Effect of Long term Located Fertilization on Land Productivity

Based on the trial of continuous 15 year location in the soil fertility and land productivity, the results showed that the application of different organic manure and chemical fertilizers,the organic matter content in soil increased by 24～149 g/kg and the available N、P and K contents in soil had increased by 15～35 mg/kg,8～15 mg/kg and 69～163 mg/kg respectively comparing with the corresponding treatments of chemical fertilizer. The average yield increase from N fertilizer was 35.2%, with a contribution ratio of 68.2% to the land productivity. The interaction value of combination of N and organic manure was 30.1% with contribution ratios of 92.4% and 81.9% to the land productivity and yield increase.The average yield increase from P fertilizer was 64.5%,with a negative interaction value to organic manure. The average yield increase from K fertilizer was 11.3%,and the combination of K fertilizer and organ manure showed negative interaction .The contributions to the land productivity of organic manure and the blank treatment were 69.9% and 53.3% respectively so the assorted application of organic manure and chemical fertilizers NP is the best way to increase the yield and soil productivity