Effects of Different Fertilizer’s Application Systems on Soil Fertility and Rice Yield

Based on 18-years long-term fertilizer experiments,characters of the N,P,K nutrient in paddy soil and rice yield were analyzed after application of different fertilizers. The results showed that:compared with the treatment without, organic manure,combined with chemical fertilizers,could increase the quantity of OM,CEC,available and total N,P, K,so it was the most remarkable of the several treatments.The nutrient content in treatment of farmers’ fertilization practice (FFP) and NPK maintained at an identical level.Treatment NP could increase the ratio of effective P,and at the same time available K reduced significantly.Both treatments of straw’s return to field and that of NK could significantly increase available K,by 48.4% and 32.3% respectively compared to the treatment NPK.Effects ratios of soil organic matter was similar in all the chemical fertilizer treatments.While applying organic manure was the most effective way to increase soil organic matter.The contents of soil organic matter was positively correlated with that of soil total nitrogen and CEC(r 1 = 0.959**;r 2 =0.914**).