The Rational Fertilization On High-yield Paddy Field In Middle And Lower Reaches Of Yangtze River

Field investigation and soil sample analysis methods were adopted on a long-term experiment in Qiyang Hunan province China. The objective was to probe the effects of chemical and organic fertilizers on rice yield, soil organic matter and soil nutrients. According to the investigation on 19 high-yield paddy field with yield and fertilization and different cropping system and farmland management in Hunan, Jiangxi, Zhejiang, Anhui and Hubei Province, the relationship between fertilization and yield were studied and The best fertilization mode was established.The main results were as follows:(1) The combinative use of chemical and organic fertilizers was an optimum way for high yield and rise of soil fertility.(2) Application of both chemical and organic fertilizers significantly increased soil organic matter, and application of organic fertilizers increased soil organic matter by 48 % compared to the chemical fertilizer.(3) Organic fertilizers made greater contribution to rise of soil total nitrogen and hydrolysable nitrogen than chemical fertilizer N, but less contribution to soil total P and available P than that of chemical fertilizer phosphorus. The organic fertilizer increased soil total N by 30 % and hydrolysable N by 16 % while the chemical P fertilizer increased 30 % more total P and 115 % more available P than did the organic fertilizer.(4) The yield in double rice system and rape-rice rotation field were about 16893 and 13000 kg/hm2. The optimum amount of N, P2O5 and K2O fertilization in double rice system were about 461, 130 and 430 kg/hm2, and the ratio of N: P2O5: K2O was about 1:0.28:0.85. The optimum amount of N, P2O5 and K2O fertilization in rape-rice rotation field were about 200, 145 and 250 kg/hm2, and the ratio of N: P2O5: K2O was about 1:0.72:1.23.