weight they may be blown away even by light wind. To counter this problem, it requires anchoring which can be done with stones, chipped bark and covering with net or some form of sheet. e) Bark clippings: These are good mulch materials as they are long lasting and allow proper aeration to the soil underneath. Hardwood bark clippings contain more nutrients than softwood but bark clippings are not easily and abundantly available, and some bark products may cause phytotoxicity. f) Saw dust: Saw dust, obtained during finishing operation of wood, is very poor in nutritive value as it contains only half the nutrients of straw. It decomposes slowly. Being acidic in nature, it should not be used in acidic soils. g) Compost: The compost is one of the best mulch materials. It increases microbial population, improves the soil structure and provides nutrients. It is the excellent material for improving the health of soil. Benefits of Organic Mulching: Mulch reflects a lot of the sun that otherwise heats the soil. This keeps the soil cooler and helps prevent evaporation. This is especially important in hot, dry climates. When the soil is covered in mulch, weeds do not grow under it as they do not get the light they need to grow. Mulches prevent soil erosion, as the wind or running water does not directly come in its contact and does not blow or wash it away. Mulches spread over soil, slow down rainwater run-off, and increase the amount of water that soaks into the soil. More water in the soil means more water for the crops. Organic mulches also improve the condition of the soil. As these mulches slowly decompose, they provide organic matter which helps keep the soil loose. These organic matters become food for the beneficial earthworms and other soil micro-organisms in the soil and create a very good porous soil. This improves root growth, increases the infiltration of water, and also improves the water-holding capacity of the soil. Decaying organic matter also becomes a source of plant nutrients. Maintains a more even soil temperature. Keeps a feet clean, allowing access to field even when wet. Limitation of Organic Mulching: Mulches can keep the soil too moist, restricting oxygen in the root zone on poorly drained soils. If mulch is applied close to or in contact with the stem, trapped moisture creates an environment conducive to development of diseases and pests. Many organic types of mulches also encourage and provide refuge or breeding locations for snails, slugs, mice, etc. that may attack the plants. Certain types of mulches such as hay and straw contain seeds that may become weeds.
(B) Inorganic mulch The use of inorganic materials such as gravels, pebbles, crushed stone and plastic films for mulching are known as inorganic mulch. Types of inorganic mulch: a) Gravel, pebbles and crushed stones: These materials are used for perennial crops. Small rock layer of 3-4 cm provides good weed control. But they reflect solar radiation and can create a very hot soil environment during summer. b) Plastic mulch: The use of both, black and transparent films for mulching is termed as plastic mulch. Advancement in plastic chemistry has resulted in development of films with optical properties that are ideal for a specific crop in a given location. These are two types: (i) photodegradable plastic mulch: This type of plastic mulch film gets destroyed by sun light in a shorter period and (ii) bio-degradable plastic mulch: This type of plastic mulch film is easily degraded in the soil over a period of time. 37
Types of plastic mulch based on colors of film: Soil environment can be managed precisely by a proper selection of plastic mulch composition, colour and thickness. Films are available in variety of colors including black, transparent, white, silver, blue, red, etc. But the selection of the colour of plastic mulch film depends on specific targets. Generally, the following types of plastic mulch films are in use: (i) Black plastic film: The black plastic film does not allow sunlight to pass through the soil thus photosynthesis does not take place in soil in absence of sunlight below the film. Hence it arrests weed growth completely. It helps in conserving moisture, controlling weed. However, it may increase the soil temperature. (ii) Clear or Transparent film: The film will allow the sunlight to pass through for which weeds may grow. However, herbicides coating in the inner side will check the weed growth. These films are best suited for soil solarization for disinfecting the soil from soil borne diseases and some weeds. (iii) Two-side colored film: Wavelength selective or photo-selective (also called two side colored) films are designed to absorb specific wavelengths of the solar radiation, which changes the spectrum of the sunlight passing through the films or being reflected back into the plant canopy. These light changes can have a marked effect on plant growth and development. Effects of some of the colored mulches are given below. a. Yellow/Black: Attracts certain insects thus, act as a trap for them. b. White/Black: Cools the soil. c. Silver/Black: Cools the soil though not to the extent of white or black film and repels some aphids and thrips. d. Red/ Black Partially transparent: They allow part of the radiation to pass through and warm the soil while reflecting the same back into plant canopy. It results in changes in plant vegetative growth, flower, development and metabolism to early fruiting and also yield increase in some fruits and vegetables. Advantages of Inorganic Mulching: Conserve soil moisture, reduce soil erosion, moderates soil temperature by insulating the soil surface, reduces incidence of disease by protecting above ground plant parts from splashes that carry soil borne diseases, weed control under mulch film, prevent leaching of fertilizer, provide conducive environment for plant growth, improves seed germination and productivity.
Methods in mulching (a) Surface mulching: Mulches are spread on soil surface to reduce evaporation and increase soil moisture. (b) Vertical mulching: It involves opening of trenches of 30 cm depth and 15 cm width across the slope at vertical interval of 30 cm. (c) Polythene mulching: Sheets of plastic are spread on the soil surface between the crop rows or around tree trunks. (d) Pebble mulching: Soil is covered with pebbles to prevent transfer of heat from atmosphere. (e) Dust mulching: Use of dust formed from intercultural operations to fill the cracks in the field to prevent evaporation. (f) Live vegetative barriers: Subabul and Glyricidia when used as live vegetative barriers on contour key lines not only serve as effective mulch when cut and spread on ground surface but also supply nitrogen to the extent of 25 to 30 kg ha-1, besides improving soil moisture status.
Improvement in yield by mulching The following examples showed an increase in yield of fruits (Table 1) and vegetables (Table 2) by the use of plastic mulch. 38
Table 1: Increase in yield of fruit crops through plastic mulching Crops Yield (t ha-1) Increase in yield (%) Unmulched Mulched Guava 18.36 23.12 25.93 Mango 4.93 7.16 45.23 Papaya 73.24 120.29 64.24 Ber 7.02 8.92 27.06 Pineapple 10.25 11.75 14.63 Banana 53.99 73.32 33.95 Litchi 111.0 125.0 12.16 Source: Practical Manual on Plastic Mulch, 2011. Table 2: Increase in yield of vegetable crops through plastic mulching Increase in yield (%) Crops Yield (t ha-1) Unmulched Mulched Broccoli 15.64 25.14 60.74 Cauliflower 18.58 25.02 34.66 Brinjal 36.73 47.06 28.12 Tomato 69.10 94.85 37.26 Okra 6.91 8.56 23.88 Bitter gourd 20.12 25.63 27.39 Chilli 16.79 19.71 17.39 cabbage 14.3 19.9 39.16 Source: Practical Manual on Plastic Mulch, 2011.
Conclusion In the present scenario of globalization and health consciousness, demand for food has increased world over. Excessive competition has not only compelled us to produce more but also to produce quality products for sustaining in the international market. Apart from using high yielding varieties and good agricultural practices, there is a need to utilize environmental/biological energy for higher production. Mulching is one such process that can help us in producing quality food in higher quantities. In the days to come, farmers will make use of this innovative technique that helps them conserve moisture, avoid weeds and improve soil health tremendously while producing more. This will also go a long way in achieving food security in a sustainable manner.
References and further reading Anonymous, 2009. Hand Book of Agriculture 2009. Indian Council of Agricultural Research, New Delhi- 110 012. Patil SS, Kelkar TS, Bhalerao SA, 2013. Mulching: A soil and water conservation practices. Research Journal of Agriculture and Forestry Sciences 1: 26-29. Practical Manual on Plastic Mulch, 2011. National Committee on Plasticulture Application in Horticultural. Department of Agriculture and Cooperation, Ministry of Agriculture, Government of India, New Delhi.
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Nutrients recycling through waste management-A key for climate proofing Agriculture Lahar Jyoti Bordoloi Introduction The detrimental effects of global climate change have started becoming increasingly evident in the North Eastern part of our country as well. Besides the commonly cited impacts viz., gradual rise in temperature and CO2 concentration, erratic pattern in distribution and intensity of rainfall, etc., there are many other manifestations of climate change which are impacting agricultural production silently but surely. A few among them includes: • Increasing occurrences of multiple nutrient deficiencies in both soil and plant system. • Anticipated enhancement of soil acidity. • Quantitative as well as qualitative changes in soil organic matter (SOM), a critical index of soil health. The faster decomposition of labile fractions of SOM, which is expected at higher temperatures, is bound to have multitudes of harmful impacts, including reduction in the water and nutrient holding capacities, decrease in the buffering capacity, degradation of soil aggregate stability, decline in soil biological activity etc., ultimately leading to progressive decline in soil health and crop productivity. Although dumped till recently under the (irresistible) concerns expressed in temperature and rainfall aberrations, serious attention is urgently warranted for ‘proper management of nutrients in both soil and plant system’, the poor status of which is one of the most important manifestations of climate change. Besides the decline in SOM quantity and quality, gradual reduction in use efficiency of applied nutrients, losses of nutrients from the soil system, occurrence of deficiencies of elements previously considered to be of lesser importance and overall decline in the productivity of agricultural production systems etc. have threatened to jeopardise our endeavour for food security and environmental safety.
Need of the hour A viable nutrient management plan bearing the following traits: • Consisting of nutrient sources generated using locally available resources. • Minimal/ judicious use of synthetic/ fertilizer nutrient sources to avoid wastage of both money and matter. • The plan should also provide to create enough opportunity for quality improvement/ upgradation of traditionally used nutrient sources viz., FYM, composts etc. • The programme should also offer to adequate opportunity for quality improvement/ upgradation of traditionally used nutrient sources viz., FYM, composts etc. • The strategy in question needs to be a unique amalgamation (combination) of locally available resources and technical knowhow seamlessly blended with synthetic inputs and improved technology as well. Once devised and implemented, the strategy must be able to achieve three objectives: (i) to replenish SOM pool, (ii) to supplement plant nutrients in a regulated manner ensuring its better use efficiency, and (iii) to supply as many nutrient elements from the source as possible, i.e. the nutrient source deployed must have a multi nutrient pool. It is their ability to meet the above 3 objectives that the relevance/ utility of waste recycling/ nutrient recycling has seen a renewed surge globally of late. This has rekindled scientific attention towards evolution, testing and standardization of improved methods of waste recycling. One such method of waste recycling bearing tremendous potential is the enriched composting/ phosphosulpho- nitro (PSN) composting. 40
PSN composts- what is it? It is the compost prepared from organic substrates (crop residue, weed biomass/ animal manures, etc.) fortified with the sources of phosphorus (rock phosphate/ single super phosphate), sulphur (elemental sulphur/ ZnSO4/ FeS2) and nitrogen (urea). The use of synthetic nutrient sources is kept at minimum and a selection of the substrate (s) could prefer based on the locally available composting materials.
Benefits of PSN composts The objective behind the genesis of phospho- sulpho- nitro compost (PSN compost) was to counter the menace of poor use efficiency of applied nutrients. PSN compost provides plant nutrients in a form moderately embedded in a carbon matrix of decomposed organic matter, thereby transmitting it with a nature of labile cum slow release plant nutrient source. Thus the PSN composts bear tremendous potential as an ideal nutrient source in NEH region soils marred with constraints such as very poor nutrient use efficiency owing to lighter texture causing severe leaching, rampant surface runoff and erosion. The nominal use of synthetic fertilizers in the preparation of this enriched compost is another feature of this technology, which can address the poor availability of synthetic nutrient sources in the region.
Major ingredients for preparation of PSN compost I. Substrates: These are the organic residues to be recycled. Mostly of 2 types(a) Crop residue viz., paddy straw, maize stover, groundnut and soybean stalks and (b) Weed biomass viz., Ambrossia artimisifolia, Eupatorium spp. and Ageratum conyzoides, Lantana camara etc. II. Animal manures: They are the organic sources of nutrients; may be of different types, viz., cow dung, poultry manure, pig manure, rabbit dung etc. III. Synthetic nutrient sources: Urea, Mussoorie rock phosphate, single super phosphate, elemental sulphur, zinc sulphate etc.
Benefits of substrate fortification in the PSN compost The overall impact of substrate fortification on production of PSN compost lies in substantial improvement in nutritive value of the end product, i.e. compost and significant reduction in time needed for composting due to the hastening of the decomposition process. Urea: • As a source of nitrogen it narrows down the C: N ratio of the substrate thereby facilitating its rapid decomposition. • Provides a labile source of nitrogen for the decomposer microbes at the initial stages of decomposition. • Boosts the nutritional status of the final product, i.e. compost. Mussoorie rock phosphate (MRP): • Inexpensive source for enriching the compost with P. • Acts as a P supplement to the decomposer microbes boosting their activity. • Plays a key role in governing the rate of decomposition. Time for compost preparation reported to be reciprocally proportional to the rate of MRP addition to the substrate. • The organic acids released by the dung/excreta inhabiting microorganisms cause rapid release of water soluble and citrate soluble P from the MRP making them usable by the whole lot of decomposers. • The status of water and citrate soluble P of the compost is improved manifolds.
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Elemental sulphur (S): • Hastening of the composting process due to addition of S source has not been established. But it definitely enhances nutritive value of compost. • The slurry is the most important constituent of PSN composts. Slurry is prepared by mixing of animal manure, soil and well rotten composts in the ratio of 1:1:0.5. Slurry has more than one important function in the preparation of PSN compost. They are:• Provides moisture to the dry substrates. • Ensures uniform distribution and blending of the mineral additives to each layer of the substrate. • Provides the seat for initialization of microbial activity in the compost pit.
Production protocol of PSN compost Substrates Succulent/ green
Naturally dry Shredding (10-15 cm size)
Mixing in 1:1 ratio and weighing
Preparation of slurry (Livestock dung/excreta+ Soil+ well rotten compost at 1:1:0.5 ratio Mud plastering of walls and bottom of the pit Filling the pit in layers (Each layer approx. 20 cm) thick) Sprinkling of slurry N @ 0.5% as urea P2O5 @1.5% as mussoorie rock phosphate Elemental S @ 0.5% Addition of mineral additives and mixing with the substrate layer Moisten the substrate with water sufficiently (70%) Continue filling the pit with substrate layers as above until a height of 1ft above ground surface is reached Mud plastering of pit top making a dome shape Materials allowed to decompose for three and half months with turning and watering (if necessary) at 20 days interval 42
Major steps in preparation of PSN compost: Step-I: Shredding and mixing of substrate Substrates are chopped to approx. 10cm length; dry and succulent substrates are mixed together in equal parts. Shredding of substrates enhances surface area for better microbial activity. Mixing of dry and green substrates in equal proportion helps to bring down the C: N ratio of the desired range (30:1). Step II: Pit digging Pits of 3m (L) x 2m (B) x 1m (D) dimensions are dug in a location of the farm which is free from water stagnation. With this dimension, each pit can accommodate approximately 3 quintals of mixed substrate. Step III: Plastering the pit Before filling the pit with substrates, the inner sides and bottom of the pit are plastered using the slurry. Plastering with slurry creates a nearly impervious layer that checks seepage loss of nutrients and prevents entry of water from outside. The slurry at the pit bottom also provides an ideal site for microbial activity. Step IV: Pit filling Approximately 20 cm thick layer of the substrate is placed uniformly on the pit bottom. The slurry is then sprinkled over the substrate layer in sufficient quantity to ensure a coating of the whole substrate with slurry. The slurry acts as a sticker that helps the mineral additives to adhere to the substrate. Immediately after sprinkling of slurry, mineral additives are given to the substrate layer. After adding mineral additives, another new layer of substrate is placed in the similar way. These steps are repeated in similar fashion till the pit gets filled up with substrate and reaches a height of 1ft above the ground floor. The materials inside the pit are moistened with water sufficiently (70% moisture content). Step V: Plastering of pit top After filling the pit, a dome shape is given to the substrates remaining above the ground level. The pit top is then plastered with a thick layer of the slurry. Care should be taken to maintain proper consistency of the slurry so that cracks do not develop easily on drying. Plastering is required: • To attained temperature rapidly inside the pit. • To act as a semi impervious layer restricting the entry of excess water and flies from outsides. • To ensure diffusion of oxygen to the underlying substrates in a contained way. Step VI: Turning and Moistening After every 20 days the pit cover is removed and materials inside are given a thorough turn. Moisture in the materials is also checked and maintained at 70% by addition of water if necessary. After turning and moistening, pit top is plastered again. • Turning ensures uniform distribution of temperature throughout the compost pile facilitating production of a homogenous end product. • Turning also helps maintain moisture uniformly throughout the compost pile. • Over- heating of huge compost heaps can be avoided through regular turning of the substrates. • Turning also facilitates proper aeration, which is required for the uninterrupted decomposition at a faster rate. Step VII: Judging the completion of composting As determined the maturity and stability indices are cumbersome, at farm level, completion of the composting process is judged based on some physical indicators. They are: • No more reduction in volume. • Conversion of the substrate to a dark brown to black coloured mass. • Absence of the pleasant smell, giving way to a soil- like musty odour. 43
• Little or no presence of substrate recognizable in original form. • Complete cooling down in the compost pile. No more heating upon wetting. • Production of a mass- friable and brittle when dry. Step VIII: Harvesting of compost Once composting process is completed, the compost is collected from the pit. Care is needed to avoid scraping of the pit-bottom-soil along with compost as the presence of foreign materials like soil deteriorates the quality of the compost. Step IX: Post harvest processing of compost After collection from the pit, compost is spread under a shade to remove excess moisture and unwanted materials like, stone, pebbles, plastics, metals etc. The final product should contain 3550% moisture. Compost dried under shade is sieved using 1 inch mesh to get a uniform size. The processed compost is then stored in a cool, dry place for future use.
Application methods of PSN compost Some common applications of PSN compost are listed below: • Broadcasting: Mostly used in field crops. • Placement in pit: Mostly in horticultural crops. • As potting mix: Mostly used for raising flowers and vegetables seedlings. • As mulch: A thick layer (3-4 inches) of PSN compost acts as excellent organic mulch. • As compost tea: Very rich in micronutrients, humic acids and growth promoters. Mostly used as a spray.
Nutritive value and nutrient supplying potential of PSN compost Nutritional variability in different types of compost (Table 1) and potential supply nutrients through composts under variable rates of application (Table 2) are as under: Table 1: Nutritional variability in different types of compost Types of compost pH C (%) N (%) C:N P (%) K (%) PSN- CDS a 7.2 26.2 2.5 10.48 4.4 1.3 PSN- PIMSb 7.1 29.8 2.8 10.64 4.6 1.6 PSN- POMSc 6.8 27.6 2.9 9.52 4.9 1.8 PSN- PSS d 6.8 38.8 1.9 20.42 4.1 1.1 6.6 42.7 0.8 53.38 0.3 0.4 FPe
of plant
S (%) 0.74 0.68 0.63 0.65 0.21
Table 2: Potential supply of plant nutrients through composts under variable rates of application Plant Types of compost & application rate (t ha-1) nutrients PSN-CDSa PSN-PIMSb PSN-POMSc PSN-PSSd FPe -1 (kg ha ) 2.5* 5.0** 2.5 5.0 2.5 5.0 2.5 5.0 2.5 5.0 N 62.5 125.0 70.0 140.0 72.5 145.0 47.5 95.0 20.0 40.0 P 110.0 220.0 115.0 230.0 122.5 245.0 102.5 205.0 7.5 15.0 K 32.5 65.0 40.0 80.0 45.5 91.0 27.5 55.0 10.0 20.0 S 18.5 37.0 17.0 34.0 15.8 31.5 16.3 32.5 5.3 10.6 a PSN compost with cow dung- soil slurry *Application rate of 2.5 t ha-1 b PSN compost with pig manure- soil slurry ** Application rate of 5.0 t ha-1 c PSN compost with poultry manure- soil slurry d PSN compost with plain soil slurry e Ordinary compost (Farmer’s practice)
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References and further reading Bujarbaruah KM, 2004. Organic Farming: Opportunities and Challenges in North Eastern Region of India. In: Souvenir (Nature), International Conference on Organic Food, pp. 13-24. California Compost Quality Council, 2001. Compost Maturity Index. Prepared by California Compost Quality Council (CCQC). 19375 Lake City Road, Nevada City, CA 95959. Cline WR, 2007. Global Warming and Agriculture: Impact Estimates by Country, Peterson Institute for International Economics, Washington DC, 2007. Deka RL et al., 2009. Impact of Climate Change on Agriculture. ISPRS Archives, XXXVIII-8/W3 Workshop Proceedings. Kumar M, 2010. North East India: soil and water management imperatives for food security in a changing climate. Current Science 101: 11-19.
