POTENTIAL AND YIELD-INCREASE EFFECT CAUSED BY ORGANIC MATTERS RECYCLING IN RED PADDY SYSTEM
ZHOU Wei-jun 1,2, WANG Kai-rong 2, ZHANG Guan-yuan 1 (1. Department of Resource,Environment and Agro-Chemistry, Huazhong Agricultural University, Wuhan 430070,China;2.Taoyuan Experimental Station of Agro-ecosystem Observation , Changsha Institute of
The results of field experiments within 10 years in red paddy systems indicated the potential of recycling organic matters was significantly great. The amount of N, P and K outputs by rice harvest were up to 224.7, 53.0 and 271.4 kg/hm 2, respectively. The amount of returning N, P and K nutrients were up to 115.1, 35.8 and 231.5 kg/hm 2 using the method of organic matters and were 51.2%, 67.5% and 85.3% of the output of the paddy system, respectively. Under recycling nutrients, the yields of rice increased were 3 056, 2 753, 1 543 kg/hm 2, and 984 kg/hm 2 based on fertilizing nothing, N, NP and NPK respectively. It could increase the ability of stabilized yield of the system and decrease the annual variation coefficient of grain yield under organic matters recycling in red paddy systems. Variation coefficient of the cycling treatments is smaller than that of no cycling treatment. There was a marked accumulative residual effect of recycling nutrients on crop yield, based on NPK fertilizers, the average increase rate of crop yields caused by recycled nutrients was 7.2% in the first five years, but raised up to 9.4% in late five years within the experimental period.