Main Crop Fertilizer Use Efficiency On Typical Watershed Of Purple Soil In Rainy Zone Of West China

In order to improve the soil nutrient levels and crop yield, we widely use chemical fertilizers in agricultural production. However, the continued increase of the amount of chemical fertilizer achievements in food production, at the same time, it also brings a series of environmental problems. Due to the low utilization rate of fertilizer, fertilizer huge amount of loss of active ingredients, the consequent decline in soil fertility, reduced crop quality, environmental pollution and other serious consequences. In the conditions of limited arable land resources, how to increase food production, scientific, rational, and effective application of fertilizer to avoid unnecessary waste and environmental pollution caused by fertilizer abuse sustainable development to create a conservation-oriented society and agriculture in China has an important significance.In this paper, through the field fertilization experiment on three kinds of local crop in rainy zone of West China Center of the Nanjiao Village of Ya’an City, Zancun in small watershed, explore different fertilizer application rate conditions, the yield of corn, rice and rape affect crop nitrogen, phosphorus, potassium content and the impact of the cumulative amount of nitrogen, phosphorus, potassium use efficiency. Discuss the three crops theoretical optimum fertilization and optimum yield in this area, fertilizer use efficiency variation reveals the absorption and utilization of nitrogen fertilizer phosphorus, potassium. The main findings are as follows:(1) Nitrogen fertilizer significantly increased corn, rice and rape of three kinds of crop yield, different nitrogen fertilizer have effect on crop yield. Grain yield and nitrogen application amount of related crop were parabola between the theoretical optimum amount of nitrogen fertilizer, maize, rice and rape of three kinds of crops were289.2kg/hm2,206.6kg/hm2and260.0kg/hm2, the highest yield theory were6280.2kg/hm2,7451.6kg/hm2and2755.7kg/hm2.(2) Nitrogen fertilization influences on corn, rice and rape root-seeds ratio, grass-seed ratio and root-shoot ratio caused by. With the increase of nitrogen fertilizer application, three kinds of crop root-seeds ratio, grass-seed ratio and root-shoot ratio has decreased, effects on the rape is the most obvious, followed by corn and rice. (3) The use of nitrogen fertilizer not only can increase the nitrogen content and nitrogen of corn, rice and rapeseed crop in three parts of the accumulation, but also will increase three crops of phosphorus and potassium accumulation amount. With the increasing of nitrogen fertilizer, nitrogen accumulation amount of three kinds of crops were increased from49.6kg/hm2,53.3kg/hm2and25.2kg/hm2to127.3kg/hm2,93.5kg/hm2and126.9kg/hm2; The phosphorus accumulation amount were increased from3.6kg/hm2,6.6kg/hm2and5.1kg/hm2to8.0kg/hm2,10.7kg/hm2and20.2kg/hm2; The potassium accumulation amount were increased from86.2kg/hm2,88.3kg/hm2and49.8kg/hm2to170.2kg/hm2,139.8kg/hm2and145.4kg/hm2.(4) With the increasing of nitrogen fertilizer, nitrogen fertilizer use efficiency decreased, and the utilization efficiency of phosphorus, potassium fertilizer could increase. Three kinds of crop nitrogen use efficiency were decreased respectively from34.7%,19.1%and45.3%decreased to25.9%,13.4%and33.9%;But the utilization efficiency of three crops of phosphorus and potassium was improved, the utilization efficiency of P fertilizer were increased respectively from9.5%,11.9%and32.3%to16.9%,15.8%and57.7%; the utilization efficiency of K fertilizer were increased respectively from41.6%,25.2%and46.9%to67.6%,42%and76.8%.Fertilizer use must follow the scientific laws, otherwise it will cause a series of serious consequences. Improve fertilizer use efficiency measures are applied, fertilizer to use and formula fertilization, the main idea is to suit one’s measures to local conditions of fertilization.In Rainy zone of West China, for a long time, the application of fertilizer with blindness, and lack of scientific basis. In this paper the main crop for fertilizer in the region reference volume, has certain guiding significance for the local agricultural production and using fertilizer and protecting the ecological environment.