| Maize using single fertilization is wide increasingly in Heilongjiang Province and excessive nitrogen fertilizer causes N use efficiency too low and environmental pollution is getting worse. It is the method to solve the above problems by using controlled release nitrogen and various nitrogen application time. The method that improves the level of agricultural production and protecting the ecological environment has important significance. Without the premise of reducing rice yield, how to use different nitrogen fertilization and nitrogen application time to decrease nitrogen loss and reduce agricultural source pollution on environment.Experiments were conducted on different forms of nitrogen fertilizer on spring maize seedling growing, maize yield and output inscape, the nitrogen utilization efficiency, soil nitrate content of different layers, nitrogen balance impact tests in A Cheng research and teaching work center of North-east Agricultural University.The research results through the experiment indicated:(1)Nitrogen fertilizer significantly increased maize yield, kernel weight, tassel length, kernels per ear and maize nitrogen accumulation. The order of nutrient accumulations is K>N>P on maize; The distribution of N in maize was mainly in kernel and leaf, accounting for51.77%～55.32%and34.42%～36.49%of N in crop,respectively. P content was the highest in kernel, accounting for57.08%～64.75%of P in crop, and K content was the highest in leaf, accounting for37.15%～54.16%of K in crop. On the same condition of P and K, the same amount of different forms of nitrogen fertilizer applying could significantly promote the absorption of nutrients aboveground in the crop and increase maize yield, N, P, K and yield were increased up to43.94%,33.35%,69.05%and16.77%, and soil ammonium nitrogen was higher than nitrate in mature; the release of the50%ratio of controlled-release bulk blend fertilizers significantly improved NPK accumulation of maize plant and different organs and yield,and N use efficiency was58.57%.(2) In the whole growth period of maize,0-30cm soil nitrate nitrogen:Maize seedlings stage> Maize tasselling stage> Maize grain filling stage> Maize harvest stage. With the increase of time, the nitrate nitrogen content were decreased in the soil layers of different nitrogen fertilizer, soil nitrate nitrogen has gradually trend downward.0-90cm soil nitrate nitrogen accumulation continued to decline in the whole growth period, and was always higher than that of the treatment without nitrogen application. The estimation of yield of soil nitrate nitrogen was significantly higher than that of the actual output, there is a positive relationship between actual yield and yield estimation, the Poisson’s coefficient of0.836. (3) In harvest period, the content of soil ammonium nitrogen of different N treatments were higher than that of nitrate nitrogen in soil. Soil ammonium nitrogen and nitrate nitrogen of Sulfur coated urea applied in single fertilization were higher than other treatments, and the soil inorganic nitrogen residues highest significantly, apparent N loss minimum; The soil inorganic nitrogen residues has difference significantly between different nitrogen treatments. With the controlled release ratio of sulfur coated urea increasing, apparent N loss decreases, inorganic nitrogen residues increased. Nitrogen apparent loss of urea was significantly higher than controlled release nitrogen; Compared with split fertilization, Urea single fertilization can make the apparent N loss increased, soil inorganic nitrogen residues reduced. In maize harvest period,the nitrogen surplus was higher than the treatment without nitrogen application. It has significant difference between sulfur coated urea fertilizer in single fertilization and treatment without nitrogen application. The surplus of nitrogen is very easy to cause the leaching loss into the groundwater in the rain season. |
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