Characteristics of N loss and its environmental effects in the dryland of Huang-Huai-Hai plain
黄淮海平原旱田氮素损失特征及其环境影响研究

Based on the N balance parameters and statistical data,the characteristics of N loss and its environmental effects for the dominant crops of winter wheat and summer maize in Huang-Huai-Hai plain were studied.The results indicated that with the increase of N fertilizer application from 1992 to 1998,the total N loss,ammonia volatilization loss,nitrificattion-denitrification loss,leaching and runoff per unit area were gradually increased.The residual rate,loss rate and utilization efficiency were different for N fertilizers and crops;the loss of N fertilizers was much higher in the field of summer maize than that in the field of winter wheat.At last,the environmental effect of N loss and possible countermeasures were discussed.