The Effects Of Different Types Of Nitrogen Fertilizers And Irragation Treatments On Field Ammonia Volatilization And Nitrification-Denitrification

In the filed ecosystem, the loss of nitrogen in its cyclic process causes not only decrease of itself for the recycle process, but also recede of the productivity level and negative effects on environment. The excessive usage of fertilizers contributes to low usage rate and server loss, which is the significant path of the farmland nonpoint source pollution. The researched of the methods to control the pollution, boosting the usage rate of fertilizers and productivity, in the meantime providing evidence for the technical of controlling fertilizer pollution is important.The article studied mainly that: (1) the effects of different types of fertilizers on the ammonia volitalization of wheat field, (2) the effects of different irrigations on the ammonia volatilization of wheat field, (3) the effects of different types of fertilizers on nitrification-denitrification of the wheat field, and (4) the effects of different types of fertilizers with irrigations on the yield of wheat. The main conclusions showed as:1.During the period of first month after the sowing and fertilizers treatment, the volatilization rates of different types of fertilizers differ significantly. The soil moisture is about 20% with low level irrigation treatment, with which the volatilization percentage of treatments of urea basal application, the half amount of urea basal application, slow-released fertilizer, and compound fertilizer are respectively 0.84%, 1.08%, 0.44%, and 1.07%, but 0.77%, 0.73%, 0.70%, and 1.36% for high level irrigation treatment, whose soil moisture is above 25%. The sequence of percentage of volatilization loss is compound fertilizer>urea>low-released fertilizer for the equal amount nitrogen.2. The nitrification rate and denitrification rate of the field for slow-released fertilizer treatment is the lowest and significantly different with the other three fertilizer treatments. The nitrification rate decreased by 32.6%, 42.0% and 40.5%than urea basal application, the half-basal-half-top-dressing of urea respectively; with 21.0%, 26.5% and 28.5% lower than them for denitrification rate respectively.3. The treatment of irrigation has effects on the yield of wheat, in which the high level irrigation caused the increment of granule amount by 4.41%, 1.09%, 2.14% and 1.73% than low level irrigation for urea basal application, the half-basal-half-top-dressing of urea, slow-released fertilizer, and compound fertilizer respectively, and 2.32%, 0.75%, 1.14% and 2.55% for thousand granular weight.4. different fertilizers treatments have great influence on the yield of wheat, among which the slow-released fertilizer is most distinctive, and followed by compound fertilizer and the half-basal-half-top-dressing of urea, the least effect is for urea basal application. The sequence of fertilizer utility rate is slow-released fertilizer> compound fertilizer> half-basal-half-top-dressing of urea> urea basal application. The utilization rate of fertilizer are 43.3%,37.3%,25.6% and 20.5% respectively.