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Water budgeting in hill farming of North Eastern region of India P. Chowdhury, Dibyendu Chatterjee and Bidyut C. Deka Introduction Water is one of the key resources of North Eastern region. North East is endowed with bounty of water resources accounting for about 40% of the total water resources in the country. The tentative assessment of this dynamic resource in the North East India is about 60 million hectaremeter. Unfortunately, this vast potential has not been exploited as yet. The region experiences a paradoxical hydro climatic environment and represents a typical hydrological entity in the world atlas. Endowed with huge water resources potential, it has also the worst water resource problems rendering untold sufferings to millions every year. Water and land resources are declining at a fast rate. To address these problems, judicious use of water, land, capital, labour etc are of prime concern especially in rainfed dominated North Eastern Indian hill agriculture. Water budgeting techniques have emerged as promising solutions to enhance efficiency, equity and economy of rainfed agriculture. Small and marginal farmers, up to 2ha land holdings are in a great distress due to increased urbanization, industrialization etc and have lost confidence in continuing this profession further. The developed water budgeting techniques are useful for this category of farmers to build confidence in crop planning, irrigation scheduling and water management under the existing trend of global climate change scenario.
Rainfall pattern in North East India The North Eastern Region is the highest rainfall zone of the country and enjoys typical monsoon climate with variants ranging from tropical to temperate conditions. The rapid changes in topography result in climatic changes within short distances. The foothill plains, sheltered valleys and the mountain ranges are however marked with climatic contrasts and as such any generalization regarding the climate of the whole region will be hardly apt for its micro zone. The rains are of long duration and occur mostly between March and October. During March and April the rainfall is sporadic but it is steady and heavy or very heavy during May and October. Annual rainfall in north eastern portion of Arunachal Pradesh, north west of Dihang and north east of Bomdila is about 4000 mm, but gets reduced in southern western districts. The rainfall increases in Khasi Jaintia and Garo hills (over 10,000 mm) but drop down in the north of Brahmaputra valley (about 2000 mm). The central parts of Meghalaya are famous for phenomenonaly high rainfall experience with average annual rainfall exceeding 2700 mm (Anonymous, 2004). The northern and adjoining central area is in the rain shadow region having rainfall varying from 4000 to 2000 mm. The Imphal, Lumding region which partly lies in the rain shadow of the Mikir hill range records lowest rainfall (1000 2000 mm). The distribution of rainfall in various North Eastern states is given in Table 1. Table 1 Distribution of monthly rainfall (mm) in North Eastern Region Month Assam Arunachal Manipur Meghalaya Mizoram Nagaland Tripura Pradesh Jan 18.4 26.5 9.7 0 7.5 24.6 10 Feb 38.4 117.5 416.7 16.6 18.5 50 51.2 Mar 81.5 139 168.8 199 65.5 102 290.4 Apr 212.6 229 213.4 238 84 119.9 116.3 May 237.6 234.5 268.4 299.8 88.5 117.6 199 Jun 484.3 484 418.8 193.8 64 342.8 192.4 Jul 446.8 336.7 225.3 158.3 441 202.3 238.6 Aug 395.9 133.5 297.9 361 157 143.4 243.8 Sep 317.1 213 104 356.5 157 79.5 84.7 Oct 144.1 181.6 34.8 342.8 55 99.2 110.6 46
Nov Dec Total
30.8 11.2 13 291.2 1 13 51.2 8.9 18.5 0.0 0.0 0.0 0.0 0.0 2416.4 2125 2170.8 2457 1139 1294.3 1588.2 Source: Annual Report (1993), I.C.A.R. Research Complex for N.E.H. Region, Umiam The rainfall is mostly associated with storms and is generally heavy with average number of days having 25 mm or more rainfall is over 100, except southern Meghalaya where there is an average of two days in every three days. Daily rainfall with a ten year return period ranges from 150 to 225 mm over most of the region and that over 500 mm can be expected once in a year (Sharma, 1996). The pre monsoon rainfall (March-May) accounts for 25% of annual rainfall while bulk of the rainfall (67%) occurs during Jun to September which constituted the monsoon season. The monsoon withdraws from the North East India almost abruptly in the last week of September or first week of October and post monsoon rainfall (October to December.) and winter monsoonal rainfall are scanty limiting the scope for agricultural activities during the rabi season (Satapathy and Dutta, 2002). The annual variations in rainfall are very wide from one place to another and its duration is most uncertain. The meamn monthly rainfall variation in different states of north eastern region is depicted below in Fig. 1.
Fig.1: Rainfall variation in different states of north eastern region
Water use efficiency/ water productivity in the small-scale agriculture Crop productivity is usually measured in ratio to inputs such as capital, fertilizer, energy and labour. The concept of crop productivity has shifted to water productivity with the idea to manage water resources. The concept of water productivity is a useful water management tool because it provides farmers with an insight into the quantity of water required to acquire minimum, optimal, and maximum crop yield (Bennett, 2003). Crop yield is a major output in water-productivity frameworks (Bastiaanssen et al., 2003). Water productivity, a concept expressing the value or benefit derived from the use of certain quantity of water, has been defined as the amount of output produced per unit of water involved in the production, or the value added to water in a given circumstance (Singh et al., 2006). Water productivity can be defined with respect to the different sectors of production involving water for example, crop production, fishery, forestry, domestic and industrial water use. Water productivity with respect to crop production is referred to as crop water productivity and is defined as the amount of crop produced per volume of water used (Igbadun et al., 2006). Water consumed includes green water (effective rainfall) for rain-fed agriculture, but for irrigated agriculture, both blue (diverted water from water systems to be used for irrigation) and green water is considered in assessing water productivity (Senzanje et al., 2005). Water productivity is a useful criterion used for decision making on crop production (Tyagi, 2003). 47
Increasing water productivity is a solution to scarce water resources and it covers several meanings. Firstly, it means that the output of a given crop per unit volume (m3) of water is raised. Secondly, it means that the economic productivity of irrigated agriculture can be increased by shifting to crops with higher benefit per unit volume (m3) of water applied (Molle, 2003). Improving water productivity will eventually ease the competition for scarce water resources, securing household food security, and preventing environmental degradation. Increasing productivity of water is particularly important in arid and semi-arid environments where water scarcity is very high (Molden et al., 2003). Increased water productivity in the irrigated agriculture provides the baseline for food security with lower water withdrawal leaving more water available to other users within the basin (Randolph et al., 2003). The unit of crop water productivity (CWP) in terms of seasonal crop consumptive use (Seasonal Water Used (SWU)) can calculated as: CWP(consumptive use)= ...........(1) Crop water Productivity can also be expressed in terms of Seasonal Water Applied (SWA), and can be calculated as follows: CWP(Water Applied) = Crop water productivity can also be defined in monetary terms, expressed in terms of economic return from crop produced per unit volume of water, with the unit expressed in equivalent of any currency (e.g. $ m-3) (Igbadun et al., 2006), and can be calculated as follows: CWP(Economic) = Where P = price of crop (price kg-1 crop yield) Crop water productivity can also be described as the grain yield per unit water evapo-transpired (Tuong et al., 2003; Azevedo et al., 2006). CWP(Evapotranspiration) = The concept of crop water productivity has remained a subject of interest to plant, soil and irrigation scientists for almost 100 years now. The other term used to express the concept of water productivity is water use efficiency. These two words are used interchangeably depending on the preferences of the user (Igbadun et al., 2006).
Water demand in North East India
The approximate demand for water in the region has been estimated to be 7.8 km3, 13.0 km3 and 19.2 km3 in 1995, 2010 and 2025, respectively. Major quantity of water is required for agriculture and it is expected that the demand for irrigation which is about 64% at present would be around 61.5% in 2012 and 59.9% of the total demand of water by 2025. The other demands for water are for domestic use, energy and industrial use. The present requirement of water for domestic, energy and industrial use is 12.8%, 9.05% and 1.3% of the total demand, which is expected to be 9.2%, 11.5% and 3.8% by 2010 and 8.8% and 4.1% by 2025, respectively.
Water resources in NE region The North Eastern region of India experiences excessive rainfall and high floods during monsoon months and also suffer from acute shortage of even drinking water in many areas due to lack of management. The basic issue underlying the water resources problems are recurring floods, drainage congestion, soil erosion, human influence on environment and so on and calls for its integrated use for drinking, irrigation, generation of hydropower, navigation, pisciculture, recreation etc. Since most of the areas in the North East region have been declared as restricted area, even the scholars have no access to elementary physiographic or geomorphological data to make proper inventory. Per capita fresh water availability in the Himalayan Region is evaluated to range from 48
1757 m3yr-1 in Indus, 1473 m3yr-1 in Ganga, 18417 m3yr-1 in Brahmaputra with an all India average of 2214 m3yr-1.
Water budget of North Eastern Hill region of India The region has 46% of the country’s valuable surface water resource. The surface water is distributed in important rivers, tributaries and natural reservoirs. The rivers of the region are fed by heavy precipitation and to a lesser extent by snow of Himalayan range. Most of the surface water is confined to the two important river systems- Brahmaputra and Barak. The state wise annual ET loss, recharge to ground water and surface runoff loss data has been worked out. The water budget of the North Eastern states is given in Table 2. Table 2: Annual Water budget of North Eastern Hill Region of India Item
Unit
km2 mm MCM mm % MCM Recharge mm to % ground MCM water Surface mm water % runoff MCM GA Average rainfall ET losses
Arnachal Pradesh 83740 2930 245358 905 31 75785 205 7 17168
Assam
Manipur Meghalaya Mizoram Nagaland Tripura
Total
78440 2336 2E+05 873 37 68478 234 10 18355
22330 1972 44035 864 43 18891 118 6 2635
22430 2253 50535 807 36 18101 113 5 2535
21080 2535 53438 976 39 20574 128 5 2698
16580 1986 32928 872 44 14458 99 5 1641
10490 2516 26393 857 34 8990 151 6 1584
255090 2493 635923 883 35.50 225277 183 7 46716
1820 62 152405
1229 53 96403
1008 51 22509
1313 59 29751
1431 56 30166
1015 51 16829
1508 60 15819
1426 57.20 363882
GA: geographical area, BCM: billion cubic meters
Water budgeting of hill agriculture of Nagaland Analysis based on the average rainfall data from 1998–2009 shown that Nagaland received the normal annual precipitation of about 1616.42 mm. The state receives about 26.80 BCM of rainfall, out of which about 12.87 BCM was lost as the evapotranspiration. Most of the rain water was drained into the streams as surface runoff and quick baseflow and some quantity of water gets stored in few farm ponds constructed on the hill terraces. However, due to high seepage rate (about 45-70 litre m-2 day-1), the water retention capacity of these small farm ponds reduced drastically. Recently, some technological interventions have been made for storing water in low-cost microrainwater harvesting structures (Jalkunds), baseflow harvesting structures, concrete storage tanks, constructing check dams on the perennial springs, rooftop rainwater harvesting structure etc. In Nagaland, onset date of South-West monsoon normally starts on 1st June and it normally ceases during 5th to 12th October. The average winter (January to February), pre-monsoon (March to May), monsoon (June to September), and post-monsoon (October to December) seasonal rainfall distribution patterns in Nagaland was 34.91, 326.89, 1077.90, and 176.72 mm, respectively. Analysis of 12 years weather data (1998-2009) on annual and monthly rainfall distribution and potential evapotranspiration (ETo) (Fig.1a and Fig. 1b) indicated that there was a decreasing trend in the total rainfall pattern over the years considering the drought years of 1998 (34.79% deficit than normal) and 2009 (40.11 % deficit than normal) and water surplus years of 2000 (37.51 % above normal), 2004 (11.27 % above normal) and 2007(27.23 % above normal).
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Fig. 1 (a) Annual and (b) monthly normal rainfall and evapotranspiration (ETo) distribution patterns in Nagaland The net annual water demand for Nagaland in 2001 was about 83.47 million cubic metres (MCM) excluding agriculture sector. Considering a constant decadal population growth rate of 64.53%, the net water demands for Nagaland (excluding agriculture sector) in 2011, 2021, 2031, 2041, and 2051 are projected to be about 137.34, 225.96, 371.78, 611.68, and 1006.40 MCM year-1, respectively. For prioritization of the water needs, water poverty mapping of an area was carried out depending on the physical availability of water resources, access to water for domestic and agricultural sectors, capacity of the stakeholder to manage water, the ways of water use in various sectors, and environmental integrity with respect to water and ecosystem goods and services from the flora and fauna. A case study on the water poverty mapping based on household surveys in Lampong Sheanghah village of Mon District showed that all the households fared very poorly in terms of most of the components of water poverty index (WPI), i.e., water use (0.15), water resource (0.38), water access (0.40), and capacity (0.40) with an overall value of 0.44. This revealed that “access to water resources” and ‘stakeholders’ capacity to manage water” were the two major factors contributing to water poverty in this area. Nagaland has a WPI value less than that of the Indian national average of 0.51.
Conclusion Water Budgeting is most essential phenomenon for ensuring optimum and most efficient use of water. This involves gaining an understanding of water availability, community’s existing needs and requirements of water, crop-planning based on water availability, optimizing irrigation, equitable sharing of excess water, and considered decisions on groundwater withdrawals. The Water-Budgeting exercise brings to light water availability within the village. Advance planning of Water budgeting could help in better irrigation scheduling and crop planning and making better crop decisions. This kind of integrated approach and exercises help the farming community to understand the implications of the different patterns of water use that are prevalent. By obtaining village level water availability data (from the rainfall and that obtained from the well data), the 50
people are able to assess the water available at their disposal for the coming months, plan the judicious uses of water and decide on the crops accordingly, after taking into consideration the needs of households and livestock.
Reference and further reading Annual Report, 2009-10, ICAR Research Complex for NEH Region, Umiam, Meghalaya Azevedo PV, Sousa IF, Da silva BB, Da Silva VPR, 2006. Water use efficiency of dwarf-green coconut (Cocos nucifera L.) orchards in northeast Brazil. Agricultural Water Management 84: 259-264. Bastiaanssen W, Ahmad MD, Tahir Z, 2003. Upscaling water productivity in irrigated agriculture using remote sensing and GIS technologies, International Water Management Institute, Colombo, Sri Lanka. Bennett J, 2003. Opportunities for increasing water productivity of CGIAR crops through plant breeding and molecular biology, International Rice Research Institute, Manila, Philippines. Igbadun HE, Mahoo HF, Tarimo AKPR, Salim BA, 2006. Crop water productivity of an irrigated maize crop in Mkoji sub-catchment of the Great Ruaha river basin, Tanzania. Agricultural Water Management 85: 141-150. Molden D, Kijne JW, Barker R, 2003. Improving water productivity in agriculture: Editor’s overview, International Water Management Institute, Colombo, Sri Lanka. Molle F, 2003. Reform of the Thai irrigation sector: Is there scope for increasing water productivity? International Water Management Institute, Colombo, Sri Lanka. Ngachan SV, 2012. Rain water harvesting and its diversified uses for sustainable livelihood support in NEH region of India Director ICAR Research Complex for NEH Region, Umiam-793 103, Meghalaya. Pali et al., 2012. Water harvesting based sustainable farming in Chhattisgarh, IGKV/Pub./T.bl/ 2012/03. Randolph B, Dawe D, 2003. Economics of Water Productivity in Managing Water for Agriculture, International Water Management Institute, Colombo, Sri Lanka Rasiuba TC, 2007. Water budget, water use efficiency in agriculture in olifants catchment. A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Science in Engineering, Johannesburg. Senzanje A, Chimunhu T, Zirebwa J, 2005. Assessment of water productivity trends for parastatal agricultural operations-case of Middle Sabi Estate, Zimbabwe. Physics and Chemistry of the Earth 30: 767-771. Singh R, Van Dam JC, Feddes RA, 2006. Water productivity analysis of irrigated crops in Sirsa district, India, Agricultural Water Management 82: 253–278. Tuong TP, Bouman BAM, 2003. Rice production in water-scarce environments, International Rice Research Institute, Manila, Philippines. Tyagi NK, 2003. Managing saline and alkaline water for higher productivity, Central Soil Salinity Research Institute, Haryana, India. www.kiran.nic.in
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Livestock production in a changing climate: Impacts and mitigation Manas Kumar Patra and Yhuntilo Kent Introduction Climate change is a long-term change in the distribution of weather patterns over periods of time. It may be a change in the average weather conditions or a change in the distribution of weather events with respect to an average, for example, greater or fewer extreme weather events, rising average surface temperature, increase in sea level and decrease in ice extent. Climate change may be limited to a specific region, or may occur across the whole Earth. With the advancement in civilization and to meet the requirement of increasing global population, human and industrial activities have already disrupted and change the nature force which is very much needed for maintaining the climatic state. Since the industrial revolution, atmospheric CO2 levels have elevated by about 30 percent due to increased combustion of fossil fuels (IPCC, 1996). The likely impacts of such changes in CO2 levels on global climate are widespread. Climate change, whether the result of anthropogenic activities or not, will impact agricultural production throughout the world which will affect directly or indirectly to animal production. The livestock production system is sensitive to climate change and at the same time it a contributor to the phenomenon, climate change has the potential to be an increasingly formidable challenge to the growth of the livestock sector in India. This sector holds a very significant part to play in the economic advancement of the nation as it contributes over one-fourth (26%) to the agricultural GDP and provides employment to 18 million people in principal or subsidiary status. Responding to the challenge of climate change requires formulation of appropriate adaptation and mitigation options for the sector.
Contribution of livestock to climate change The animal production system, which is vulnerable to climate change, is itself a large contributor to global warming through emissions of methane and nitrous oxide. There are two sources of GHG emissions from livestock: (a) From the digestive process: Methane is produced in herbivores as a by-product of ‘enteric fermentation’ a digestive process by which carbohydrates are broken down by micro-organisms into simple molecules for absorption into the bloodstream. (b) From animal wastes: Animal wastes contain organic compounds such as carbohydrates and proteins. During the decomposition process of livestock wastes under moist, oxygen free (anaerobic) environments, the anaerobic bacteria transform the carbon to methane. Animal wastes also contain nitrogen in the form of various complex compounds. The microbial processes of nitrification and denitrification form nitrous oxide which is also emitted to the atmosphere.
Impact of climate change on livestock production The climate change influences the growth and physiology of production animals by various ways. All the major components of the production cycle likes, water, feed and fodder, biodiversity and genetic makeup, livestock health, and disease and pest prevalence are affected by one or other way (Thornton et al., 2008). (a) Water: • Water scarcity is increasing at an accelerated rate and affects between 1 and 2 billion people. • Climate change will have a substantial effect on global water availability in the near future.
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Depletions of drinking water sources for livestock and irrigation water for agricultural operation have a bearing on livestock feed production systems and pasture yield. (b) Feed and Fodder: • Land use and system changes: As climate changes and becomes more variable, niches for different species alter. This may modify animal diets will lead to compromise the ability of smallholders to manage feed deficits. • Changes in the primary productivity of crops, forage and rangeland: Effects will depend significantly on location, system and species. In C4 species, a rise in temperature to 3035° C may increase the productivity of crops, fodder and pastures. In C3 plants, rising temperature has a similar effect, but increases in CO2 levels will have a positive impact on the productivity of these crops. • For food/feed crops, harvest index will change the availability of energy which can be metabolized for dry season feeding. In semi-arid rangelands where the growing season is likely to contract, productivity is expected to decrease. • Changes in species composition: As temperature and CO2 levels change, optimal growth ranges for different species will also change; species alter their competition dynamics, and the composition of mixed grasslands changes. For example, higher CO2 levels will affect the proportion of browse species. They are expected to expand as a result of increased growth and competition between each other. Legume species will also benefit from CO2 increases and in tropical grasslands the mix between legumes and grasses could be altered. • Changes in climate would affect the quality and quantity of forage produced. The impact of climate change on pastures and rangelands may include deterioration of pasture quality towards poorer quality subtropical. • Quality of plant material: Rising temperatures increase lignifications of plant tissues and thus reduce the digestibility and the rates of degradation of plant species. (c) Biodiversity (genetics and breeding of livestock): • In some places, there will be acceleration in the loss of the genetic and cultural diversity already occurring in agriculture as a result of globalization. This loss will also be evident in crops and domestic animals. • Rise in global temperature about 2.5°C would determine major losses; between 20 and 30% of all plant and animal species assessed could face a high risk of extinction. • Ecosystems and species display a wide range of vulnerabilities to climate change, depending on the imminence of exposure to ecosystem-specific critical thresholds, but assessments of the effects of CO2 fertilization and other processes are inconclusive. (d) Livestock (and human) nutrition: • Voluntary feed intake (VFI) is the primary factor influencing the production capacity of livestock, thus, accurate prediction of the feed consumption of livestock under heat stress is a precursor to accurate assessment of changes in production in the context of climate change. • Animal’s breed, age, and sex affect its maintenance energy requirements and therefore it’s VFI. Management practices, like bunk location and size and feeding frequency also affect feeding behaviour. • The health of an animal will affect VFI, as diseased animals will reduce intake. • Water restriction also leads to reduced VFI. • Indigenous breeds could be lost as a result of the impact of climate change and disease epidemics. Biodiversity loss has global health implications and many of the anticipated health risks driven by climate change will be attributed to a loss of Genetic diversity. 53
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The consequent reduction in livestock production may have an effect on the food security and incomes of smallholders. Interactions between primary productivity and quality of grasslands will require modifications in the management of grazing systems to achieve production objectives. (e) Incidences of livestock diseases and pests prevalence: • Climatic restrictions on vectors, environmental habitats and disease causing agents are important for keeping many animal diseases in check. • However, alterations of temperature and precipitation regimes may result in a spread of disease and parasites into new regions or produce an increase in the incidence of disease, which, in turn, would reduce animal productivity and possibly increase animal mortality (Baker et al., 1998). (f) Direct effects of weather and extreme events on animal health, growth and reproduction: • Direct effects of climate change involve heat exchanges between the animal and the surrounding environment that are related to radiation, temperature, humidity and wind velocity. • Under present climate conditions, the lack of ability of animals to dissipate the environmental heat determines that animals suffer heat stress during, at least, part of the year. • Heat stress has a variety of detrimental impact on livestock with significant effects on milk production and reproduction in dairy cows.
