Abstract: In order to improve the economic efficiency of nitrogen and reduce agricultural pollution,a field experiment was conducted to investigate the effects of different fertilizations on soil nitrate N distribution and accumulation,yields and fertilizer-nitrogen use efficiency under winter wheat summer maize cropping system in the Ziya River Basin.The results showed that the distribution and accumulation of the soil inorganic nitrogen was mainly nitrate N after wheat-maize rotation cycle.The soil nitrate content increased With the increasing nitrogen fertilization.The nitrate N in 0-40 cm depth of soil of conventional fertilization was significantly higher than the optimal fertilization and control treatments at corn harvesting.Compared with conventional fertilization,the residual nitrate N in 0-1.2 m depth of optimized fertilization,optimized fertilizer+organic fertilizer,optimized fertilization+straw,slow controlled fertilizer+organic fertilizer decreased 43.55%,26.53%,40.82% and 42.89%,28.96%,38.28%,32.52% respectively.The yields of winter wheat summer maize increased slightly.The optimized fertilizations significantly increased fertilizer-nitrogen use efficiency of winter wheat and summer corn,which increases 18.94%-51.20% in winter wheat season,and 13.77%-43.68% in summer corn season.Compared with conventional fertilization,optimized fertilization and controlled-release nitrogen fertilizer measures improved economic and environmental benefits significantly.The nitrogen fertilization measures were recommended.

Key words: Fertilizations, Winter wheat, Summer maize, Inorganic nitrogen, Nitrate N

CLC Number: 

• S143.1