Effects of Different Nitrogen Forms on Spring Maize Yield,N Use Efficiency and Soil Nitrate Nitrogen

Effects of nitrogen fertilizer types on the maize yield, variation of soil nitrate content in the 0-90 cmlayers with maize growing stages and nitrogen use efficiency(NUE) were carried out on a typical black soil in a fieldexperiment. The results showed that the 90 cm deep soil layer, soil residual nitrate was elevated by the applicationof nitrogen fertilizer by about 30%, but it decreased too with the growing stages of maize, and common urea re-mained 20% higher than that of control at harvest. Compared with common urea, soil nitrate content of controlled-re-lease nitrogen fertilizer decreased slowly in the early stage and fast in the lately stage, soil residual nitrate contentwas lower. Controlled-release compound fertilizer could meet the demand for maize growth earlier stage and laterstage of soil nitrate nitrogen, improve yield and maximize nitrogen fertilizer use efficiency to 55.41% and achievethe purpose of single fertilization. Yields and N use efficiency of sulfur coated urea fertilizer by single fertilizationwere the lowest. Compared with the other nitrogen treatments, there was a significant difference with those.