S12 Assessing the role of soil functions for achieving SDGs
Improving Soil Functions for Sustainable Agriculture- a case study from South India A Nexus of Soils-Environment-Livelihoods
E.V.S.Prakasa Rao Independent(Formerly, Chief Scientist, CSIR-Centre for Mathematical Modelling and Computer Simulation, Bengaluru and Head, Central Institute of Medicinal and Aromatic Plants, Research Centre, Bengaluru, India)
[email protected]
Soil- Environment- EconomicsEquity Nexus
Equity
Soil
Economics
Soil
Environment
Physiographic Regions in south India
Soil groups in south India
LCC in Southern States
Soil constraints In South India
Andhra Pradesh Black soils: pH 8.5 – 9.0, poor in organic matter and nitrogen but sufficient in P and K. Red soils: pH 6.8 – 8.0, light, dry and rain fed crops with poor yields. , poor in organic matter, N and available P, moderate in K. Coastal alluvial soils: Sandy, Poor in plant nutrients. and organic matter. River alluvial soils: Rich in plant nutrients. Karnataka Laterite soils: pH 4.5 – 6.0, low in bases, poor in plant nutrients in organic matter and N. Kerala
Peaty soils (black): pH as low as 3.9, 10 to 40 % organic matter, 0.4% K2O, poor in P2O5 Tamil Nadu Deltaic alluvial soils: pH 7.0 – 8.2, low in bases, poor in organic matter and N and P but rich in K. Forest and hill soils: pH 4.5 – 6.5, 0.1 – 0.7% N, poor in bases.
WHY A NEXUS AMONG SOILS – LIVELIHOODS-ENVIRONMENT? “ Economic survival and viability are the primary goals of land managers, and while most appreciate the need for environmental conservation, the simple fact remains that ‘it is hard to be green when you are in the red’ ”. (JW Doran & MR Zeiss, 2000. Appl. Soil. Ecol. 15, 3-11)
Nexus of farmers’ needs and soil environment
Farmer’s needs
Soil environmental conservation
Yields Profits Stability Benefit cost ratio (energy and costs)
Soil organic matter Top soil depth Soil fertility Soil reaction Physical properties of soil
Estimates of soil degradation in India Process
GLASOD (Mha)
Others (Mha)
Water erosion
32.8
74-77
Wind erosion
10.8
13-39
Soil fertility decline
29.4
26
Waterlogging
3.1
7-9
Salinization
4.1
7-26
Lowering of water table 0.2
NA
GLASOD – Global Assessment of Soil Degradation (R.Lal, Soil carbon sequestration in India. Climatic Change, 65, 277-296, 2004)
Demography of sample villages
Literacy
13.4%
Average land holding
1-3 ac
Economic status
Poor
Delicate soil ecosystems supporting livelihoods
Crops and economics in western ghats region in India
Vetiver; arecanut and a distillation unit in the background Vetiver with banana Crop
Rice cultivation in valleys
Net income (Rs/ha)
Rice
12 000
Arecanut
49 000
Cashew nut
53 000
Vetiver
123 000
E.V.S.Prakasa Rao et al., 2015.Sust. Agric. Rev. (in press)
Carbon should be sequestered to maintain soil functions and also to protect environment
Such systems planted in 10% of wastelands can fix up to 200 Tg C yr -1 in India (M.Singh, N.Guleria, E. V. S. Prakasa Rao and P.Goswami(2014)Agronomy for Sustainable Development 34(3), 603-607 DOI 10.1007/s13593013-0184-3.)