Meeting the challenge of impact of climate change Strategies for adaptation and mitigation for livestock to combat with climate change can play an important role in both mitigation and adaptation. Mitigation measures could include technical and management options in order to reduce GHG emissions from livestock, accompanied by the integration of livestock into broader environmental services. In general, livestock is more resistant to climate change than crops because of its mobility and access to feed. However, it is important to remember that the capacity of local communities to adapt to climate change and mitigate its impacts will also depend on their socio-economic and environmental conditions, and on the resources they have available. The basic management schemes for reducing the impact of climate change could be as follows: (a) Physical modification of the environment: Changes in livestock practices could include: • Diversification, intensification and/or integration of pasture management, livestock and crop production • Changing land use and irrigation • Altering the timing of operations • Conservation of nature and ecosystems • Modifying stock routings and distances • Introducing mixed livestock farming systems, such as stall-fed systems and pasture grazing. (b) Genetic development of less sensitive breeds: Many local breeds are already adapted to harsh living conditions. However, developing countries are usually characterized by a lack of technology in livestock breeding and agricultural programmes that might otherwise help to speed adaptation. Adaptation strategies address not only the tolerance of livestock to heat, but also their ability to survive, grow and reproduce in conditions of poor nutrition, parasites and diseases (Hoffmann, 2008). Such measures could include: • Identifying and strengthening local breeds that have adapted to local climatic stress and feed sources; 54
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Improving local genetics through cross-breeding with heat and disease tolerant breeds. If climate change is faster than natural selection, the risk to the survival and adaptation of the new breed is greater. (c) Livestock management systems: Efficient and affordable adaptation practices need to be developed for the rural poor who are unable to afford expensive adaptation technologies. These could include • Provision of shade and water to reduce heat stress from increased temperature. Given current high energy prices, providing natural (low cost) shade instead of high cost air conditioning is more suitable for rural poor producers; • Reduction of livestock numbers – a lower number of more productive animals lead to more efficient production and lower GHG emissions from livestock production (Batima, 2007); • Changes in livestock/herd composition (selection of large animals rather than small); • Improved management of water resources through the introduction of simple techniques for localized irrigation (e.g. drip and sprinkler irrigation), accompanied by infrastructure to harvest and store rainwater, such as tanks connected to the roofs of houses and small surface and underground dams. (d) Market responses: The agriculture market could be enhanced by, for example, the promotion of interregional trade and credit schemes, introducing subsidies, insurance systems, income diversification practices and establishing livestock early warning systems and other forecasting and crisis-preparedness systems –could benefit adaptation efforts. (e) Capacity building for livestock keepers: There is a need to improve the capacity of livestock producers and herders to understand and deal with climate change increasing their awareness of global changes. In addition, training in agro-ecological technologies and practices for the production and conservation of fodder improves the supply of animal feed and reduces malnutrition and mortality in herds.
Mitigation of greenhouse gas emission in livestock sector Several mitigation options are available for methane emissions from livestock. In India, the possibility of capturing or preventing emissions from animal manure storage is limited as it is extensively utilized as fuel in the form of dry dung cakes. Hence, the scope of decreasing methane from livestock largely lies in improving rumen fermentation efficiency. There are a number of nutritional technologies for improvement in rumen efficiency. • Diet manipulation, direct inhibitors, feed additives, propionate enhancers, methane oxidizers, probiotics, defaunation and hormones (Moss, 1994). Field experiments in India involving some of these options have shown encouraging results with reduction potential ranging from about 6 to 32%. • Dietary manipulation through increased the green fodder decreased methane production by 5.7% (Singhal and Madhu Mohini, 2002). Increasing the concentrate in the diet of animals reduced methane by 15–32%, depending on the ratio of concentrate on a diet (Singh and Madhu Mohini, 1999). The methane mitigation from molasses urea supplementation was 8.7% (Srivastava and Garg, 2002) and 21% from use of feed additive monensin (De and Singh, 2001).
Conclusion The livestock development strategy in the changing climate scenario should essentially focus on minimization of potential production losses resulting from climate change, on one hand, and on the other, intensify efforts for methane abatement from this sector as this would also be instrumental in 55
increasing productivity of livestock by reducing energy loss from the animals through methane emissions.
References and further reading Baker B, Viglizzo JF, 1998. Rangelands and livestock. Chapter 9. In: Feenstra JF, Burton I, Smith, JB, Tol RSJ (Eds.). Handbook of methods for climate change impact assessment and adaptation strategies. IVM/UNEP Version 2.0. Batima P, 2007. Climate change vulnerability and adaptation in the livestock sector of Mongolia. Assessments of impacts and adaptations to climate change. International START Secretariat, Washington DC, US. De D, Singh GP, 2001. Monensin enriches UMMP upplementation on in vitro methane production in crossbred calves. In: Proceedings of the X Animal Nutritional Conference (Abstract papers), Karnal, India, 2001, Animal Nutrition Society of India, National Dairy Research Institute, 161. Hoffmann I, 2008. livestock genetic diversity and climate change adaptation. Livestock and Global Change conference proceeding. May 2008, Tunisia. Intergovernmental Panel on Climate Change (IPCC), 1996. Climate change 1995: Impacts, adaptations, and mitigation of climate change: Scientific-technical analyses. The Cambridge University Press, Cambridge. Moss AR, 1994. Methane production by ruminants – literature review of I. Dietary manipulation to reduce methane production and II. Laboratory procedures for estimating methane potential of diets. Nutrition Abstracts and Reviews Series B 64: 786–806. Singh GP, Madhu Mohini (1999) Effect of different levels of monensin in diet on rumen fermentation, nutrient digestibility and methane production in cattle. Asian Australian Journal of Animal Science 12: 1215–1221. Singhal KK, Madhu Mohini, 2002. Uncertainty reduction in methane and nitrous oxide gases emission from livestock in India. Project report, Dairy Cattle Nutrition Division, National Dairy Research Institute, Karnal, India, pp. 62. Srivastava AK, Garg MR, 2002. Use of sulfur hexafluroide tracer technique for measurement of methane emission from ruminants. Indian Journal of Diary Science 55: 36–39. Thornton P, Herrero M, Freeman A, Mwai O, Rege E, Jones P, McDermott J, 2008. Vulnerability, Climate Change and Livestock – Research Opportunities and Challenges for Poverty Alleviation. ILRI, Kenya.
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Impact of climate change in horticulture A. Thirugnanavel Introduction India is unique in its soil and climate with several agro-ecological regions. It gives an opportunity to grow a wide range of fruits, vegetables, flowers, spices, medicinal plants and plantation crops. India is the second largest producer of fruits and vegetables in the world. Horticultural crops nearly occupy 8% of the cropped area and contribute approximately 30% in agricultural GDP. In India, horticultural crops are cultivated in an area of approximately 21.825 million ha with the production of 240.531 million tonnes during 2010 – 2011 (NHB, 2011). Horticultural crops play a vital role in livelihood of rural farmers. Cultivation of these crops creates more employment opportunities than agricultural crops and they are rich in carbohydrates, vitamins, minerals and vital antioxidants. Mango, banana, guava, citrus species, grapes, apple, pineapple, ber, aonla, pomegranate, tomato, chillies, brinjal, cucurbits, crucifers, rose, gerbera, carnation, ginger, turmeric, cardamom, coconut, arecanut, tea, coffee, etc. are the major horticultural crops cultivated in India which acts a crucial role In the recent past, sharp decline in production and productivity of few crops at few localities is reported, apple, tea and small cardamom in particular. Outbreak of pest and disease, low quality planting materials, poor orchard management may be the few causes that affect the production. Besides, the climate is one of the main factors which controls the production and productivity of the crops. Increasing CO2 concentration in the atmosphere results in high temperature and it was reported that the air temperature was increased 1.4°C to 5.8°C globally and it significantly altered the rainfall distribution pattern (Houghton et al., 2001). Changing climate had significant impact in India, especially in agriculture, water, natural ecosystems, health and biodiversity. Industrial air pollution, automobile emissions, etc. aggravates the climate change further. Climate change and reduction in rainfall drastically affects the productivity of the crops. Addressing the climate change in the future to improve the crop productivity will be the major task in the Indian horticultural industry. Few major changes observed in horticultural crops due to climate change are mentioned below. • Cultivation pattern is altered due to rise in temperature. • Rise in temperature in winter would affect the temperate fruit crops. • Pollination is severely affected due to pollen abortion, reduced bee activity, etc. • Water requirement of crops is increased • Crop maturity is hastened by high temperature that affects the quality. • Higher temperature affects the tuber formation in potato, anthocyanin content in apple and flower abortion in tomato etc.
Climate change impact on production The impacts of climate change on production and productivity of several horticultural crops are very much pronounced. Increase in temperature coupled with less rainfall affected the yield drastically in tropical and subtropical zones of India. In temperate zones, the reduction in duration and amount of snowfall has negative impact on chilling requirement of temperate fruit crops like apple, flower crops like Rhododendron, Orchid, Tulipa, Alstromerea, etc. and high priced spice like saffron. During the last few years, the occurrence of flash floods, drought, heat waves and cold waves become a common phenomenon in India which could cause severe yield loss. A study conducted in Kerala and Karnataka revealed that increase in temperature during November to May and reduction or absence of summer showers during March drastically reduced the small cardamom yield. 57
Apple production is affected due to climate change for the last three decades. The atmospheric temperature raised upto 1.5oC since 1980’s. Due to increase in temperature and reduction in snowfall, the traditional apple growing in Himachal Pradesh like Kullu valley in Kullu district, Rajgarh in Sirmaur district, Theog and Kotkhai in Shimla district, Churag and adjoining areas in Mandi district and some areas in Solan district faces poor fruit set that severely affects the fruit yield and quality. At the same time, the apple cultivation is shifted to Kinnaur, Lahaul and Spiti, the high altitude regions (Gautam et al., 2014). Recent past, North Indian plains were experiencing very low temperatures during winters which influence the vegetable crop production. For example, cold wave during December 2002 to January 2003 caused considerable damage to brinjal, tomato and potato crops. In cucumber sex expression is affected by low temperatures leading to more female flowers and high temperatures lead to more male flowers. Kumar et al. (2009) stated that the rise in temperature during winter drastically reduced the bolting in cabbage which resulted in poor seed yield.
Climate change impact on pest and disease incidence The pest and diseases are important which are directly affecting the production and productivity. Further climate change aggravates the situation. The crops are under threat by new fungal and bacterial pathogens. The pathogens are continuously mutating and become more virulent and cause severe yield loss. Vegetable crops are more vulnerable than fruit crops. For example, tomato is much affected by the infestation of bacterial wilt, fungal wilt, leaf curl virus and spotted wilt virus both in open field and polyhouse. The life cycles of vectors have been reduced due to high temperatures that facilitated its faster multiplication. These vectors become virulent and continuously spread the virus and fungal pathogens. Further, the prevailing climatic conditions favour the faster development of the pathogens. Climate change would affect the population dynamics of insect pests which may be directly on its distribution or population and indirectly affects the host plant, competitors and natural enemies (Porter et al., 1991). Warm temperature reduced the time required to reproduce. For example, increase in 2oC would increase the life cycle by one to five times per season in aphids (Yamamura and Kiritani, 1998). In contrary, the prolonged drought significantly affects the soil borne pests. Study conducted by Johnson et al. (2010) revealed that the hatchability of Scopelosaurus lepidus severely affected and the eggs did not hatch under prolonged drought.
Climate change impact on quality The growth of fruits and vegetables will be directly related to the climatic conditions. Any change in growing environment severely affects the growth rate and could have a profound effect on its post harvest quality. Temperature and solar intensity affect the photosynthesis and other related changes directly. It affects the maturity, pigment synthesis and biochemical changes in fruit and vegetables. Warm temperature hasten the maturity, whereas, cool temperature delays it. The fruits which are continuously exposed to strong sunlight hasten its ripening. Eg. Grape berries exposed to direct sunlight ripen faster than the berries under shade (Kliewer and Lider, 1968). Several studies stated that the fruits exposed to direct sunlight ripe faster and have high sugar content, e.g. apple and grapes. Lurie and Klein (1991) reported that the tomatoes grown at temperatures above 36 oC for 3 days in direct sunlight resulted in good colour development, ethylene evolution, and respiratory climacteric. However, ripening was slower than freshly harvested fruit.
Strategies to mitigate the climate change (a) Breeding strategies • Screening of large scale germplasm to identify the resistant lines for biotic and abiotic stresses could help in the development of resistant varieties 58
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Evaluation of multiple stress tolerance varieties. Development of transgenic varieties will help to relieve the problem in future. Identification of potential rootstocks for heat tolerant, drought tolerant, etc. for important fruits and vegetables will help to mitigate the problems. • Use of wild relatives for the development of intergeneric hybrids in fruits and vegetables for stress tolerance. (b) Management strategies: • Use of tolerant varieties (Drought tolerant: Ruby in pomegranate, Arka Sahan in annona and Excel in fig; Salinity tolerant: Rangpur lime, Cleopatra mandarin and Bappakai in mango) • Use of resistant rootstocks (Dogridge in grapes for salinity tolerance) • Mulching will help to conserve the soil moisture (Black polythene mulch, paddy straw mulch, etc.) • Integrated management of nutrients, weeds and pest and diseases increase the yield • Use of advanced irrigation systems like drip and sprinkler irrigation saves water up to 50 % and will increase the water use efficiency • Utilization of appropriate tillage practices • Identification of cropping sequence and crop rotation
Conclusion Horticulture plays a crucial role in the upliftment of rural poor and the country’s economy. This sector is contributing in export trade and occupies a premium position in agricultural GDP. However, climate change has a profound effect on horticultural crops and change in climate directly affects the production and productivity, crop distribution, pest and disease occurrence, change in harvest and the quality of the produce. Keeping the deleterious effects in view, proper strategies will be needed to challenge the climate change in near future. The development of genetically superior varieties tolerant to biotic and abiotic stress, identification of resistant rootstocks for fruits and vegetables, multi stress tolerant varieties and good pest and disease management strategies could help to achieve the production potential with good quality produce. Further adaptation of modern technologies, multiresistant cultivars, conservation agriculture, and pressurized irrigation systems could help in attaining the good yield and quality in horticulture.
References and further reading Guatam HR, Sharma IM, Kumar R, 2014. Climate change is affecting apple production in Himachal Pradesh. Current Science 100: 498 - 499. Houghton J, Ding Y, Griggs D, Noguer M, Van der Linden P, 2001. Climate Change 2001: The Scientific Basis. Published for the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK and New York. p.881. Johnson SN, Gregory PJ, McNicol JW, Oodally Y, Zhang X, Murray PJ, 2010. Effects of soil conditions and drought on egg hatching and larval survival of the clover root weevil (Sitona lepidus). Applied Soil Ecology 44: 75-79. Kliewer MW, Lider LA, 1968. Influence of cluster exposure to the sun on the composition of Thompson seedless fruit. American Journal of Enology and Viticulture 19:175184. Kumar PR, Yadav SK, Sharma SR, Lal SK, Jha DN, 2009. Impact of climate change on seed production of cabbage in North Western Himalayas. Western Journal of Agricultural Sciences 5: 18-26. Lurie S, Klein JD, 1991. Acquisition of low-temperature tolerance in tomatoes exposed to hightemperature stress. Journal of the American Society for Horticultural Science 116:10071012. 59
National Horticulture Board Database. 2011. www.nhb.gov.in/database2011.pdf. Porter JH, Parry ML, Carter TR, 1991. The potential effects of climatic change on agricultural insect pests. Agricultural and Forest Meteorology 57: 221-240. Yamamura K, Kiritani K, 1998. A simple method to estimate the potential increase in the number of generations under global warming in temperate zones. Applied Entomology and Zoology 33: 289-298.
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Climate resilient aquaculture S.K. Das Introduction The 'Aquaculture sector' is often recognized as the sunshine sector in Indian agriculture. The sector provides nutritional security to the food basket, stimulates growth of a number of subsidiary industries, contributes to the agricultural exports and engages about 14 million people in different activities. While the inland fisheries production has registered a robust growth during this period, the growth in marine fisheries has been slower. Fish production in the country is set to cross the 13million tonne mark by 2016 from the current level of over 9 million tonnes, according to a study on fisheries brought out by the Associated Chambers of Commerce and Industry of India (Assocham). The fishery resources of the North eastern region fall within all three types of climate, i.e. tropical, sub-tropical and temperate and represent a strong biodiversity. Two principal rivers viz. Brahmaputra and Barak and their numerous tributaries harbour varieties of fish species. The region harbours several important fish species having both food and ornamental values. In fact the North East India is considered as one of the hot spots of freshwater fish biodiversity in the world. The region is endowed with a large number of flood plain wetlands (beel) and swamps (1.12 lakh ha). In addition to cold water streams, there are flood-locked plain wetland, reservoirs, lakes, ponds, paddy fields and mini barrages to support large scale aquaculture activities. Aquaculture is possibly one of the least “energy costly” of the food production sector. Carp aquaculture uses minimal industrial energy, but has a potential significance in the carbon cycle, fixing CO2 through phytoplankton. It is primarily fertilization and phytoplankton based aquaculture systems and often considered as more climate/carbon friendly than more intensive forms which utilizes considerable quantum of external energy inputs.
Impact of climate change on aquaculture There are direct and indirect impact on fisheries and aquaculture. Fish in generally suffers from two extreme climatic situations: high or low temperature and more or less water.
(a) Effect of temperature In general, fishes cannot maintain a constant body temperature like the one mammal does. Their body maintain exactly the same temperature as the water they are living in. Fishes can live in very cold or very hot water, but each species has a range of preferred temperatures. Most fish cannot survive in temperatures too far out of this range. When fish encounter water that is too cold for them, their metabolic activities slow down and become lethargic. On the contrary, as the surrounding water warms up, metabolic activities speed up and they digest food more rapidly, grow more quickly, and eventually have more energy for reproduction. However, fish need more food and more oxygen to support this higher metabolism. During winter months when the water temperature in the pond/ mini-barrage falls below the optimal range, the rate of application of artificial feed and fertilizers /manures should be reduced. Generally, the rate of all the biochemical reactions in aquatic organisms doubles with every 10°C rise in water temperature. Higher water temperature adversely influences solubility of oxygen in water. As a result, fish growth depends on the water temperature to a large extent. For the Indian major carps (IMCs) fish species (Rohu, Catla and Mrigal) 25 to 32°C has been found to be optimal for their growth and reproduction in the plains. Since water temperature in the hills is usually less than 20°C even during the warmer months, the exotic carps (common, grass and silver carps), mahseers and other such coldwater fishes that can grow and survive at lesser temperatures than IMCs are more suitable for use in hill aquaculture. Similarly, when the water temperature increases 61
to 20°C in cold water fish ponds, shaded areas (e.g., water hyacinth’s canopy) may be provided in one corner of the pond for providing shelter to the fishes during the warmer hours of the day. All cultured aquatic organisms are poikilotherms . Hence, any temperature change impacts on production. There is the possibility of being higher than the optimal temperature range. The temperate species are mostly affected due to rise in temperature. In the tropics, impacts are positive; higher growth and production; but will need more feed inputs. Due to global warming, there will be eutrophication and increased stratification in inland waters. Fish may die during dawn hours. Further, the ice melting and sea level rise will result in saline water intrusion and increased acidification. There may be an overall decline in ocean productivity, change in monsoon patterns and extreme weather events. The freshwater fish could be moved further upstream due to sea level rise. There would be more demand for euryhaline species, including shrimp for increased aquaculture production. Some areas may become unsuitable for terrestrial agriculture, thus aquaculture may provide alternative livelihoods. The whole of Asia is known for the highest aquaculture activity. The number of small scale farmers is more in Asia, which is often family owned and family run. Therefore, impacts on many households; livelihoods are expected due to changes in weather patterns and extreme events. Not many adaptive measures are available, however cluster insurance is promoted. This will enable a resurrection of the occupations. The impacts on production may be temporary.
