NP. NP. K. NP. KM h. NP. KM. P ercen tag. e o f so il Olsen. -P to total P. (%. ) d d cd c b a. D. 0. 4. 8. 12 .... Daniel Richter, Duke University,. USA for his constructive ... Naidu R, Kookana R S, Sumner M E, Harter R D, Tiller K G. 1997. Cadmium ...
Journal of Integrative Agriculture 2014, 13(3): 597-603
March 2014
RESEARCH ARTICLE
Soil Organic Carbon Accumulation Increases Percentage of Soil Olsen-P to Total P at Two 15-Year Mono-Cropping Systems in Northern China SHEN Pu1, HE Xin-hua1, 2, XU Ming-gang1, ZHANG Hui-min1, PENG Chang3, GAO Hong-jun3, LIU Hua4, XU Yong-mei4, QIN Song5 and XIAO Hou-jun5 1
Key Laboratory of Crop Nutrition and Fertilization, Ministry of Agriculture/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R.China 2 School of Plant Biology, University of Western Australia, Crawley, WA 6009, Australia 3 Institute of Agricultural Resources and Environment, Jilin Academy of Agricultural Sciences, Changchun 130001, P.R.China 4 Institute of Soil and Fertilizer, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, P.R.China 5 Guizhou Institue of Soil and Fertilizer, Guiyang 550006, P.R.China
Abstract Soil organic carbon (SOC) and soil Olsen-P are key soil fertility indexes but information on their relationships is limited particularly under long-term fertilization. We investigated the relationships between SOC and the percentage of soil Olsen-P to total P (PSOPTP) under six different 15-yr (1990-2004) long-term fertilizations at two cropping systems in northern China. These fertilization treatments were (1) unfertilized control (control); (2) chemical nitrogen (N); (3) N plus chemical P (NP); (4) NP plus chemical potassium (NPK); (5) NPK plus animal manure (NPKM) and (6) high NPKM (hNPKM). Compared with their initial values in 1989 at both sites, during the 11th to 15th fertilization years annual mean SOC contents were significantly increased by 39.4-47.0% and 58.9-93.9% at Gongzhuling, Jilin Province, and Urumqi, Xinjiang, China, under the two NPKM fertilizations, respectively, while no significant changes under the no-P or chemical P fertilization. During the 11th to 15th fertilization years, annual mean PSOPTP was respectively increased by 2.6-4.2 and 5.8-14.1 times over the initial values under the two chemical P fertilizations and the two NPKM fertilizations, but was unchanged in their initial levels under the two no-P fertilizations at both sites. Over the 15-yr long-term fertilization SOC significantly positively correlated with PSOPTP (r2=0.55-0.79, PN≈Control at Gongzhuling whereas as hNPKM>NPKM>NPK NP N≈Control at Urumqi (Fig. 2-C and D).
Relationships between soil organic carbon and percentage of soil Olsen-P to total P Soil organic carbon significantly positively correlated
with PSOPTP at the two sites (r2=0.55-0.79, P
