不同施氮量对玉米-大豆套作区域水氮利用效率的影响OA

Maize soybean intercropping has typical resource competition and complementarity.Maize grows quickly in the early stage and has a strong demand for nitrogen,which may suppress soybeans.However,soybeans can fix nitrogen in the later stage and compensate for system nitrogen.Therefore,in the maize soybean intercropping area,different nitro-gen application rates directly affect system yield,land use efficiency(LER),and water and nitrogen use efficiency.This study set up four treatments:no nitrogen(CK),low nitrogen(N1·150 kg/hm2),medium nitrogen(N2·300 kg/hm2),and high nitrogen(N3·450 kg/hm2),to determine the effects of different nitrogen fertilizer levels on the system yield,land equivalent ratio,and water and nitrogen use efficiency of maize soybean intercropping.The results showed that under N2 treatment,the average yield was significantly increased by 63.7％compared to CK,and the high-est maize grain yield could be achieved when the nitrogen application rate was 250～300 kg/hm2.Compared with CK and N1,N2 treatment is the most effective in improving the water use efficiency of maize;The agronomic efficiency of nitrogen fertilizer was higher under N1 and N2 treatments.The research results can contribute to the efficient utilization of water and nitrogen in maize soybean intercropping areas and promote green yield increase provide theoretical basis and feasible approaches.