(b) Effect of water stress The predicted stress is decreased in water availability in major rivers in Central, South, east and South-East Asia – areas where there are major aquaculture activities at present. The deltaic areas of some of the major rivers where intense aquaculture activity is seen e.g., Mekong, MeghnaBrahamaputra and Ayeyarwaddy may be affected. Due to water stress, water availability in major river systems has to be considered in conjunction with saline water intrusion arising from sea level rise including the expected changes in precipitation/ monsoon patterns. Climate change will also affect wetlands and their species, e.g. through biological responses to changes in temperature, rainfall, water regimes, salinity etc. Wetlands play important roles in the global cycling of water, and the storage and cycling of carbon gases – these cycles will be affected by climate change. In semi intensive aquaculture, the fish farms can be prepared for approaching high water temperatures by: (i) providing oxygen supplementation, and (ii) changing feeding regimes, recirculating water/ aeration, and de-stocking. Reduced water level increases the catch per unit effort in the inland capture fisheries. Concentrate fish in deeper pools, fish are squeezed into less water; which can make them more vulnerable to exploitation (Fishing, etc.). Future fishing opportunities could be harmed by overharvest. Water quality changes: Very high temperature, coupled with critically low water levels can reduce the buffering capacity of water, deplete oxygen and increase toxicity due to algal blooms. These stresses can affect the fish growth and biomass production and even lead to mass mortality. It is necessary to kept at least two feet of water loss from evaporation and seepage during the drought, and plan on a minimum depth of three feet of water during the drought with minimum of five feet total depth.
Mitigation and adaptation options (a) Pond management during drought: Grow-out ponds with 1.5- 2.0 m water depth and having good water holding capacity are ideal for withstanding the temperature shock during the summer. In case of ponds with the lowest water depth, biomass needs to be reduced proportionately through partial harvesting. A cautious approach should be adopted while using manure and fertilizer (to avoid algal blooms and eutrophication). Rising water temperature may reduce the pulling of food supplies that fish in upper layers depend on and the increased carbon dioxide in the atmosphere will increase the acidity of water bodies adversely affecting the fish. 62
(b) Short-term culture of alternate species due to water stress: • Adoption of short-term (August/September to February/March) culture of species having rapid initial growth. • Medium carps like silver barb (Puntius gonionotus), Olive barb (Puntius sarana), Bata (Labeo bata), Gonius (Labeo gonius) and Labeo fimbriatus are ideal candidates for summer season due to their rapid initial growth and market preference, even at smaller size (200250 g). • The culture of the minor carp, mola carpet (Amblypharyngodon mola) is another summer option for utilizing the small shallow ponds. Being an auto-breeder fish that breeds two to three times in a year, this fish helps in auto-stocking of the pond during summer. (c) Pen culture of fish and prawn in derelict water bodies/ lakes/ floodplain wetlands during flood: Shallow areas can be made use of for raising table size fishes and prawns in enclosure (pens). However, assessment of water depth, (at least 1 m water depth for 3-4 months), duration of water availability and seed availability (IMC: 10-15cm length @ 10,000-15,000 nos. ha1 ) are required. Erecting pens of suitable size and shape, depending on the capacity of water bodies and topography of the area may result in higher production. Pens of 1000 to 2000 sqm size are economical and ideal for comfortable operation. Cage culture can also be installed in any suitable body of water, including lakes, ponds, mining pits, streams, or rivers with proper water quality. (d) Rice-Fish farming: Fish culture can adapt to climate change through the integration of aquaculture and agriculture- which can help farmers cope with drought while boosting profits and household nutrition. Fishes can be cultivated in paddy fields either simultaneously or in rotation. Paddy fields of any size can be utilized for this, subject to availability of adequate water in time and space. Fish production @ 500-800 kg ha-1 can be achieved if proper managerial practices are followed. Research is needed to build capacity to adapt and respond to climate change and the creation of AWARENESS among the stakeholders should be given due importance.
References and further reading Das SK, 2010. Lead paper presented on Fisheries & Aquaculture in the Workshop on preparation of district wise contingency plan. Organized by CRIDA, ICAR; Hyderabad and ICAR RC NEHR, Umiam, Meghalaya on 8th June, 2010. Das SK, 2012. “Strategies for climate resilient freshwater fisheries production- Progress made” at National workshop on Strategies for climate resilient agriculture in NEH Region organized by ICAR RC NEHR at Umiam, Meghalaya on 28-29th February,2012. .
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Managing vulnerable agro-ecosystem through horticulture based farming Bidyut C Deka, Dibyendu Chatterjee and A. Thirugnanavel Introduction In some agro-ecosystem, sustainability in livelihood is threatened by a complex and interrelated range of natural, human induced and environmental changes, called as vulnerable agroecosystem. Assessing these threats and sharing lessons learned to reduce vulnerability is difficult because of multiple definitions of vulnerability, complexities in quantification, and the temporal and spatial variability inherent (Reynolds et al., 2007). Even vulnerability occurs when relatively small climatic changes have commensurately large and negative impacts on agro-ecosystem (Fraser, 2006). Vulnerability is a function of: (a) agro-ecosystem resilience that measures the extent to which the agro-ecosystem can tolerate climate shocks and remain productive; (b) socio-economic affluence that measures the extent to which households will have access to the assets needed to maintain livelihoods in the event of environmental shock; and (c) institutional capacity that measures the extent to which institutions in society will provide effective crisis relief (Fraser, 2007). The approach requires strong synergies with the dynamic sustainability as advocated by Leach et al. (2010).
Type of vulnerability (a) Vulnerability in hill agro-ecosystem: (i) Traditional shifting cultivation: Traditional system (Fig. 1) is simply a mixed cropping in a slashed and burnt land with traditional cultivars of upland rice, maize and colocasia, etc. (Chatterjee et al., 2012). Seeds are either broadcasted or dibbled depending upon the slope. Generally, neither Fig. 1: Traditional methods of jhum at Nagaland application of any form of nutrients nor any improved weed management technologies are practiced in jhuming. Farmers harvest the produce by cutting the panicles, cob and digging out the tubers. (ii) Rockiness in hills: The farmers refuse to grow crops in many of the hills due to rockiness and steep hills. The reasons for such were not only extremely rocky soils, but also poor nutrient density per unit volume of soils. In Nagaland, farmers even feel reluctant to grow fruit trees in stony and rocky hills because of poor return even after taking the best management practices. (iii) Soil and nutrient loss: In Asia, deforestation accounted for 40% of the soil erosion (Barbier, 1998). Research finding showed that excessive deforestation coupled with shifting cultivation practices have resulted in tremendous soil loss (200 t ha-1 yr-1; Prasad, 1987). In another experiment it was observed that shifting cultivation had the soil loss to the extent of 30.2–170.2 t ha-1 yr-1 indicating the need to adopt tree-based land-use systems for resource conservation (Saha et al., 2011). The loss of top soil results in the huge amount of nutrient loss and uncountable loss of soil biodiversity, which in turn lead to the environmental degradation in this region. The most significant on-site effect of soil erosion is loss of soil fertility (Barbier, 1998). Jhum results in depletion of organic matter and subsequent decrease in availability of phosphorous, nitrogen and microbial biomass C, N, and P (Arunachalam, 2002). Microbial biomass C increased gradually as
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cultivation progressed, while microbial biomass N and P showed a post-burn decreasing trend (Arunachalam, 2002). Annual area under shifting cultivation in some selected northeastern states of India (Sharma and Sharma, 2004) is listed in table 1. Among the all north eastern states, Nagaland has the lowest annual area, but the number of families involved in shifting cultivation is more. Therefore, socioeconomically this system is very important. Table 1: Annual area under jhum cultivation in some selected northeastern states of India State Annual Area % of Annual soil of Total area No. (ha × 103) cultivated area affected families loss (ha × 103) (103) (×106 tonnes) Arunachal 70 59.3 210 54 14.5 Meghalaya 53 27.4 265 53 14.1 Mizoram 63 96.9 189 50 13.0 Manipur 90 64.2 360 70 20.4 Nagaland 19 10.3 191 116 8.1 (iv) Loss of forest biodiversity: Every day around two species are in the verge of extinction (Bawa and Ashton, 1997). Therefore, conservation of all flora and fauna species is to be ascertained for the humans’ survival in this planet. Moreover, those wild relatives of the cultivated species possessed a diversified variety of genes. Deforestation and fragmentation pose more serious challenges to biodiversity and wild genetic resources than climatic change (Bawa and Dayanandan, 1998). Arunachalam (2002) reported that, microbial biomass C, N, and P was high in the forest stand than jhum land. Microbial biomass C increased gradually as cultivation progressed, while microbial biomass N and P showed a post-burn decreasing trend. Bacterial and fungal populations were drastically reduced following slash burning. For Instance, 1-year-old jhum fallow counts 1.70 × 104 no. of bacterial colonies and 0.74 × 103 no. of fungal colonies g-1 dry soil which are significantly lesser than the undisturbed natural forest, Sacred Grove, having 3.45 × 104 no. of bacterial colonies and 2.70 × 103 no. of fungal colonies g-1 dry soil (Arunachalam et al., 1999). A study (Singh et al., 2003) indicates a significant decrease in propagule populations, species abundance, and diversity of VAM fungi in the jhum fallow site even after five years of regeneration period as fallow land after slash-and-burn agriculture in comparison to natural forest site. (v) Weed menace: Most of the hill farmers grow crops in the hill without applying any synthetic pesticide. Because of intermittent occurrences of rain during the early growth stage of cropping, weeds like Digitaria sanguinalis, Eluesine indica, Borreria hispida, Ageratum conyzoides, Amaranthus viridis, Chromolaena odorata, Commelina benghalensis, Mimosa pudica etc. emerge early and grow rapidly (Debbarma and Singh, 2007). This results in heavy weed infestation within a short span. Besides, cultivation of crops in the virgin forest-land after the cleaning of native trees and shrubs leads to more menace of weeds than in conventional cultivation system in plane agroecosystem. As a consequence, the productivity is far lesser than the productivity in planes. Research in the region reveals the weed infestation is more severe in upland condition (71%) compared with wetland (29%) condition (Hazarika et al., 2001). Weed causes heavy damage to direct seeded rice crop, which may be 5-100% (Kolhe, 1989). (vi) Low productivity: Agricultural production in the hills is limited by several factors viz., low temperature, small terraces, fragmented and highly scattered fields with gravelly and shallow soils, negligible use of inorganic fertilizers, inadequate farm implements and the cultivation of traditional crops with low yield potential (Chandra, 2006). Also, lack of proper input supply system, inefficient extension system, and improper land use pattern, non-adoption of soil and water conservation measures and migration of male population are the major constraints in enhancing crop productivity in hills (Chandra, 2006). 65
(b) Vulnerability due to adverse climate change: Climate change due to greenhouse gas emissions is expected to increase temperature and alter precipitation patterns. Many projections of climate change and its effect of agriculture are documented in Table 2 (Walling, 2014). Table 2: Projected effects of climate change on agriculture over the next 50 years Sl Climatic Expected changes by Confidence Effects on agriculture No. element 2055's in prediction 1 Temperature Rise by 1-20C. High Faster, shorter, earlier growing Winters warming seasons, range moving north more than summers. and to higher altitudes, heat Increased frequency stress risk, increased evapoof heat waves transpiration 2 Precipitation Seasonal changes by Low Impacts on drought risk, water ±10 percent logging, irrigation supply, transpiration 3 Carbon dioxide Increase from 360 Very high Good for crops, increased ppm to 450-600ppm photosynthesis, reduced water use efficiency 4 Sea level rise Rise by 10-15cm Very high Loss of land, coastal erosion increased in south and flooding, salinization of groundwater offset in north by natural subsistence/rebound 5 Variability Increases across most Very low Changing risk of damaging climatic variables. events (heat waves, droughts, Predictions uncertain floods etc) which effect crops and timing of farming operations (c) Vulnerability due to stress in natural resource: (i) Moisture stress: The water shortage is the major problem in arid and semiarid regions. In these regions the moisture stress represents the most important factor affecting plants. The vegetative growth of plants is greatly affected by the moisture stress. It is greatly reduced by decrease in available moisture before the permanent wilting percentage is reached. The effect of moisture stress on yield depends on (a) magnitude, (b) time and (c) duration of moisture stress (Abd El Rahman, 1973). The deficiency in soil moisture favours the decrease in accumulation of some ions (P and Fe) and the increase in accumulation of other ions (K, Ca, Mg, Na and Cl). The sum of total ions accumulated in the plant tissues increases appreciably with increase in soil moisture tension. This is accompanied by accumulation of more salts in the plant cell sap and the subsequent rise in osmotic pressure (Abd El Rahman, 1973). (ii) Nutrient stress: Long term studies revealed that crop productivity is reduced even after applying recommended doses of NPK fertilizers (Kumar et al., 2007). There has been a wide gap between nutrient removal and addition of plant nutrients which in turn affects the soil fertility and soil health (Naidu et al., 2007). The blanket recommendations that are currently in use are more than two to three decades old. Lot of changes has taken place in the level of input use, yield levels and intensity of cropping systems and soil fertility conditions. Recently, secondary and micronutrient deficiency level became a serious concern due to improper fertilizer management (Srinivasarao and Vital, 2007). This seems to be largely due to the unbalanced use of fertilizers. It is posing a serious threat to our food security. (iii) Salinity, sodicity and acidity: Extreme in salt concentrations and soil reaction (pH) may impose threat to agro-ecosystem. Excess salts in the root zone hinder plant roots from withdrawing water from surrounding soil. This lowers the amount of water available to the plant, regardless of 66
the amount of water actually in the root zone. The main problems of sodicity are reduced infiltration, reduced hydraulic conductivity, and surface crusting which adversely affects plant growth. Soil acidity is the major threat to North Eastern Hills of India. This acidity is due to high rainfall followed by leaching of basic cations. It causes root injury, P and Mo deficiencies restrict the growth of Rhizobium and other beneficial microbes, H+ and Al3+ toxicity, lowering of essential basic cations etc.
Mitigation options The systems approach is a holistic way of addressing a complex and interactive set of problems, including both socio-economic and biophysical aspects. It aims to identify, quantify and integrate the driving forces and interactions that shape and constrain farming systems and the management of natural resources (Roetter et al., 2000; Lockeretz and Boehncke, 2000). (a) Mitigation of acidic, sodic and alikaline soils: Salinity, acidity, and sodicity (alkali) possess the biggest threat to crop production that drastically reduces the yield and quality. These soils require specific techniques and specific management practices to reclaim. Increasing input cost, availability, and less scientific knowledge hiders the management. In such cases, horticultural crops, particularly fruit crops play a crucial role. The suitable horticultural crops for different problem soils are mentioned below (Table 3). Table 3: Suitable horticultural crops for different problem soils S.No Problem Threshold value Suitable crops Soil 1 Acidity pH 4.7-6.0 Pineapple, mandarins, strawberry, kiwi, raspberry, gooseberry, blue berry, water melon, fig, bael, plum, ginger, turmeric, potato, sweet potato, colocasia, beans, and leafy vegetables -1 2 Salinity 1.5-2.5 dS m Date, ber, aonla, grape fruit, peach, almond, plum, spinach, tomato, celery, lettuce, turnip, and beet root Guava, nuts, avocado, date, coconut, custard apple, 3 Alkalinity ESP 2-10 olive, phalsa, sapota Singh and Dagar (2005) suggested that the cultivation of jamun, tamarind, ber, guava and pomegranate in alkaline soils with minimum management was highly successful. Singh et al. (2008) evaluated eight fruit species, namely aonla, sapota, imli, ber, date, karonda, jamun, bael, pomegranate, and guava in alkaline soil (Fig. 2) at augerhole planting method. They found that the Fig. 2. Survival and growth of fruit crops in alkaline soil survival was 100 % in ber, karonda, pomegranate and jamun. Out of eight fruit species, jamun, ber and aonla reached maximum height. In general, these crops survived and developed better in alkaline soil. Dagar et al. (2008) conducted an experiment with three fruit crops viz., karonda, aonla and bael. These crops were irrigated with low saline water. The intercrops like cluster bean/pearl millet during kharif season and barley during rabi season were cultivated. The survival rate for these crops after two years was more than 90%. Among the tree species, karonda and aonla recorded maximum heights. 67
(b) Mitigation of moisture stress: Increasing demand for human use and change in rainfall pattern is producing unprecedented pressure on irrigation water. Continuous pressure on fresh water for human and industry affects the cultivation of crops. Further, a reduction in precipitation adds the pressure on agriculture crops. The adverse effects of moisture stress on crop growth can be easily managed by the cultivation of less water requiring crops and short duration crops. The following horticultural crops that need less water for cultivation will provide big relief (Table 4). Table 4: Suitable horticultural crops with less water requirement Crop Water requirement (mm) Crop Water requirement (mm) Brinjal 400 - 600 Cabbage 380 - 500 Tomato 400 - 600 Cauliflower 380 - 500 Capsicum 400 - 450 Pea 350 - 500 Beet root 300 - 350 Knol khol 380 - 500 French bean 150 - 400 Grapes 500 - 1200 Onion 350 - 500 Pineapple 700 - 1000 Potato 500 - 550 Melon 400 - 600 Cucumber 200 - 250 Radish 150 - 200 Broccoli 380 - 500 Okra 300 - 400 Selection of suitable crop species for cultivation in the rain-fed ecosystem is very much important to get optimum yield and sustainability. Further, the use of advance irrigation methods like drip irrigation helps to save the water and improve the yield. The effect of drip irrigation and surface irrigation (farmers’ practice) on water saving and yield of different horticultural crops was studied by IIT, Kharagpur. They reported that the drip irrigation saved the water by 30 – 50% and improved the yield over conventional methods (Table 5). Table 5: Yield of horticultural crops as influenced by the method of irrigation Irrigation (cm) S. No Crop Yield (q ha-1) Surface Drip Surface Drip 1 Bitter Gourd 32.00 43.00 76.00 33.00 2 Brinjal 91.00 148.00 168.00 64.00 3 Broccoli 140.00 195.00 70.00 60.00 4 Cauliflower 171.00 274.00 27.00 18.00 5 Chilly 42.30 60.90 109.00 41.00 6 Cucumber 155.00 225.00 54.00 24.00 7 Ladys Finger 100.00 113.10 53.50 8.60 8 Onion 284.00 342.00 52.00 26.00 9 Potato 172.00 291.00 60.00 27.50 10 Raddish 10.50 11.90 46.00 11.00 11 Sweet potato 40.40 58.90 63.00 25.00 12 Tomato 61.80 88.70 49.80 10.70 13 Banana 575.00 875.00 176.00 97.00 14 Grapes 264.00 825.00 53.00 28.00 15 Papaya 130.00 230.00 228.00 73.00 16 Pomegranate 34.00 67.00 21.00 16.00 17 Water melon 82.10 504.00 72.00 25.00 (c) Mitigation of climate change: IPCC has projected that the global temperature is expected to increase by 0.5 – 1.2 0C at 2020 and by 0.88 – 3.16 0C at 2050 (IPCC, 2007). The increase in temperature during rabi season will be more than during kharif season in India. Such increase in temperature will affect agriculture through the direct or indirect effects on crops, soil, pest, diseases and fertilizer use efficiency. Several studies on impact of climate change showed that the suitable areas for specific crops became 68
marginally suitable. To address the issue, meticulous planning and strong strategies are required to improve the production and productivity. Selection of hot or cold resistant varieties/hybrids, adjusting the sowing and planting time, development of technologies for increasing water use efficiency, and management of moisture stress will be the best solution for mitigating the climate change. The following crop varieties can be suggested to different abiotic stress affected areas to mitigate the adverse effect of climate change (Table 6). Table 6: Tolerant varieties of horticultural crops to resist adverse effect of climate change Crop Variety Tolerant Pomegranate Ruby Drought tolerant Annona Arka Sahan Drought tolerant Fig Deanna and Excel Drought tolerant Tomato Arka Vikas Drought tolerant Onion Arka Kalyan Drought tolerant Chilli Arka Lohit Drought tolerant Capsicum IIHR Selection - 3 High temperature tolerant French bean IIHR -19-1 High temperature tolerant Peas IIHR-1 and IIHR-18 High temperature tolerant Dolichos bean Arka Jay, Arka Vijay, Arka Amogh Photo insensitive Cardamom RRI, Green Gold Drought tolerant Strategies for mitigating climate change: (i) development of varieties or hybrids tolerant to heat, cold and moisture stress, (ii) identification and development of suitable rootstocks for different fruit crops to tolerate the abiotic stress, (iii) development of new technologies for soil and water conservation for dry land horticulture, (iv) development of technologies for increasing water use efficiency and nutrient use efficiency of horticultural crops suitable for small and marginal farmers, (v) identification of location specific inter crops for fruit crops, (vi) adoption of frost management in horticulture, and (vii) strengthening the agro-advisory services to farmers. (d) Mitigation of vulnerability in hill agriculture (i) Selecting suitable crops as per altitude: Suitability of crops depends upon the altitude, soil and climatic conditions. The following crops can be grown in cultivated waste/ jhum lands with proper planning and care (Table 7). Table 7: Suitable horticultural crops as per altitude S.No Altitude (above msl) Suitable crops 1 High hills (900 – 2000 Apple, peach, pear, plum, apricot, kiwifruit, strawberry, m) potato, colocasia, cabbage, cauliflower, radish, beans, etc. 2 Mid hills (below 800 Citrus, banana, pineapple, papaya, guava, ginger, m) turmeric, chilli, brinjal, tomato, bean, sweet potato, tapioca, colocasia, etc. 3 Foot hills Jackfruit, arecanut, cashew nut, coconut, black pepper etc. (ii) Horti-based farming system model for improving jhum: In this system (Fig. 3, Chatterjee et al., 2012) of farming the top area is covered with forest trees and the contour bunds or trenches on the slopes are planted with horticultural crops. Border of the contour bunds can be used for growing of pineapple. For planting of different fruit crops like Khasi mandarin, litchi, Assam lemon etc.; half moon terraces can be constructed for conservation of soil and water. Grafted planting materials must get maximum priority. In the first year, agricultural crops may be intercropped with the fruits. On top of the hills, leguminous cover crops like green gram, soybean, cowpea and rice bean may be sown. These crops have the ability to fix atmospheric nitrogen and prevent soil erosion through reducing the slashing action of raindrops on the top soils. Mid slope can be utilized as nutritional garden by growing long yard bean, brinjal, chilli, and ladies 69
finger etc. with cover crops. Kharif rice followed by can be grown in bottom to avail the high moisture content of bottom soil throughout the growing period. High yielding varieties should be grown. Nutrient sources like FYM, vermicompost and recycled biomass may be used. Mulching can be done for soil moisture conservation.