Recycling of agro-wastes by vermi-composting ( 20 ftX 6 ft X 1.5 ft pits) Vermi-compost produced
300 kg/pit/batch
N(%)
1.4
P(%)
0.12
K(%)
0.22
Organic C (%)
22.9
E.V.S.Prakasa Rao et al., 2015.Sust. Agric. Rev. (in press)
Effect of organic and conventional methods of cultivation of medicinal and aromatic plants on some soil properties (4 yrs)
Treatment Organic Bulk Microbial Available carbon density biomass P2O5 (%) (g/cm3) (mg/kg) (kg/ha)
Organic
0.63
1.43
90.0
22.95
Inorganic
0.39
1.62
27.4
19.1
(Puttanna,K., E. V. S, Prakasa Rao, C. T. Gopinath, T. N. Parameswaran, Alok Kalra, S. Ramesh and R. P. Singh, International Seminar India Organic 2007, New Delhi, 29 Nov. 2007- 2 Dec. 2007 )
Soil analysis in an Eucalyptus citriodora plantation (at the end of 10 yrs) Soil characteristic
Fallow soil
E. citriodora plantation
pH 0-15 cm 15-30 cm
5.64 5.70
5.79 5.81
Organic carbon 0-15 cm 15-30 cm
0.35 0.35
0.46 0.45
Available N (kg/ha) 0-15 cm 15-30 cm
310 310
318 278
Available P (kg/ha) 0-15 cm 15-30 cm
6.6 10.3
3.4 7.7
Exchange K (kg/ha) 0-15 cm 15-30 cm
524 408
488 423
CEC (meq/100g) 0-15 cm
2.0
2.6
Prakasa Rao, E,V,S, et al., Fafai J., 1(3), 4447, 1999
Nirogen being very mobile in tropical soils, requires proper management to improve N-use efficiency
Techniques Split application Urea supergranules Neem cake coated urea DCD-treated urea Fe-deficiency correction Combination of organics and inorganics
% improvement over conventional method 16 12-15 25 31 36 33
E.V.S.Prakasa Rao. Indian Journal of Agronomy 56 (4): 280-296 (2011)
Protection of soil – perennial aromatic grasses provide a way Cashew nut and citronella grass
Cashew nut
Ammonia volatilization losses from urea and NCU applied to soil
Prakasa Rao, E.V.S. (1996).In Neem and Environment Vol. 2 eds. R.P.Singh et. al, Oxford & IBH Publ. Co., Ltd., pp 815-819.
Effect of spentgrass : urea-N ratio on release of NO3- - N
(Puttanna, K., & Prakasa Rao E.V.S.- , Sehgal J. Ed. et al. Red and Lateritic Soils of India – Resource Appraisal and Management, NBSS Publ. 37 NBSS&LUP, Nagpur, India, 346 p., 1993)
In situ soil moisture conservation in rainfed palmarosa Method
Herb yield (t/ha/6 harvests)
Weed biomass (t/ha)
Mulching
16.1
22.5
Wider interrow-narrow intrarow spacing
18.5
13.2
Ridges & Furrows
21.5
10.9
Life saving irrigation
21.2
12.1
Normal planting
21.0
12.6
Incorporation of spent material
25.3
10.0
L.S.D. (P=0.05)
2.98
-
E.V.S.Prakasa Rao et al., 2001. European J. Agronomy, 14: 167-172.
P deficiency can be rectified to increase income and soil P status in rain-fed palmarosa P application (kg/ha/yr)
Net balance of available P(kg/ha) in soil(0-15 cm)
Palma-rosa oil yield
0
-0.9
38.1
17.5
7.0
40.4
3000
35.0
19.6
44.3
6000
52.5
19.7
47.0
13500
(kg/ha)
Extra income (Rs/ha)
E.V.S.Prakasa Rao et al., 2001. European J. Agronomy, 14: 167-172.
Technology helps economics and environment in vetiver oil distillation Method of distillation
Traditional distillation unit
Method of distillation
Firewood consumption (kg/batch)
Man days/batch
Conventional
600
18
Improved
150
3
Vetiver oil recovery (%)
Vetiver oil yield (kg/ha)
Conventional
0.78
17
Improved
1.20
25
Improved distillation E.V.S.Prakasa Rao et al., 2015.Sust. Agric. Rev. (inunit press)
Vetiver dry leaves are used to make temporary hutments for the farm workers in the western ghats area, India
Cultivation of vetiver on hill slopes in western ghats, India provides livelihood support besides protecting the soil from erosion
Alternate uses of farm products can generate employment and provide livelihoods
Vetiver by- products
Run off and soil losses need to be controlled in slopes of high rainfall regions
Method
Run off (% of rainfall)
Soil loss (t/ha)
Infiltrati on (% of rainfall)
Control
23.3
14.4
76.7
3.9
84.5
Vetiver 15.5 on contours
Truong(1993)
Man –Soil Nexus
Soil provides food, fibre, and also shelter
Key Message,Finding and Future Agenda • Message: The nexus among farm income- soil functions- environment is key to livelihoods in south India • Finding: Proper crop diversification, soil management and technology have contributed to the livelihoods • Future agenda: Small farmers have to be made partners not only in agriculture but also in soil health and environmental protection through appropriate institutional mechanisms
Thank you for your attention