Fig. 3: Horticulture based improved jhum A worthwhile example of horti-based farming system has been observed in Lampong Sheanghah of Nagaland where the jhumias adopt agroforestry + large cardamom system. It has been observed that cardamom as intercrop does not affect the growth of multipurpose tree species and the farmers get additional income from large cardamom (Deka et al., 2013).
References and further reading Arunachalam A, 2002. Dynamics of soil nutrients and microbial biomass during first year cropping in an 8-year jhum cycle. Nutrient Cycling in Agroecosystems 64: 283–291. Arunachalam K, Arunachalam A, Melkania NP, 1999. Influence of soil properties on microbial populations, activity and biomass in humid subtropical mountainous ecosystems of India. Biological Fertility of Soils 30: 217–223. Barbier EB, 1998. The Economics of Land Degradation and Rural Poverty Linkages in Africa. UNU/INRA Annual Lectures on Natural Resource Conservation and Management in Africa, November 1998, Accra, Ghana. Bawa KS, Ashton P, 1998. In: Falk DA, Holsinger KE (Eds.), Genetics and Conservation of Rare Plants. Oxford University Press, pp. 62–71. Bawa KS, Dayanandan S, 1998. Global climate change and tropical forest genetic resources. Climatic Change 39: 473–485. Chandra N, 2006. Economics of wheat production in the farmer’s fields in Uttaranchal. Indian Research Journal of Extension Education. 6: 1-4. Chatterjee D, Deka BC, Patra MK, Thirugnanavel A, Borah TR, Kuotsu R, Ngachan SV, 2012. Resilient shifting cultivation for sustainable soil-water-nutrient-plant continuum in hilly agriculture system of North Eastern India. In: Deka BC, Patra MK, Thirugnanavel A, Chatterjee D, Borah TR, Ngachan SV (Eds.) Resilient Shifting Cultivation: Challenges and Opportunities, Published by: Director, ICAR Research Complex for NEH Region, Umiam 793103, Meghalaya, pp. 104-109. 70
Dagar JC, Tomar OS, Minhas PS, Singh G, 2008. Management of dryland biosaline agriculture: Hisar Experience. Technical Bulletin. CSSRI, Karnal. Debbarma K, Singh MK, 2007. Effect of time and doses of common salt and 2,4-D application on weed growth and yield of upland direct seeded rainfed rice. Indian Journal of Weed Science 39: 241-242. Deka BC, Chatterjee D, Sahoo B, Patra MK, Thirugnanavel A, Kumar R, Krose M, Bhatt BP, Ngachan SV (Eds.) 2013. Soil-Water-Plant-Animal-Society continuum approach for livelihood improvement of Konyak tribe of Mon in Nagaland. Published in March 2013, ICAR Research Complex for NEH Region, Nagaland Centre, Jharnapani, Medziphema-797 106, Nagaland Fraser EDG, 2006. Food system vulnerability: using past famines to help understand how food systems may adapt to climate change. Ecological Complexity 3: 328-335. http://dx.doi.org/ 10.1016/j.ecocom.2007.02.006 Fraser EDG, 2007. Travelling in antique lands: using past famines to develop an adaptability/resilience framework to identify food systems vulnerable to climate change. Climate Change 83:495-514. http://dx.doi.org/doi:10.1007/s10584-007-9240-9 Hazarika UK, SinghR, Singh NP, 2001. Ecological distribution of weed flora in Meghalaya: their intensity of occurrence in field crops and management (Technical Bulletin) Division of Agronomy, ICAR Research complex for NEH region, Umiam –793103, Meghalaya, India, pp. 3. IPCC, 2007. Climate change 2007: Climate Change Impacts, Adaptation and Vulnerability. Summary for Policymakers. Intergovernmental Panel for Climate Change. Kolhe SS, 1989. Weed management in direct seeded upland rice. Ph.D. Thesis submitted to IIT, Kharagpur. p. 271. Kumar A, Tripathi HP, Yadav DS, 2007. Correcting Nutrient Imbalances for Sustainable Crop Production. Indian Journal of Fertilizers 2: 37-44 & 60. Leach M, Scoones I, Stirling A, 2010. Dynamic sustainabilities: technology, environment, social justice. Earthscan, London, UK. Lockeretz W, Boehncke E, 2000. Agricultural Systems Research. (CABI, Wallingford). Naidu LGK, Kumar R, Dhanorkar SC, , Prasad BAB, Prasad S, Budhial CR, Srinivas SL, Koyal SA, Reddy RS, Harindranath CS, Krishnan P, 2007. Fetilizer Misapplication and Economic Assessment of Soil Fertility Degradation- A Case Study in Nalathwad Watershed, Karnataka. Indian Journal of Agricultural Research 41: 117- 121. Prasad RN, 1987. Degradation of soil and water resources and crop production in NEH Region. Indian Journal of Hill Farming 1: 1–8. Rahman AEAA, 1973. Effect of Moisture Stress on Plants. Phyton (Austria) 15: 67-86 Reynolds JF, Stafford DM, Smith EF, Lambin BL, Turner II, Mortimore M, Batterbury SPJ, Downing TE, Dowlatabadi H, Fernández RJ, Herrick JE, Huber-Sannwald E, Jiang H, Leemans R, Lynam T, Maestre FT, Ayarza M, Walker B, 2007. Global desertification: building a science for dryland development. Science 316: 847-851. http://dx.doi.org/ 10.1126/science.1131634 Roetter RP, van Keulen H, Laborte AG, Hoanh CT, 2000. Systems research for optimizing future land use in South and Southeast Asia. Proceedings of the SysNet’99 International Symposium. SysNet Research Paper Series 2. (International Rice Research Institute, Los Baños).
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Saha R, Mishra VK, Khan SK, 2011. Soil erodibility characteristics under modified land-use systems as against shifting cultivation in hilly ecosystems of Meghalaya, India. Journal of Sustainable Forestry 30: 301–312. Sharma UC, Sharma V, 2004. The "Zabo" soil and water management and conservation system in northeast India: tribal beliefs in the development of water resources and their impact on society- An historical account of a success story. The Basis of Civilization - Water Science? (Proceedings of the UNESCO/IAIIS/IWIIA symposium held in Rome. December 2003). IAHS Publ. p. 286. Singh G, Dagar JC, 2005. Greening sodic lands: Bichhian Model. Technical Bulletin No. 2/2005, CSSRI, Karnal, p. 51. Singh SS, Tiwari SC, Dakhar MS, 2003. Species diversity of vesicular-arbuscular mycorrhizal (VAM) fungi in jhum fallow and natural forest soils of Arunachal Pradesh, north eastern India. Tropical Ecology 44: 207-215. Singh YP, Sharma DK, Singh G, Nayak AK, Mishra VK, Singh R, 2008. Alternate land use management for sodic soils. Technical Bulletin No. 2/2008. CSSRI, Regional station, Lucknow-226005, p.16. Srinivsaarao CH, Vittal KPR, 2007. Emerging Nutrient Deficiencies in Different Soil Types under Rainfed Production Systems of India. Indian Journal of Fertilizers 3: 37-44 & 70. van Ginkel M, Sayer J, Sinclair F, Hassan AA, Bossio D, Craufurd P, El Mourid M, Haddad N, Hoisington D, Johnson N, León Velarde C, Mares V, Mude A, Nefzaoui A, Noble A, Rao KPC, Serraj R, Tarawali S, Vodouhe R, Ortiz R, 2013. An integrated agro-ecosystemand livelihood systems approach for the poor and vulnerable in dry areas. Food Security 5:751– 767 doi: 10.1007/s12571-013-0305-5 Walling I, 2014. Impact of Climate Change on Crop Production. Seminar presented at ICAR Research Complex for NEH Region, Nagaland Centre, Jharnapani, Nagaland- 797 106 (Personal communication).
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Climate change and pest population dynamics: Strategies for their management D.M. Firake, G T Behere and N.S. Azad Thakur Introduction Rapid industrialization, heavy use of fossil fuels and many other activities which increase carbon dioxide in atmosphere, have led to climate change. Rising concentration of atmospheric CO2, increase in Earth’s surface air temperature and the changes in precipitation pattern have been, three most striking phenomena associated with global climate change. These changes will definitely impact agriculture in either positive or negative way. Climate change is possibly the most significant global change event that has attracted the attention of scientific community all over the globe. With the signs of climate change becoming more and more concrete with every coming year, concerns about its possible implications for various sectors of life on the universe are also escalating. On account of its close association with climatic variables such as temperature, CO2 and precipitation, agriculture is definitely the most climate-sensitive sector. Thus, the possible impact of climate change on agriculture has been the important research topic and intensively debated in recent times. Being a highly diverse groups, insects and pathogens are perhaps the most sensitive to the changing climate. The possible effects of changing climate on pests and diseases could result in the form of outbreaks or epidemics, migration or dispersal, change in bio-diversity, species extinction, host shift, and emergence of new pests or biotypes or races etc. Therefore, insect pest management under changing climate is foremost and important challenge in agriculture sector and consensus should be made to prioritize the research activities in the area.
Components of climate change which have potential to influence insect pest scenario and thereby affect productivity • • • • •
Rise in global temperature Increased CO2 concentration Increase in Ozone concentration Increased UV radiation Extreme weather events like - floods, droughts, high intensity rainfall, and hurricanes etc.
Effect of rising temperature and CO2 on insects Changing climate can restrict the distribution of insects directly by influencing their survival and fecundity or indirectly through effects on interacting species that act as food sources, natural enemies or competitors. Closely related insects can differ markedly in their survival of climatic stresses as well as in their ability to reproduce and expand under different thermal conditions, which greatly influences the species distribution and abundance (Hoffmann, 2010). It has been reported that some short-lived species of insects have capacity to respond to climate change within a time frame of tens of years (Sgro and Blows, 2003). In general, temperature plays important role in overall development of insect. In addition, the speed of insect dispersal through different means can be affected. Generally, higher the temperature, the more rapidly insects develop and spread. Higher temperature reduces the time taken for completion of life cycles which helps insect species to complete many generations within a short period of time. Some observed impacts of increasing temperature on insects are mentioned in Table 1.
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Table 1. Impact of elevated temperatures on insects Increasing Northward migration Migration up elevation gradient Insect development rate and oviposition Potential for insect outbreaks Invasive species introductions Insect extinctions Decreasing Effectiveness of insect bio-control by fungi Reliability of economic threshold levels Insect diversity in ecosystems Parasitism Sources: Firake et al., 2013a; Das et al., 2011; Parmesan, 2006; Bale et al., 2002; Thomas et al., 2004; Trumble and Butler, 2009 As stated earlier, temperature has been thought to be the most important abiotic factor which can significantly affect the development of insects. The combined effect of higher temperatures and CO2 concentration could have high subtle effects on overall growth and development of insects. Research conducted in past has shown that effect of elevated CO2 on insect pests could occur through changes in host biochemical composition. Some observed effects of elevated CO2 on insects are shown in Table 2. Table 2. Effect of elevated CO2 on insects Increasing Food consumption by caterpillars Reproduction of aphids Predation by lady bird beetles Carbon based plant defences Effect of foliar application of Bacillus thuringiensis Consumption and N utilization efficiency in pine saw fly and Gypsy moth Larval growth in pine saw fly Growth rate and consumption in Willow beetle Pupal weight in blue butterfly Feeding and growth rate in tobacco caterpillar Fecundity of aphids on cotton Decreasing Insect development rates Development and pupal weight in Chrysanthemum leaf miner Response to alarm pheromones by aphids Lipid concentration in small heath Parasitism Effect of transgenics to Bacillus thuringiensis Nitrogen based plant defence Control of grain aphids with sticky traps Sources: Firake et al., 2013a; Das et al., 2011; Coviella and Trumble, 2000; Chen et al., 2005; Osbrink et al., 1987; Awmack et al., 1997; Roth and Lndroth, 1995.
Effect of changing precipitation on insects Small body-sized insects may be physically dislodged from the host plant by heavy rainfall, and are often more of a problem during dry seasons when the mortality factor is missing. Climate change resulting in more frequent and/or heavy rainfall would tend to suppress populations of small insects. Increase in the frequency of flooding of fields could tend to suppress some soil dwelling 74
insect populations. However, in contrast, drier conditions would have the opposite effect. Due to global warming, more droughts are expected to be observed due to shift in rainfall pattern and increment in evaporation. Most fungi which are known to cause various diseases in insects (entomopathogens) depend on high relative humidity for successful epidemics, thereby reducing insect pest populations. Higher percentage of relative humidity resulting from rainfall or larger crop canopies may tend to favor fungal epidemics (Petzoldt and Seamann, 2012).
Observed impact of climate change on insects with special reference to North East India Till date, no proper scientific study has been done in India to correlate exact effect of climate change on insects. It is really difficult to give any specific example for these interactions between insects and changing climate. However, few reports stating possibilities of involvement of climate change either directly or indirectly on insect pest outbreaks, invasion, changes in host shift and emergence of new pests etc as follows a) Pest outbreaks: • Pine lappet moth in 2011 at Umiam (Firake et al. 2012) • Litchi bug during 2012-2013 near Indo-Bangladesh border (Azad Thakur, unpublished) • Sporadic outbreaks of rice hispa in Indo-Bangladesh border (Azad Thakur, unpublished) • Sporadic outbreaks of swarming caterpillars in different parts of NEH region (Ref: News reports) • Sporadic outbreaks of grasshopper, Aularches miliaris in Manipur and Nagaland (Ref: News reports) b) Insect invasion: • Recent Invasion of Papaya mealy bug, Paracoccus marginatus in Assam, 2010 (Ref: News reports) • Recent Invasion of looper caterpillar, Hypoxidra infixaria on tea in Assam (Antony et al., 2012) c) Shifting of host by insects: • Litchi trunk borer on Guava (Shylesha et al., 2000) • Guava trunk borer on pigeon pea (Azad Thakur, unpublished) • Banana Fruit caterpillar on Dolichous bean (Firake et al., 2013b) • Elephant beetles on guava (Firake et al., 2013c) d) Emergence of new pests: • Saw fly attack on roses (Firake et al., 2013d) • Root aphid and white grubs in upland paddy (Azad Thakur, unpublished) • Mealybug on ginger rhizomes (Firake, unpublished)
Insect pest management practices under changing climate scenario a) Insects are poikilothermic organisms and thus are highly sensitive to their surrounding temperature. Increased climatic temperatures are likely to result in the need for more insecticide applications because of the likelihood of the presence of additional pest species, more generations of pests per growing season, and the earlier arrival of migratory pests (Firake et al., 2013a). Under such situations, need based pest management practices should be followed; i.e. ETL based chemical management practices, identification of pesticides with novel mode of action and delivery, identification of emerging pests or race in new habitat etc. b) Similarly, biology and life cycles of several arthropods will keep altering under changing climate that ultimately could affect many successful pest management practices including cultural control, biological control and chemical control (Petzoldt and Seamann, 2012). Therefore, these practices need be modified according to the biology and behavior of pests e.g. changes in sowing 75
time, altered doses of bio-agents and pesticides; timing of applications and proper IPM programmes against target pests. c) More insecticide applications may be required under climate change due to additional pest species, additional generations of pests, and earlier arrival of migratory pests etc. It has been observed that pyrethroid insecticides and spinosad are not as effective in killing insects at higher temperatures. Certainly, it may happen in case of fungicides also. Under such situations, some alternative management practices such as traditional management practices or ITKs should be evaluated and standardized. d) Resistant varieties which retain the resistance for pest and diseases even under altered climatic conditions should be deployed. e) Strategies based on combined use of available management options available may prove to be more effective than reliance on the fungicides alone under climate change situation.
Strategies to be undertaken to combat effect of climate change on insect pest Following strategies should be adopted to understand effect of climate change on insect pests of crops; so that we can formulate efficient and robust management practices against them without affecting the ecosystem. a) In order to completely understand the effect of changing climate on insects, the efforts on time lag bio-diversity mapping in important agro-climatic regions should be undertaken. b) Detailed understanding of the biology and the population dynamics of major insect pests under changing climate would help in developing better and efficient pest management practices in relation to climate. c) Development of forewarning systems based on short as well as long term studies on population dynamics and migration pattern of insects would ultimately help in formulating robust management strategies. d) Holistic studies concentrating on combined effects of temperature, CO2, O3 and UV on pest and diseases should be undertaken (Luc et al. 2011) e) Farming system based studies will provide better insights f) Economic and health considerations due to increased use of pesticides g) Resistance of different varieties should be evaluated under simulated conditions h) Long term studies on host-pest and host-pathogen interaction, population genetics etc. i) Crop and pest modeling based on long term weather data j) Impact of climate change on hyperparasites and bio-control agents should also be studied
References and further reading Antony B, Sinu PA, Rehman A, 2012. Looper caterpillar invasion in North East Indian tea agroecosystem: Change of weather and habitat loss may be possible causes? Journal of Tea Science Research, 2:1-5. doi: 10.5376/jtsr.2012.02.0001. Awmack CS, Woodcock CM, Harrington R, 1997. Climate change may increase vulnerability of aphids to natural enemies. Ecological Entomology 22: 366-368. Bale JS, Masters GL, Hodkinson ID, 2002. Herbivory in global climate change research: Direct effect of rising temperature on insect herbivorous. Global Climate Change Biology 8: 1-16. Chen FGF, Parajulee MN, 2005. Impact of elevated CO2 on tritrophic interaction of Gossypium hirsutum,Aphid gossypi and Leis axyridis. Environmental Entomology 34: 37-46. Coviella C, Trumble JT, 2000. Effect of elevated atmospheric CO2 on use of foliar application of Bacillus thuringiensis. Biocontrol 45: 325-336. Das DK, Singh J, Vennila S, 2011. Emerging Crop Pest Scenario under the Impact of Climate Change. Journal of Agricultural Physics 11:13-20 Dhaliwal GS, Jindal V, Dhawan AK, 2010. Insect Pest Problems and Crop Losses: Changing Trends. Indian Journal of Ecology 3:1-7. 76
Firake DM, Behere GT, Azad Thakur NS, Burange PS, Bharambe VY, 2013a. Climate Change and Insect Pests: Potential Impacts and Future Strategies. Popular Kheti 1: 67-70. Firake DM, Behere GT, Firake PD, Rajkhoa DJ, Azad Thakur NS, Saini MS, Rahman Z, Ngachan SV, 2013d. Arge xanthogaster (Hymenoptera: Argidae): A New Threat to Rose Plants in Meghalaya, India. Florida Entomologist 96:1298-1304 Firake DM, Behere GT, Firake, PD, Azad Thakur NS, Dubal ZB, 2012. An outbreak of pine lappet moth, Kunugia latipennis in mid-altitude hills of Meghalaya state, India. Phytopara doi: 10.1007/s12600-012-0228-2 Firake DM, Deshmukh NA, Behere GT, Azad Thakur N S, Ngchan SV, 2013c. First Report on Elephant Beetles of the Genus Xylotrupes (Coleoptera: Scarabaeidae) Attacking Guava in India. The Coleopterists Bulletin 67: 1–3. Firake DM, Kumar R, Firake PD, Behere GT, Azad Thakur NS, Verma VK, Deshmukh NA, Ngachan SV, 2013b. First report of Tiracola plagiata Walker (Lepidoptera: Noutuidae) attacking dolichous bean from India. Entomological News 123: 365-370. Fuhrer J, 2003. Agroecosystem response to combinations of elevated CO2, ozone, and global climate change. Agriculture, Ecosystems & Environment 97:1–20. Hoffmann A, 2010. Physiological climatic limits in Drosophila: patterns and implications. The Journal of Experimental Biology 213: 870-880. Internet-1. Accessed at http://www.wisegeek.org/how-many-species-of-insect-are-there.htm. Internet-2. Accessed at http://www.buglife.org.uk/conservation. Luck J, Spackman M, Freeman A, Trębicki P, Griffiths W, Finlay K, Chakraborty S, 2011. Climate change and diseases of food crops. Plant Pathology 60: 113–121. Osbrink WLA, Trumple JT, Wagner RE, 1987. Host suitability of Phaseolu lunata for Trichoplusiani (Lepidoptora: Noctuidae) in controlled carbon dioxide atmosphere. Environmental Entomology 16: 639-644. Parmesan C, 2007. Influences of species, latitudes and methodologies on estimates of phonological response to global warming. Global Change Biology 13: 1860-1872. Petzoldt C, Seamann A, 2012. Climate Change Effects on Insects and Pathogens. Accessed online at http://www.climateandfarming.org/pdfs/FactSheets/III.2Insects.Pathogens.pdf Pless M, Heller W, Payer H, Elstner E, Habermeyer J, Heiser I, 2005. Growth parameters and resistance against Drechslera teres of spring barley (Hordeum vulgare L. cv. Scarlett) grown at elevated ozone and carbon dioxide concentrations. Plant Biology 7: 694–705. Rosenzweig C, Yang XB, Anderson P, Epstein P, Vicarelli M, 2005. Agriculture: climate change, crop pests and diseases. In: Epstein P, Mills E (Eds.) Climate Change Futures: Health 320: 30. Roth SK, Lindroth RL, 1995. Elevated atmospheric CO2: Effect on photochemistry, insect performance and insect parasitoid interactions. Global Change Biology 1: 173-182. Sgro CM, Blows MW, 2003. Evolution of additive and nonadditive genetic variance in development time along a cline in Drosophila serrate. Evolution 57: 1846-1851. Shylesha AN, Thakur NSA, Ramchandra, 2000. Incidence of litchi trunk borer, Aristobia testudo Voet (Coleoptera: Lamiidae) on guava in Meghalaya. Pest Management in Horticultural Ecosystems 6:156-157. Thomas CD, Cameran A, Green RE, 2004. Extinction risk from climate change. Nature 427: 145148. Trumble J, Butler C, 2009. Climate change will exacerbate California’s. Insect pest problem. California Agriculture 63: 73-78.
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Effect of climate change on plant disease scenario Rajesha G and Tasvina R Borah Introduction The earth’s climate has always changed in response to changes in the cryosphere, hydrosphere, biosphere, and other atmospheric and interacting factors and it is the biggest threat of the present century to the mankind. Over the last 100 years, the global mean temperature has increased by 0.74 °C and atmospheric CO2 concentration has increased from 280 ppm in 1750 to 400 ppm in 2013 (Watson, 2001). Throughout the 21st century, India is projected to experience warming above the global mean. A warming trend has been observed along the west coast, in central India, the interior peninsula and northeast India. Plant diseases are one of the important factors which have a direct impact on global agricultural productivity and climate change will further aggravate the situation. Combined infestation of pests and diseases in plants could result up to 82% losses in attainable yield in case of cotton and over 50% losses for other major crops and if we combine these losses with post-harvest spoilage and deterioration in quality; these losses become critical particularly for resource poor regions of the world.
What is climate change? Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions, or in the distribution of weather around the average conditions (i.e., more or fewer extreme weather events). Plant pathologists already realized in the 1990s that climate change was clearly set to pose a challenge to many pathosystems. It is now recognized that climate change will affect plant diseases together by changes in temperature, precipitation, concentration of CO2, CH4, nitrous oxide (N2O) and O3 with other components of global change, i.e. anthropogenic processes such as air, water and soil pollution, long-distance introduction of exotic species and urbanization.
Effect of increased CO2 concentration on Pathogens The concentration of CO2 in the atmosphere reached 379 ppm in 2005, which exceeds the natural range of values of the past 650,000 years. In general, increased plant density will tend to increase leaf surface wetness duration and regulate temperature, and thus make infection by foliar pathogens more likely. Elevated levels of CO2 can directly affect the growth of pathogens. For example, according to Chakraborty et al. (2002), the growth of the germ tube, appressorium and conidium of C. gloeosporioides fungi is slower at high concentrations of CO2 (700 ppm). In another study Hibberd et al. (1996) evaluated powdery mildew in barley, and found that an acclimation of photosynthesis at elevated CO2 and an infection-induced reduction in net photosynthesis caused larger reductions in plant growth at elevated CO2; also, the percentage of conidia that progressed to produce colonies was lower in plants grown in high CO2 (700 ppm) than in low CO2 (350 ppm) and lower percentage of conidia producing hyphae in 700 ppm CO2, it was due to a higher proportion of the spores being arrested at the appressorial stage. Some authors suggest that elevated CO2 concentrations and climate change may accelerate plant pathogen evolution, which can affect virulence and plant-pathogen interactions. Effect of elevated concentrations of CO2 has also been evaluated on two important diseases of rice, namely blast (Pyricularia oryzae) and sheath blight (Rhizoctonia solani) and rice plants were found more susceptible to injury. In addition to high disease incidence and severity due to changes in host, reproduction of the pathogens has also been reported to increase at high CO2 levels in 78
barley powdery mildew and anthracnose (Colletotrichum gloeosporioides). Overall, the effects of elevated CO2 concentration on plant diseases can be positive or negative, although in a majority of the cases disease severity increased.
Impact of elevated temperature on pathogens Due to changes in temperature and precipitation regimes, climate change may alter the growth stage, development rate and pathogenicity of infectious agents, and the physiology and resistance of the host plant. A change in temperature could directly affect the spread of infectious disease and survival between seasons. A change in temperature may favor the development of different inactive pathogens, which could induce an epidemic. Increase in temperatures with sufficient soil moisture may increase evapotranspiration resulting in humid microclimate in crop and may lead to incidence of diseases favored under these conditions (Mina and Sinha, 2008). In India, in the last decade the disease scenario of chickpea and pigeon pea has changed drastically; dry root rot (Rhizoctonia bataticola) of chickpea and Phytophthora blight (Phytophthora drechsleri f. sp. cajani) of pigeon pea have emerged as a potential threat to the production of these pulses. Higher risk of dry root rot has been reported in Fusarium wilt chickpearesistant varieties in those years when the temperature exceeds 33oC. In general, increase in temperature would significantly raise the severity and spread of plant diseases but quantity of precipitation could act as regulator in deciding the increase or decrease in disease severity and spread. Temperature is one of the most important factors affecting the occurrence of bacterial diseases such as Ralstonia solanacearum, Acidovorax avenae and Burkholderia glumea. Thus, bacteria could proliferate in areas where temperature-dependent diseases have not been previously observed. As the temperature increases, the duration of winter and the rate of growth and reproduction of pathogens may be modified. Similarly, the incidence of most of the virus and other vector-borne diseases will be altered. Changes may result in geographical distribution, increased overwintering, changes in population growth rates, increases in the number of generations, extension of the development season, changes in crop-pest synchrony of phenology, changes in interspecific interactions, and increased risk of invasion by migrant pests. Genetic changes in the virus through mutation and recombination, changes in the vector populations and long-distance transportation of plant material or vector insects due to trade of vegetables and ornamental plants have resulted in the emergence of tomato yellow leaf curl disease, African cassava mosaic disease, diseases caused by bipartite begomoviruses in Latin America, Ipomovirus diseases of cucurbits, tomato chlorosis caused by criniviruses, and the torrado-like diseases of tomato. Temperature can also affect disease resistance in plants, thus affecting the incidence and severity of the diseases. Temperature sensitivity to resistance has been reported for leaf rust (Puccinia recondita) in wheat, broomrape (Orobanche cumana) in sunflower, black shank (Phytophthora nicotianae) in tobacco and bacterial blight (Xanthomonas oryzae pv. oryzae) in rice.
Effect of changed moisture regime on the disease scenario Moisture can impact both host plants and pathogens in various ways. Some pathogens such as apple scab, late blight and several vegetable root pathogens are more likely to infect plants with increased moisture content because forecast models for these diseases are based on leaf wetness, relative humidity and precipitation measurements. The trend of decreasing monsoon seasonal rainfall has been observed over eastern Madhya Pradesh, NE India and some parts of Gujarat and Kerala. Other pathogens like the powdery mildew species tend to thrive under conditions with lower (but not low) moisture. Condition of drought is also expected to lead to increased frequency of tree pathogens due to indirect effects on host physiology. In Italy, the invasive exotic species Heterobasidion irregulare appears to be well adapted to dispersal in the Mediterranean climate than the native H. annosum species. Drought stress has been found to affect the incidence and severity of 79
viruses such as Maize dwarf mosaic virus and Beet yellows virus. More frequent and extreme precipitation events that are predicted by some climate change models could result in longer periods with favorable pathogen environments. Host crops with canopy size limited by lack of moisture might no longer be so limited and may produce canopies that hold moisture in the form of leaf wetness or high-canopy relative humidity for longer periods, thus increasing the risk from pathogen infection. Salinari et al. (2006) used two climate-change models to simulate future scenarios of downy mildew on grapevine (Plasmopara viticola). These empirical models predicted an increase of the disease pressure in each decade and more severe epidemics were a direct consequence of more favorable air temperature and rainfall reduction conditions during May and June.
Impact of climate change due to elevated Ozone The direct effects of elevated ozone on spring wheat infected with Puccinia recondita f. sp. tritici. Crop yield and growth were measured for plants exposed to two levels each of carbon dioxide and ozone and either inoculated with rust or left uninoculated. Results showed that ozone damage to leaves is largely dependent on both carbon dioxide concentrations as well as disease. Additionally, elevated carbon dioxide levels appeared to reduce and delay leaf damage caused by ozone. Tiedemann and Firsching (2000) were evaluated the effects of elevated O3 on three soybean diseases: downy mildew (Peronospora manshurica), Septoria (Septoria glycines) and sudden death syndrome (Fusarium virguliforme) in combination with high concentrations of O3, increased the severity of Septoria glycines. Alternatively the concentration of CO2 and O3 did not have an effect on sudden death syndrome. The high levels of CO2 and O3 induced changes in the soybean canopy density and leaf age, likely contributed to disease expression modification. Thus, the increase in both CO2 and O3 will alter disease expression for import fungal pathogens of soybean. Young plants are generally the most sensitive to ozone; but mature plants are relatively resistant. Symptoms include tissue collapse, interveinal necrosis depressed flowering and bud formation. Ozone-killed tissues are readily infected by certain fungi.
Pathogen and vector responses to climate change The range of many pathogens is limited by climatic requirements for overwintering or over summering of the pathogen or vector. For example, higher winter temperatures of 6 °C versus 10 °C increase survivorship of overwintering rust fungi (Puccinia graminis) and increase subsequent disease on Festuca and Lolium. In the case of Phytophthora infestans, the introduction of multiple mating types, allowing sexual reproduction, increases the ability of the pathogen to overwinter. Temperature requirements for infection differ among pathogen species. For example, wheat rust fungi differ in their requirements from 2 to 15°C for stripe rust, 10 to 30°C for leaf rust, and 15 to 35°C for stem rust the introduction of new vector species and changes in vector overwintering and over summering may have important effects on pathogen survival, movement, and reproduction. For example, introduction of the glassy-winged sharp shooter has led to increased patterns of infection of grape plants in winter, greatly altering infection rates. Interactions between pathogens may also shift with climate change.
Climate change effects on virulence, aggressiveness, or fecundity of pathogens Pathogen evolution rates are determined by the number of generations of pathogen reproduction per time interval, along with other characteristics such as heritability of traits related to fitness under the new climate scenario. Temperature governs the rate of reproduction for many pathogens; for example, spore germination of the rust fungus Puccinia substriata increases with increasing temperature over a range of temperatures, and the root rot pathogen Monosporascus cannonballus reproduces more quickly at higher temperatures. Longer seasons that result from higher temperatures will allow more time for pathogen evolution. Pathogen evolution may also be more 80
rapid when large pathogen populations are present, so increased overwintering and oversummering rates will also contribute. Climate variability itself may be an important form of selection. Climate change may also influence whether pathogen populations reproduce sexually or asexually; in some cases, altered temperatures may favor overwintering of sexual propagules, thus increasing the evolutionary potential of a population. But most pathogens will have the advantage over plants because of their shorter generation times and, in many cases, the ability to move readily through wind dispersal.
Conclusion Climate change is an important phenomenon that affects agricultural production. By anticipating the future, we can prepare ourselves for problems caused by climate change, especially those related to agricultural activities, which generate the greatest amount of food consumed by humans. For several centuries, pests and plant diseases have played an important role in agricultural production. Because global warming may modify areas affected by pests and diseases, studies must be performed to assess pest and disease stages under the effects of climate change, determine the magnitude of disease and identify measures to minimize the risk of infection. The impact of climate change on disease for a given plant species will depend on the nature of the effects on both host and its pathogens.
References and further reading Chakraborty S, Murray G, White N, 2002. Impact of climate change on important plant diseases in Australia. A report for the Rural Industries Research and Development Corporation. RIRDC Publication No W02/010. Coakley SM, Scherm H, Chakraborty S, 1999. Climate change and plant disease. Annual Review of Phytopathology 37: 399-426. Gautam HR, Bhardwaj ML, Rohitashw Kumar, 2013. Climate change and its impact on plant diseases. Current Science 105: 1685-1691. Hibberd JM, Whitbread R, Farrar JF, 1996. Effect of elevated concentrations of CO2 on infection of barley by Erysiphe graminis. Physiological and Molecular Plant Pathology 48: 37-53. Mina U,Sinha P, 2008. Effects of Climate Change on Plant Pathogens. Environ. News, 14(4): 6-10. Salinari F, 2006. Downy mildew (Plasmopara viticola) epidemics on grapevine under climate change. Global Change Biology 12: 1299–1307. Tiedemann AV, Firsching KH, 2000. Interactive effects of elevated ozone and carbon dioxide on growth and yield of leaf rust-infected versus non-infected wheat. Environmental Pollution 108: 357-363. Watson RT, 2001. Climate Change 2001: Synthesis Report. A Contribution of Working Groups I, II, and III to the Third Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, UK: Cambridge.
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Horticultural crop diseases as influenced by excess or deficit moisture Tasvina R Borah Introduction Agriculture is the main source of revenue for the state, Nagaland. Jhum cultivation is predominantly practiced by the locals where in not less than 35 varieties of crops are grown. Apart from Jhum paddy which is the main adapted crop, many vegetables are grown in the Jhum lands. Of the total cropped area (474339) in the state, horticultural crops occupy sufficient area and have tremendous potential to contribute to the state economy. On the other hand Nagaland has been known to be a hotspot of biodiversity and home for pathogens. The diseases incited by these pathogens cause heavy loss of yield in terms of monetary returns. Pathogens cause severe damage under congenial environmental conditions with optimum moisture and temperature.
Crop Diseases Plant diseases generally develop with temporal interaction of three vital components– susceptible host, virulent pathogen and favourable environment. Disease in plants can be defined as the series of invisible and visible responses of plant cells and tissues to a pathogenic organism or environmental factor that result in adverse changes in the form, function or integrity of the plant and may lead to partial impairment or death of plant parts or of the entire plant. Practices aimed at preventing crop diseases usually focus on one of these factors – host, pathogen and/or environment at a time. Disease management is all about prevention–it’s easier to stop a disease from occurring than it is to manage it once it starts spreading.
Moisture for crops Water or moisture influences almost all the biochemical and physiological processes in plants which in turn affects the morphology of plants as well as their potential. All the crop plants have an optimal moisture regime and any deviation from the optimum, results in adverse effect leading to poor growth, yields and even the quality of the produce. In other words excess or less of the optimum moisture for crops makes them prone to pathogen attack and diseases occur.
Disease spread and water Water, besides wind, is the second important factor for dispersal of plant pathogens. Rain showers, trickling drops from infected leaves and twigs, splashes, irrigation and flood water are some of the ways water helps in dispersal of inoculum. Most plant pathogenic fungi, almost all plant pathogenic bacteria and foliar nematode require a film or droplet of water on the plant surface in order to invade the plant. Moisture and diseases the relation: Moisture in the form of irrigation provided affects both soil-borne and foliar diseases. Irrigation has profound effects on disease incidence in relation to methods, amounts, frequency, and quality. Likewise, excess moisture with heavy rainfall and deficit moisture with no rain or drought like situation influences disease incidence, spread and management practices. Principles influencing the relation between the timing of irrigation and its frequency, with disease management include: (a) providing the crop with uniform water supply to avoid water stress or excess, (b) timing of irrigation in relation to periods of host susceptibility, and (c) minimizing period of continuous leaf wetness.
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Impact of irrigation methods and rainfall: • Furrow flooding, drip and trickle: In this method of irrigation water is placed near a plant root system without wetting the foliage. As a result there are fewer incidences of foliar diseases in horticultural crops. • Over head irrigation applied through sprinkler, centre pivot arrangements or water cannons: These methods wet the foliage of plants, due to which a favorable environment for spore germination and infection is created. In dry climate also necessary moisture for spore germination and infection is provided by these methods. Moreover, pathogen propagules are splashed from leaf to leaf and help in spread of the diseases. • Other methods – ebb and flow or flood and drain (this method is used in green houses and nurseries – where unused water is recycled back to reservoir): In this method, pathogens already in the crop or soil contaminate the reservoir and recycling the water results in inoculation of large crop area with each watering. Similarly crops in heavy and prolonged rainfall areas are affected mostly by the rotting fungi and bacteria inciting wet rots (e.g. Pythium spp., Phytophthora spp. and Erwinia spp.). Viral diseases of crops are found less in such areas but they proliferate more in warm and humid areas where the survivability and spread of the vectors is more. In comparatively warmer areas with less of rainfall, fungi like Fusarium spp., Collectotrichum spp. etc are more encountered.
Diseases of vegetable crops Damping off at nurseries: In pre-emergence damping off: seeds are destroyed and don’t germinate or young seedlings are killed before they emerge out of the soil surface. Post emergence damping off is characterised by toppling over of infected young seedlings after emergence with development of pale green and brownish lesion. Over irrigated plots or shallow beds with water ponding have the problem of damping off especially due to Pythium and Phytophthora spp. Other management strategies include: i) crop rotation. ii) soil and seed treatment with bio formulations of Trichoderma harzianum/T. viride. iii) soil and seedling treatment with 1% Bordeaux mixture. Bacterial diseases: Bacterial wilt caused by Ralstonia solanacearum, infects almost all the solanaceous vegetables like tomato, potato, brinjal and chilli and the important spice crop ginger. The symptoms mimic those of physiological wilting due to water stress and nitrogen deficiency. In ginger the disease initiates with drooping and downward rolling of leaves. Water soaked areas with pale green colour develop from the leaf margin inwards, which later become dark brown. Unlike soft rot of ginger, the stem can’t be pulled out easily. Milky ooze of bacteria can be seen from cut end of tillers. The bacterium is fast splashed and spread with water. The damage inflicted upon the roots of these crops sometimes by excessive soil moisture, cause more leakage of the root exudates and create entry points as well as favourable environment for growth and development of the pathogen along with secondary infections. Management aspects includes: i) proper drainage ii) use disease free seeds iii) soil and seed treatment with bio formulations of T. harzianum and Pseudomonas fluorescence. iv) seed treatment with 1% Bordeaux mixture and subsequent sprays at 15 days interval. Head rot of cauliflower and cabbage, caused by Erwinia carotovora intensify during the wet period. Water help in dispersal of the bacterium and injury to the curd/head aggravates the disease. Infection starts on the petiole in contact with soil. Infected head is watery and has a complete head rot. Affected area is soft, mushy, turns brown and emits foul odor. Judicious use of water can help to contain the disease. Management of the disease is also done with i) use of certified seeds ii) hot water treatment of seed at 500 C for 30 min. 83
Fungal diseases: Late blight of potato and tomato caused by Phytophthora infestans is directly correlated with soil moisture and atmospheric humidity. Water soaked spots usually first appear at the edges of the lower leaves which enlarge rapidly and form brown blighted areas. On the undersides of the leaves, a zone of white fungal growth appears at the border of the lesions. Under continuously wet conditions, all tender, above ground plant parts blight and rot, giving off a characteristic odour. In dry weather the disease does not develop. Affected tubers bear purplish or brownish blotches which later become firm, dry and somewhat sunken. The rot continues to develop after the tubers are harvested. Tomato fruit is attacked and may rot rapidly in the field or in storage. The disease development can be checked with judicious water use based on the prevailing weather conditions. Management steps also include: i) use disease free seeds ii) follow sanitary measures, destroy and burn crop residue and collateral hosts. iii) soil and seed treatment with bio formulations of T. harzianum and Pseudomonas fluorescence. iv) seed treatment with 1% Bordeaux mixture and subsequent sprays at 15 days interval. Soft rot caused by Pythium aphanidermatum is the most destructive disease of ginger. The fungus perpetuates fast under excess of soil moisture and less of oxygen.
Diseases of fruit crops Mandarin is indigenous to this region and presently an important commercial fruit crop of the state. Diseases play a major role in the success of a mandarin orchard. Apart from the congenial climatic conditions for pathogen build up, other faulty management practices predispose the crop to diseases. Many of the diseases which affect the crop are: Fungal diseases: a. Acrosporium tingitanimum – powdery mildew b. Phytophthora parasitica and P. palmivora - gummosis c. Septobasidium pseudopedicellatum – felt disease d. Pellicularia salmonicolor - pink disease e. Diplodia natalensis - diplodia gummosis f. Elsinoe fawcetti – scab disease Excess of soil moisture and high humidity predispose citrus plants to most of the fungal diseases. Bacterial diseases: Xanthomonas campestris pv. Citri causing citrus canker primarily rely on wind or water (splash) dispersal in order for populations to move to new hosts. Bacterial colonization of host plants requires the entry of the pathogen into host tissues, most commonly through natural openings in the plant such as stomata, lenticels, or wounds on the plant surfaces.
Diseases of flower crops Rose: Free water on foliage inhibit the fungi that cause powdery mildew of roses (Sphaerotheca pannosa) and other plants. Earlier best managed with the cultural method of misting the plants in green houses. Marigold: Collar rot occurs in nursery stage and grown up plants depending upon the soil types and moisture conditions. Some other fungal diseases such as Damping Off caused by Pythium sp., Leaf spot caused by Alternaria spp., Cercospora spp. etc., Blight caused by Colletotrichum capsici, Bud rot caused by Alternaria dianthi are also related to the moisture conditions. Orchids: Orchids fall prey to a number of diseases causing organisms such as fungi, bacteria, virus etc. Peak incidence of the diseases is observed during wet season. Heart rot caused by Phytophthora is a 84
serious disease which destroys plants at various stages of growth. Pythium also causes similar damage.
Disease Management • •
Proper drainage and raised beds are a must for management of nursery diseases. Formulations Trichoderma harzianum and T. viridae can be used for seed and soil treatment as well as foliar application against the fungal pathogens. • Pseudomonas fluorescence is most effective against most bacterial pathogens. • Crop rotation should be followed for starving the pathogens and declining their population. • One percent Bordeaux mixture can be applied as root dip, soil drench and foliar spray. • Bordeaux paint applied on the trunk and pruned wounds of citrus prevent pathogens attack. • One part milk diluted with nine parts of water work wonders in reducing disease incidence and progress of powdery mildew. Water conservation methods like zero tillage, bunding, mulching etc. helps better water management, prevents disease development and spread, resulting in the achievement of potential yield. Strategies should also be made to mitigate the climate change with adoption of proper technologies so as to produce more crops per drop of water.
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Important varieties in the context of climate change Kolom Rabi Introduction Traditionally farmers have domesticated improved and conserved thousands of crop species and varieties, using their traditional knowledge. This diversity has value in itself in the face of uncertainty. In addition, traditional varieties or landraces are more genetically diverse than modern varieties and so are better able to withstand environmental stress such as lack of water or nutrients. Laboratory analysis has shown that in situ varieties have much higher genetic diversity than those held ex situ for 30 years, which shows the positive influence of environmental factors and farmers. Coastal areas and forest conserves plant and animal biodiversity which provides a valuable source of germplasm for species that can tolerate the current extreme weather and soil conditions including drought, floods, salt, pest and disease tolerance. The diversity of traditional varieties sustained by farmers around the world is increasingly valuable for adaptation as climate changes, particularly as modern agriculture relies on a very limited number of crops and varieties. Here lies the need for collection, conservation and management of the these local germplasms of crop varieties for their utilization in present day crop improvement programmes and develop certain varieties utilizing the gene pool available to sustain crop production and productivity in the context of the prevailing climate change and aberrant weather conditions.
Variety A variety refers to a genotype or group of genotypes which has been released for commercial cultivation either by State Variety Release committee (SVRC) or Central Variety Release Committee (CVRC) and notified by the government of India. A variety is also termed as cultivar (cultivated variety). A variety has three important characteristics viz., (a) distinctiveness, (b) uniformity and (3) stability. In other words, the variety should remain unchanged in its distinctiveness and uniformity for reasonable period of time when reproduced or reconstituted (hybrid).
Norms for a variety There are certain norms for varieties besides distinctiveness, uniformity and stability (DUS characters) and the new variety should be superior to the previously released varieties of a crop in one or more of the following characteristics. • Yield potential of grain, oil fiber, fodder, vegetable or other economic products. • Resistance to biotic (disease, insects, and parasitic weeds) and abiotic (drought, salinity, frost, cold, heat, metal toxicity etc.) stresses. • Quality of oil, fiber, protein, fodder, vegetables, grain etc. • Maturity duration (earliness) • Adaptability: Suitability for general cultivation over a wide environment. • Suitability for machine harvesting etc.
Promising varieties for Dimapur district, Nagaland (i) Promising rice varieties for Dimapur district, Nagaland: Sl. No. Variety Plant height (cm) Duration (days) 1 Wonder rice 158.18 166 2 IET-16313 123.80 135 3 Shahsarang-1 108.54 135 86
Average yield (q ha-1) 55.0 52.0 47.4
4 5 6 7 8 9 10
RCM-11 RCM-5 RCM-9 RCM-20 Ranjit Teke Bhalum-1
129.50 140.72 110.75 106.10 114.4 113.78 108.77
127 139 140 136 145 135 143
46.0 45.7 45.6 45.2 42.6 31.4 35.2
Wonder rice
IET 16313
Shahsarang-1
RCM-11
RCM-5
RCM -9
Ranjit
Teke
Popular rice varieties developed by CAU, Imphal: Sl No. Varieties Plant height (cm) Crop Duration (days) 1 CAU R1 123.5 138 2 CAU R3 85.67 102
CAU R1 at Seithekima A village
Yield (q ha-1) 47.68 25.18
CAU R3 at ICAR Farm
(ii) Promising maize varieties for Dimapur district, Nagaland:
All rounder
DMH 849
87
HQPM-1
Sl No. Hybrids 1 2 3 Composites 4 5 6
Variety
RCM-76
DA 61 A Plant height (cm)
Grain yield (q ha-1)
All rounder DMH 849 HQPM-1
237.54 242.67 227.67
37.81 33.45 31.27
DA 61 A RCM 76 Vijaya composite
244.34 261.42 218.83
23.41 21.16 20.08
(iii) Promising oilseed varieties for Dimapur district, Nagaland Sl. No. Varieties Kharif/ rabi Toria 1 M-27 Rabi 2 TS -38 Rabi 3 TS-76 Rabi Soybean 1 JS-335 Kharif 2 MAUS-71 Kharif 3 JS-9560 Kharif Linseed 1 Neelam Rabi 2 Garima Rabi 3 Parvati Rabi 4 Subhra Rabi 5 Sharda Rabi Groundnut 1 ICGS 76 Kharif/ rabi 2 JL-24 Kharif Sesame 1 AST-1 Kharif 2 Local Kharif
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Average yield (q ha-1) 8-12
23-28
8-13.5
16.65-18.5
8.63-10.5
(iv) Promising pulse varieties for Dimapur district, Nagaland Sl. No. Varieties Kharif/ rabi Black gram 1 PANT -U -19 Kharif 2 KU-301 Kharif Green gram 1 Pratap Kharif Lentil 1 K-75 Rabi 2 IPL-81 Rabi 3 DPL-62 Rabi Pigeon pea 1 UPAS-120 Kharif 2 BRG-2 Kharif
Soybean var. JS 335
Black gram var. KU 301
Lentil var. K-75
Average yield (q ha-1) 8.24-12.5
7.88-10.2 6.0-7.5
14.35-25.2
Green gram var. Pratap
Varieties suitable under different climatic variabilities a) Drought tolerant or resistant varieties released in India: Breeding for drought resistance is an important objective of plant breeding programmes in many crops. In India about 73.5% the agriculture is represented by dry land farming. In the rainfed areas, crops generally suffer from drought at one or the other stage. Hence, breeding work on drought resistance is carried out in almost all the International and National Crop Research Institutes. In India, drought and salinity resistant or tolerant varieties have been developed in several crops. Sl. No. Name of Crop Drought Tolerant Varieties 1 Sugarcane CoS 510, Bo1, Co1148, Co449, Co997, Co1158, Co62175 and Co6907. 2 Bread Wheat NP4, NP720, Pb9-D, C217, C281, K46, RS 31-1, Ao88, Ao113, Ao115. 3 Durum Wheat Motia, Gulab, Jay, Vijay, Arnej. 4 Cowpea IGFRI 437, IGFRI 450 5 Rice Akashi, Sahbhagi Dhan, Pusa 1121, Kalinga & BR 34 6 Cotton MA9, MCU10 7 Barley Karan 280 8 Groundnut Jyoti, DH3-30 9 Sunflower EC 68414, EC 68415 10 Bajara BJ 104 b) Flood tolerant rice varieties in India: Submergence can affect rice crops at any stage of growth, either short-term (flash floods) or long-term (stagnant flooding). The chances of survival are extremely low when completely submerged during the crop’s vegetative stage. Plant breeders have discovered that a single gene, the SUB1 gene, confers resistance to submergence of up to 14 days. Improved varieties incorporated 89
with the SUB1 gene have shown a yield advantage following flooding for 10–15 days. Floodtolerant varieties that have been released and are now being planted include Swarna Sub1 in India, Samba Mahsuri in Bangladesh, and IR64-Sub1 in the Philippines. Sl. No. Rainfed Shallow lowlands Semi deep to deep low lands 1 Swarna Sub-1 Varshadhan 2 Pooja Durga 3 Swarna Sarala 4 Hanseswari In India, breeding work for salinity resistance is mainly carried out at Central Soil salinity Research Institute, Karnal (Haryana). Several salt resistant varieties of rice, barley, wheat and sugarcane (CO453 and CO62175) have been released. Soil salinity is a serious problem throughout the world in some areas. Hence breeding work on salt resistance is carried out in all important International and some National Crop Research Institutes. Salt resistant variety of rice has been released from Indonesia and that of wheat from china. In India, salinity resistant varieties have been developed in sugarcane, okra, rice, onion, and barley. c) Salinity tolerant crop varieties released in India: Sl. No. Name of Crop Varieties 1 Rice CSR-49, CSR 36, CSR 30 (basmati type), CSR 27, CSR 23, CSR 13 and CSR 10 For coastal regions:- Butnath (CSRC(S) 5-2-2-5) and SumatiCSRC-CSRC(S) 2-1-7 2 Wheat KRL 213, KRL 210, KRL 19 and KRL 1-4 3 Indian Mustard CS 56, CS 54 and CS 52 4. Chick pea (gram) Karnal Chana 1 5 Dhaincha(Sesbania) CSD 137 and CSD 123 6 Sugarcane Co453, Co997, Co62399, Co7717, C01149, CoS767 and Bo 91. 7 Okra Pusa sawani 8 Rice Mohan 9 Onion Hisar 2 and Punjab selection 10 Barley Ratna, RS6, Karan 18. d) Acid tolerant maize varieties for the NEH region: Effect of low pH or acidity in lowland paddy doesn’t affect the crop growth and yield but in case of maize acid tolerant varieties can perform better in terms of yield and other quantitative characters which can be diagnosed by application of lime which applies for other crops also. Most of the hybrids composite varieties of maize released by ICAR Research Complex are either acid tolerant or resistant varieties which are listed below. Sl. No. Varieties 1 DA 61 A 2 RCM 76 3 RCM-75 4 Vijaya composite
Case studies (a) Toria and linseed cultivation as second crop after paddy using residual moisture: Cultivation of toria and linseed as second crop utilizing the residual moisture in the field after the harvest of early to medium duration paddy varieties has proved to be a solution for those areas which remains fallow after the harvest of long duration paddy varieties. Moreover linseed does not require much irrigation and can perform well with little residual moisture present in the field after the paddy crop is harvested which can also be sown as Utera crop. 90
Toria (TS 38) as Toria var. M-27 under Linseed variety Sharda Linseed var. Parvati second crop after NICRA project at Seithekima A paddy village (b) Pre- kharif, kharif/ winter maize cultivation: Cultivation of maize wherever lowland paddy cultivation is not possible or delayed due to late onset of monsoon rains and drought like situations in the district. Introduction of hybrids like HQPM-1 and other composite varieties like Vijaya Composite, RCM-75, RCM-76, DA -61A which are high yielders with a productivity of 4-5 t ha-1 in case of hybrids and 2.5-3 t ha-1 in case of the composites provide an opportunity to cultivate maize whole round the year i.e., Pre-kharif, Kharif and as Winter maize.
Pre-kharif maize at Seithekima A village Winter maize at Bade village (c) Sesamum cultivation to mitigate crop loss due to shortage of rainfall: Lowland paddy growing areas along the Dhansiripar Block of Dimapur district has been greatly affected by drought like situations forcing the farmers to change the cropping pattern in the district and they started cultivation of Sesamum variety AST-1 and other local varieties available in the local market which proved to be an alternative crop for areas affected by late onset of monsoon with minimum yields of 10-12 q ha-1 and a gross income of Rupees 75,000 to 80,000 per hectare annually.
(d) Introduction of upland paddy under lowland moisture stress condition: Elevated lowland paddy fields where paddy cultivations were practiced earlier and due to moisture stress conditions without irrigation facilities available farmers are compelled to stop paddy cultivation. KVK Dimapur introduced upland paddy varieties in those areas which were sown directly in lines during the months of April to May in dry condition which when receives late monsoon rain and gets germinated without any single irrigation. Weeding is done with spade once or twice and fertilizers were applied at recommended doses. The crop is grown totally rainfed which can be harvested earlier than the normal lowland paddy varieties yielding at an average of 3.2 to 3.8 t ha-1 during the months of August to September giving enough scope and time for raising the next crops like toria, linseed or wheat with enough residual moisture in the field along with vegetable crops in the winter 91
season. These upland paddy varieties will prove to be a tool for mitigating moisture stress in lowland paddy cultivated areas of Peren and Dimapur districts of Nagaland.
SARS -2 at maturity stage in Dhansiripar village
SARS-5 at maturity stage
RCM-5 in Dhansiripar village
Varieties Plant height Crop Duration (Days) Yield (q ha-1) RCM-5 109.54 124 38.4 CAU -R2 108.26 101 32.7 SARS -1 122.72 131 34.3 SARS -2 114.26 132 33.47 SARS -5 112.6 135 36.19 (e) Intercropping of turmeric & jhum paddy in pineapple orchard: Normally pineapple orchards start bearing after 18 months of planting and farmer doesn’t get any type of income out of the pineapple farm between planting to fruiting period. Looking into this, efforts were made to generate additional income during the pre- bearing stage of the pineapple by utilizing the space available between the two rows of pineapple through intercropping with turmeric, Jhum paddy, lemon /orange. Through intercropping with other crops suppresses the weed growth along the pineapple rows reducing the cost of weeding during the first year of planting when the weed growth is very fast due to high rainfall conditions. To improve and exploit the full potentiality of this system of intercropping in pineapple orchards KVK Dimapur introduced the method of planting pineapples across the slope in double row spacing’s of 90 cm x 60 cm x 30 cm (checks soil erosion) intercropped with Megha Turmeric-1 variety of turmeric/ Jhum paddy, lemon/ orange and planting of banana along the border of the fields which ensures sustained crop production in case of failure of a particular crop with additional income out of the unit area.
Intercropping of turmeric with pineapple
Intercropping of jhum (upland) paddy with Pineapple
Intercropping of lemon/ orange with pineapple
New projections a) Inter varietal crossing programme on rice genotypes at the centre: Inter varietal crossing programme of rice genotypes consisting of Wonder Rice (Guinness Book of World Records holder for World’s Tallest Rice) as female parent with RCM – 20, Shahsarang-1 and IET – 17278 as male parents were carried out at the research farm of ICAR Research Complex for NEH Region, Nagaland Centre whose F8 seeds are ready as varietal improvement programme of this centre. Some of the lines proved to be early to medium duration lines which after their release can be incorporated in enhancing cropping intensity and cropping sequences in the state. 92
Extra early F7 generation lines
Medium duration F7 generation lines
b) Upland paddy breeding programme: An inter-varietal crossing programme on local upland paddy Germplasms collected from different districts of Nagaland as upland paddy varietal improvement programme has been conducted at the centre and F6 seeds are ready for further generation advancement. Average normal soil moisture content for upland paddy cultivation ranges from 25-30 % in field conditions and some of the lines showed resistant or tolerant to extreme moisture stress conditions which can thrive well at a soil moisture content of 7.32 % and below in the field. Such lines or crosses will prove to be drought tolerant or resistant lines which after further evaluation and multiplication trials can be utilized effectively for moisture stress conditions.
F6 generation upland paddy improvement plot
Upland paddy cross (Epyo Tsuk x RCM-5)
Upland paddy line thriving well at 7.32 % soil moisture content
c) Participatory rice breeding: Rice seed exchange programme along with farmers led rice cultivar development in Nagaland has been initiated in collaboration with GIZ (German) and NEPED under Climate change adaptation, North Eastern region (CCA-NER) project in collaboration with SASRD, NU, Medziphema and KVK Dimapur, ICAR Research Complex for NEH Region, Nagaland Centre. This programme emphasizes on exchange or local rice germplasms among the farmers of different villages and districts and development of farmer bred rice varieties in the state through crossing of local paddy germplasms across elevations and agro ecological systems to develop varieties which can perform under adverse agro climatic situations arising out of climate change. Rice crossing programme have been initiated among the farmers which after multi-location testing’s may put for zone specific recommendations for mitigating the climate change in an effective way through locally available material and resources.
Training programme on rice breeding 93
Farmer breed F1 seeds
Conclusion Utilization of crop variety resistant or tolerant to biotic (disease, insects, and parasitic weeds) and abiotic (drought, salinity, frost, cold, heat, metal toxicity etc.) stresses doesn’t merely mitigate the losses in food grain production and productivity. Instead the particular crop variety or varieties should be tuned in such a way that it shows its maximum potentiality when they are subjected to combinations of different crop varieties in crop/cropping system based technologies, resource conservation-based technologies and socio-economic and policy interventions. Changes in climate can be expected to have significant impacts on crop yields through changes in temperature and water availability in coming years. The purpose of mitigation and adaptation measures is therefore to attempt a gradual reversal of the effects caused by climate change and sustain development. There are several mitigation and adaptation practices that can be effectively put to use to overcome the effects of climate change with desirable results and development and use of appropriate varieties at appropriate place and time can help attain sustainability of crop production in near future to come.
References and further reading Abdul FR, Ramya KT, Amit K, Avinash P, Ahmed H, Singh S, 2011. Rice in North Eastern Hills. Division of Plant Breeding, ICAR Research Complex for NEH Region, Umiam, Meghalaya. http://www.cssri.org/index.php?option=com_content&view=article&id=135&Itemid=139 Munda GC, Bujarbaruah KM, Hazarika UK, Panwar AS, Patel DP, Rajesh K, Das A, Singh IM, Viswakarma AK, Mitra J, 2006. Technology for Oilseeds Production in NEH Region. ICAR Research Complex for NEH Region, Umiam, Meghalaya. Pattanayak A, Bujarbaruah KM, Sharma YP, Ngachan SV, Dhiman KR, Munda GC, Azad NS, Satpathy KK, Datta KK, Prakash N, Premila D, Viswakarma AK, 2006. Steps towards optimizing rice production in North East India. ICAR Research Complex for NEH Region, Umiam, Meghalaya. Singh P, 2005. Essentials of Plant Breeding. Kalyani Publishers.
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Contingency planning in climate change scenario Sanjay Kumar Ray Introduction Climate change and its variability are emerging as the major challenges influencing the performance of Indian agriculture. Climate change impacts directly and indirectly in agriculture production system. The magnitude of impacts may vary depending on the degree of change in climate, geographical region and type of production system, where the productivity may be decreased drastically in some major crops like wheat, rice and maize. Variability in temperature due to climate change may affect directly on reproduction, pollination and fertilization processes, of some important crops and indirectly by increasing the pest and disease incidences. Cultivation practice of Nagaland is mainly rainfed and livelihood of more than 70% population, is depends on rainfed agricultural practices. Climate change is negatively effecting rainfed agriculture production, primarily due to temperature and rainfall variability and reduction in number of rainy days (Venkateswarlu and Shanker, 2012). Out of the total geographical area (16579 sq. km) of the state, only 8.48% of the area is plain and the rest 91.52% is constituted by undulating and hilly terrain (Anonymous, 2014), where the sowing and early crop growth is totally depends on the distribution of per-monsoon rainfall and mid to terminal crop growth is rely on normal monsoon. From last two decades, the frequency and intensity of extreme weather events likes drought, delay of pre-monsoon, delay normal monsoon and early withdrawal of south west monsoon and number of intermittent long dry spells are realizing due to global warming, which causes severe hazard to production system of hill agriculture of Nagaland. In this scenario, the preparation of a suitable contingency plan for different stages of crops and cropping pattern is very much needed to reduce the potential risk of climate variability by adoption appropriate resource conservation technologies for different stages of crop growth (before and after) to counter or combat the threats (drought, temperature variation, delay pre-monsoon, delay normal monsoon, sudden breaks in between monsoon, early withdrawal of monsoon and delayed withdrawal of monsoon) against climate change.
General short term contingency plan for rainfed and irrigated agriculture (a) Rainfed: • Alternative crop or variety or cropping pattern in view of the delay in monsoon and shortening of the growing period, including delay in sowing of nurseries in case of paddy. • In case of normal onset followed by early season droughts re-sowing may be recommended including variety seed rate etc. • In case of early or mid season dry spells, need to be adopted the crop management techniques to save standing crop. • In case of terminal drought indicate giving life saving supplemental irrigation, if available or taking up harvest at physiological maturity with some realizable grain/fodder yield etc. • Agronomic practices which help in coping with late planting like increased or decreased spacing, changes in planting geometry, intercropping in case of sole crops, thinning, mulching, spray of anti-transpirants or other chemicals, supplemental irrigation, soil and moisture conservation practices like ridging, conservation furrows, mulching etc. • In case of terminal drought indicate early rabi cropping with suitable crops/varieties with a possibility of giving pre-sowing/come up irrigation etc. • Details on the source of the breeder seed, in case an alternate crop or variety should be suggested. Possible convergence needed with ongoing central or state schemes like RKVY, 95
NFSM, etc., to meet the cost of materials, labour or implements etc. to carry out any field based activity quickly. (b) Irrigated: • Normal crop or cropping systems grown in a given irrigated situation. Need to be suggest change in the crop, variety or cropping system in view of delay in release of irrigation water, less water availability etc., • Agronomic measures like improved methods of irrigation (skip row etc.), micro irrigation (drip/sprinkler/sub-surface), deficit irrigation, limited area irrigation, mulching etc, that improve water use efficiency and make best use of limited water including methods of ground water recharge and sharing. • Source of availability of seed of the alternate crop or variety, and details of state or central schemes like National Rural Employment Guarantee Scheme (NREGS), Rashtriya Krishi Vikas Yojana (RKVY), National Food Security Mission (NFSM), Integrated Scheme on Oilseeds, Pulses, Oilpalm and Maize (ISOPOM), etc., which facilitate implementation of the agronomic measures suggested.
Crop wise strategies for weather related contingency plan (drought) (a) Situation: Upland rainfed (i) Delay by 2 weeks (April 3rd week) ConditionNormal crops early season grown (15th Change in drought March to 1st crop/variety (delay onset) April) Var-Vandana, Delay by 2 Jhum paddy Bhalum-4, weeks (April IURON 3rd week) Maize No change
Rajma/Kholar Naga dal (Rice bean) Ginger Turmeric
Suggested Contingency measures Dry sowing 8-10 days before rains with 1520% higher seed rate for local varieties.
No change No change
Seed soaking, Dry sowing 8-10 days before rains with 15-20% higher seed rate for local varieties Seed soaking (18 hours soaking in water followed by 24 hours shade drying)
No change No change
Mulching with locally available weed/biomass Sowing in ridge furrow
(ii) Delay by 4 weeks (May 1st week) ConditionNormal crops early season grown (15th Change in Suggested Contingency measures drought March to 1st crop/variety (delay onset) April) Variety: Dry sowing 8-10 days before rains with 15Jhum paddy Bhalum-3 & 4, 20% higher seed rate. Reduced nutrient SARS-1 & 2 application Reduced nutrient application, Dry sowing 8Delay by 4 Variety: DA Maize 10 days before rains with 15-20% higher seed weeks (May 61A, RCM-76 rate. Sowing in ridge furrow. 1st week) Rajma/Kholar No change Seed soaking (18 hours soaking in water Naga dal (Rice followed by 24 hours shade drying) No change bean) Sesame Variety: RT-46 Dry sowing 8-10 days before rains with 1596
20% higher seed rate. Ginger Turmeric Colocosia
No change No change No change
Mulching with locally available weed/biomass Sowing in ridge furrow
(iii) Delay by 6 weeks (May 3rd week) Conditionearly season drought (delay onset)
Normal crops grown (15th Change in Suggested contingency measures March to 1st crop/variety April) Jhum paddy
Soybean Replace maize and go for Maize Soybean/ groundnut Delay by 4 Rajma/Kholar Cowpea weeks (May (variety: UPCNaga dal (Rice rd 287 KBC-1 & 3 week) bean) 2, TVX-944) Ginger No change Turmeric
No change
Sowing in ridge furrow method Sowing in ridge furrow method
Seed hardening (18 hours soaking in water followed by 24 hours shade drying) Mulching with locally available weed/biomass, Sowing in ridge furrow method, Adopt pro-tray transplanting method for ginger & turmeric,
(iv) Pre monsoon normal followed by 15-20 days dry spell after sowing Condition Suggested Contingency measures Early crop Normal sowing Soil nutrient & moisture season (15th March to Crop management conservation 1st April) drought Normal onset Jhum paddy Re-sowing if germination Spray pesticides, mulching followed by percentage less than 50%, weeding 15-20 days dry spell Maize Re-sowing or gap filling, Provide life saving irrigation (if thinning, inter culture possible), Adopt intercropping after sowing leading to operations, weeding by hand with short duration legume hoe oilseeds in place of sole poor germination/ cropping. Rajma/ Kholar Gap filling after seed Foliar spray 0.5% KCl & 2% crop stand Naga dal (Rice soaking, weeding by hand DAP either morning or evening bean) hoe, thinning if necessary, Foliar spray pesticides to control pest and diseases Ginger Weeding Mulching in between rows with Turmeric Weeding locally available weed/biomass
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(v) Pre monsoon normal followed by mid season drought at vegetative stage Condition Suggested Contingency measures Normal Mid sowing (15th season Crop management Soil nutrient & moisture conservation March to 1st drought April) Thinning, inter-culture Postponed top dressing (N) & provide operation, use field weeds additional N @ 10 kg ha-1 at next rain, Jhum paddy as mulch, Make ridges Foliar spray 1% Urea & KCl, Foliar every after 5-7 m across spray of Zn-EDTA @ 0.5% the slope Thinning, inter-culture Provide life saving irrigation 5 cm (if operation, use field weeds possible), delayed top dressing, Foliar as mulch, Foliar spray Vegetative Maize spray 0.3% urea & KCl either morning stage of pesticides to control pest or evening, soil mulching, apply 15 kg and diseases, Apply kaolin crop more N after receiving rain anti-transpirant (4%) (Long dry Rajma/ Foliar spray 1% urea & KCl at spell) Kholar morning or evening, use antiWeeding, thinning if transpirants like kaolin @ 7.5 ml/100 Naga dal necessary, grazing leaf tip ml water and salcylic acid @ 1g/1lit (Rice bean) water either during morning or evening hours. Ginger Mulching with locally available Weeding Turmeric weed/biomass, earthing up (vi) Pre monsoon normal followed by mid to late season drought at flowering/fruiting Condition Suggested Contingency measures Mid to late Normal sowing Soil nutrient & moisture season (15th March to Crop management conservation st drought 1 April) Foliar spray 1% urea & 0.5% Weeding & inter-culture boron either morning or Jhum paddy operation to creat soil mulch evening, Foliar spray of ZnEDTA @ 0.5% Weeding & inter-culture Remove alternate row for operation, Foliar spray fodder, Provide life saving Flowering/ Maize pesticides to control pest and irrigation (if possible), Foliar fruiting stage diseases, Apply kaolin anti- spray 1% urea & 0.5% boron at of crop transpirant (4%) morning or evening (Long dry Rajma/ Kholar Foliar spray 1% urea & 0.5% spell) boron at morning or evening, Naga dal (Rice Weeding Provide life saving irrigation (if bean) possible) Ginger Weeding & earthing up Mulching with locally available weed/biomass, Plant protection Turmeric Weeding & earthing up measures for stem borer and aphids
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(vii) Terminal drought (Early withdrawal of monsoon) Condition Suggested Contingency measures Normal Terminal sowing (15th Soil nutrient & moisture Crop management drought March to 1st conservation April) Inter-culture operation to Foliar spray 1% urea & 0.5% boron Jhum paddy creat soil mulch at morning or evening Weeding, inter-culture Provide life saving irrigation (if operation to creat soil possible), Harvested green cob of Maize Early mulch, Apply kaolin anti- maize. Planning for sowing garden withdrawal of transpirant (4%) pea, French beans as pre-Rabi crops monsoon Rajma/ Kholar Weeding, Foliar spray Naga dal (Rice pesticides to control pest Provide irrigation if possible, Foliar bean) and diseases spray 1% urea & 0.5% boron at Ginger Harvested at physiological morning or evening, Turmeric stage (b) Situation: Valley lowland /TRC / WTRC rainfed (i) Delay by 2 weeks (June 3rd week) Condition-early Normal sowing season drought (June 1st Change in crop/variety (delay onset) week) Prefer medium duration variety: WTRC/ lowland paddy RCM-9 & 11, Shahsarnag-1 Soybean No change Delay by 2 weeks Groundnut (June 3rd week)
No change
Brinjal
No change
Chilly
No change
(ii) Delay by 4 weeks (July 1st week) ConditionNormal Change early season sowing (June drought (delay st crop/variety 1 week) onset)
Delay by 4 WTRC/ weeks (July lowland 1st week) paddy
in
Suggested Contingency measures Transplant 2-3 seedling per hill, Supplement sufficient amount of organic manures Pre soaking the seeds for proper germination, adopt minimum or zero tillage sowing to best use of residual moisture Decrease spacing, Provide adequate amount of neem cakes and organic manure in pit Decrease spacing, Provide adequate amount of organic manures
Suggested Contingency measures
Transplant 4-5 seedling (30-35 days) per hill, Adopt water saving system of rice Short duration intensification (SRI) practice, Prefer direct Variety: seeding by using paddy drum seeder in place of Nagaland special, transplanting, Aerobic rice with Bhalum-3 & RCM-5, BhalumRCM-5 variety to save water and time, 3 Supplement sufficient amount of organic manures 99
Soybean
JS-335, JS-93-05
Groundnut
TMV-2, JL-24
Brinjal
No change
Chilly
No change
Soaking of seeds in water for 18 hours, followed by 24 hours shade drying, Provide adequate amount phosphatic fertilizers, prefer ridge furrow system for sowing Decrease spacing, Provide adequate amount of neem cakes and organic manure Decrease spacing, Provide adequate amount of organic manure
(iii) Monsoon normal followed by mid season drought at vegetative stage Condition Suggested Contingency measures Mid season Normal sowing drought Soil nutrient & moisture (June 1st Crop management conservation (Long dry week) spell) Use proper bunding to save Remove weeds to conserve water, Postpone top dressing (N) soil moisture and reduce WTRC/ & provide additional rain at next competition to main crop, lowland paddy rain, provide life saving Azolla application @ 300 g irrigation (if possible), Foliar sqm-1 spray of Zn-EDTA @ 0.5% Weeding, earthing up, Spray urea and DAP @ 2% at Vegetative Soybean Foliar spray pesticides to morning or evening if crop stand stage to control pest and diseases appears poor flowering Groundnut Weeding, earthing up stage Weeding, Foliar spray Use mulching to conserve Brinjal pesticides to control pest moisture, Provide life saving and diseases irrigation (if possible), use antitranspirants like kaolin @ 7.5 Weeding, Foliar spray ml/100 ml water and salcylic Chilly pesticides to control pest acid @ 1g/1lit water either and diseases during morning or evening hours.
Strategies contingency plan for Rabi crops Crop Mustardrapeseed Vegetable Mustrad Wheat Linseed
Suggested contingency measures Sowing Vegetative stage Flowering stage Minimum tillage sowing, Sow pre-soaked seeds Provide one irrigation if possible immediately after harvest (kharif) Zero tillage sowing to best Provide mulching, Weeding use of residual moisture Sow immediately after Provide one irrigation if Provide one irrigation if harvest (kharif) by zero possible (Active possible (before tillage (ZT) method, tillering) flowering) Sow pre-soaked seeds in ZT Weeding, Provide one irrigation (5 cm) if possible method 100
Prefer early variety (Arkel Weeding, Mulching, Provide one irrigation (5 cm) & contender), Sow preif possible, Foliar spray of 1% urea & 0.5% of B soaked seeds for pea
Pea, beans
Provide 2-3 irrigation Nursery under shade, Use Provide 1-2 irrigation, followed by N fertilizer, Foliar spray of 1% urea organic manure in pit, plant apply pesticides, on bed & 0.5% of B Mulching, weeding, Planting on ridge, Use Provide 2-3 irrigation followed by N fertilizer, organic manure in pit, Mulching, weeding, Foliar spray of 0.3% Mo & Nursery under shade 0.5% of B for 3 times
Tomato
Cauliflower Cabbage,
Strategies for unusual rains (untimely, unseasonal etc.) for both irrigated and rainfed situation (i) For important field crops Condition Crop
WTRC Rice
Mustard
Sesame, wheat, pulses Sugarcane
Turmeric
Vegetative stage Drain excess water, postpone top dressing N fertilizers still water recedes, take up the gap filling either with the available nursery or by splitting the tillers from the surviving hills Drain out excess water, inter cultivation at optimum moisture condition to loosen and aerate the soil and to control weeds Do
Continuous high rainfall in a short span Suggested contingency measures Flowering stage Crop maturity stage Drain excess water, Spray 2% brine Apply the solution to prevent recommended premature nutrients after germination in draining excess field, Allow the water crops to dry completely before harvesting
Post harvest Drain the excess water and spread sheaves loosely in the fields or on field bunds where there is no stagnation, Dry the grain to proper moisture content before bagging and storage.
Drain excess water, inter cultivation at optimum moisture condition to loosen and aerate the soil and to control weeds
Drain out excess water, Allow the crops to dry completely before harvesting
Dry the grain to proper moisture content before bagging and storage.
Do
Do
Do
Drain out excess Drain out excess water, proper water, bunding Drain out excess Drain out excess water, gap filling to water, Need plant replace rotten protection seedlings measures
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Harvest physiological maturity
at Shift to safer place to maintain the quality
Harvest physiological maurity
at Keep the harvested produce in shed for aeration
(ii) For important vegetables and fruits Condition Continuous high rainfall in a short span Suggested contingency measures Crop Crop Vegetative stage Flowering stage maturity stage
Post harvest
Cauliflower,
Drain out excess water, Three sprays of 0.1% ammonium molybdate 15, 30 & 45 days after transplanting
Drain excess water, Blanching i.e, covering the curd through tying the outer leaves up over the curd improves curd colour and quality.
Drain out excess water, Harvest the produce on a clear sunny day
Leaving only sufficient jacket leaves to protect the curd from other mechanical injury in transport
Cabbage, Brinjal
Do
Do
Do
Do
Market the Drainage,Vines of Chilly, Okra Drain out excess water , produce as cucurbitace should be & other Need based plant soon as staked along elevated vegetables protection measures possible if fames at maturity Drain excess water, Harvest the produce on Potato Drain out excess water Drain excess water a clear sunny day after the water recedes Drain out excess water Drain out within 24 hours, Drain out excess water excess water Banana immediate light hoeing within 24 hours within 24 after drainage of water hours Drain out excess water of Market the within 24 hours, Spray Application produce as 1% KNO3 or Urea@ hormones/nutrient 2% solution 2-3 times, sprays to prevent flower soon as Other Fruits cut down the infected drop or promote quick possible if branches and apply flowering/fruiting at maturity bordeaux mixture
Shift to safer place to maintain the quality, market
Keep the harvested produce in shed for aeration to maintaining the quality of product Shift to safer place maintaining the quality Keep the harvested produce in shed for aeration to maintain the quality of product
Conclusion Buffer stock of drought tolerant, short duration crop varieties will provide an opportunity for farmers to diversity, which will be allowing them to counter the threat against climate change. Adoption of mixed or inter cropping cultivation practices approach rather than monocropping, will reduce vulnerability to climate change and variability will reduce the risk of crop failure. Improved farming technologies, such as efficient irrigation system, provide opportunities to reduce direct dependence on natural factors likes precipitation and runoff. Conservation agriculture practices viz. 102
conservation tillage, mulching, thinning, furrow digging and contouring will protect the fields from water erosion, and can also help to retain moisture by reducing evaporation and increasing water infiltration. The knowledge of scientific package of practices can also be provided to farmers through hands on training and demonstration for their crop planning and irrigation scheduling during drought.
References and further reading Anonymous, 2014. http://nagaland.nic.in/Notification/Microsoft%20Word%20-20Integrated% 20agriculture%20paper%20190112_Nagaland.pdf. Accessed 12th January 2015. Venkateswarlu B, Shanker AK, 2012. Dryland agriculture: bringing resilience to crop production under changing climate. In: Crop stress and its management: Prospectives and strategies. Springer Netherlands. pp. 19-44.
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Contributors A. Thirugnanavel, Scientist (Horticulture), ICAR Research Complex for NEH Region, Nagaland Centre, Jharnapani, Medziphema, Nagaland – 797106, e-mail:
[email protected] Bidyut C. Deka, Principle Scientist and Joint Director, ICAR Research Complex for NEH Region, Nagaland Centre, Jharnapani, Medziphema, Nagaland – 797106, e-mail:
[email protected] Ch. Roben Singh, Subject Matter Specialist (Agronomy), ICAR Research Complex for NEH Region, Krishi Vigyan Kendra, Dimapur, Jharnapani, Medziphema, Nagaland – 797106, e-mail:
[email protected] Christy B.K. Sangma, Scientist (Soil Science), ICAR Research Complex for NEH Region, Nagaland Centre, Jharnapani, Medziphema, Nagaland – 797106, e-mail:
[email protected] D.J. Rajkhowa, Principal Scientist (Agronomy), Division of Natural Resource Management, ICAR Research Complex for NEH Region, Umiam-793 103, Meghalaya, e-mail:
[email protected] D.M. Firake, Scientist (Entomology), Division of Entomology, ICAR Research Complex for NEH Region, Umiam-793 103, Meghalaya, e-mail:
[email protected] Dibyendu Chatterjee, Scientist (Soil Science), ICAR Research Complex for NEH Region, Nagaland Centre, Jharnapani, Medziphema, Nagaland – 797106, e-mail:
[email protected] G.T. Behere, Senior Scientist (Entomology), Division of Entomology, ICAR Research Complex for NEH Region, Umiam-793 103, Meghalaya, e-mail:
[email protected] Imtisenla Walling, Technical Officer (Gramin Krishi Mausam Sewa), ICAR Research Complex for NEH Region, Nagaland Centre, Jharnapani, Medziphema, Nagaland – 797106, e-mail:
[email protected] Jurisandhya Barik Bordoloi, Assistant Professor (Soil Science), Department of Agricultural Chemistry and Soil Science, School of Agricultural Sciences and Rural Development (SASRD), Nagaland University, Medziphema-797106, Nagaland, email:
[email protected] Kolom Rabi, Subject Matter Specialist (Plant Breeding), ICAR Research Complex for NEH Region, Krishi Vigyan Kendra, Dimapur, Jharnapani, Medziphema, Nagaland – 797106, e-mail:
[email protected] Lahar Jyoti Bordoloi, Farm Manager (Tech. Officer, T-7-8), ICAR Research Complex for NEH Region, Nagaland Centre, Jharnapani, Medziphema, Nagaland – 797106, e-mail:
[email protected] Manas Kumar Patra, Scientist (Animal Reproduction), ICAR Research Complex for NEH Region, Nagaland Centre, Jharnapani, Medziphema, Nagaland – 797106, e-mail:
[email protected] N.S. Azad Thakur, Principal Scientist and Head (Division of Crop Improvement and NRM), ICAR Research Complex for NEH Region, Umiam-793 103, Meghalaya, e-mail:
[email protected] P. Chowdhury, Subject Matter Specialist (Soil Science), Krishi Vigyan Kendra, Longleng, ICAR 104
Research Complex for NEH Region, e-mail:
[email protected] Rajesha G., Scientist (Plant Pathology), ICAR Research Complex for NEH Region, Nagaland Centre, Jharnapani, Medziphema, Nagaland – 797106, e-mail:
[email protected] S. Hazarika, Principal Scientist (Soil Science), Division of Natural Resource Management (Soil), ICAR Research Complex for NEH Region, Umiam-793 103, Meghalaya, e-mail:
[email protected] S.K. Das, Principal Scientist (Aquaculture), Division of Fisheries, ICAR Research Complex for NEH Region, Umiam-793 103, Meghalaya, e-mail:
[email protected] Sanjay Kumar Ray, Subject Matter Specialist (Soil Science), ICAR Research Complex for NEH Region, Krishi Vigyan Kendra, Wokha, Nagaland - 797111, e-mail:
[email protected] Saurav Saha, Scientist (Agricultural Physics), ICAR Research Complex for NEH Region, Mizoram Centre, Kolasib, Mizoram – 796 081, e-mail:
[email protected] Tasvina R. Borah, Scientist (Plant Pathology), ICAR Research Complex for NEH Region, Nagaland Centre, Jharnapani, Medziphema, Nagaland – 797106, e-mail:
[email protected] Yhuntilo Kent, Research Associate (Mega Seed Project on Pig), ICAR Research Complex for NEH Region, Nagaland Centre, Jharnapani, Medziphema, Nagaland – 797106, e-mail:
[email protected] Z. James Kikon, Subject Matter Specialist (Soil Science), ICAR Research Complex for NEH Region, Krishi Vigyan Kendra, Dimapur, Jharnapani, Medziphema, Nagaland – 797106, e-mail:
[email protected]
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