汾河灌区不同水氮管理措施下春玉米产量与水分生产力模拟与评价OA

To address the issue of low water and nitrogen use efficiency in spring maize production in the Fenhe Irrigation District of Shanxi Province,this study calibrated and validated the parameters of the SWAP-WOFOST-N model based on field experiments.On this basis,it simulated and analyzed the effects of different water-nitrogen treatments on spring maize yield,water productivity(WP),and partial factor productivity of nitrogen(PFPN),and further proposed relatively optimal water-nitrogen management measures under different hydrological year types.The results showed that the model exhibited high simulation accuracy for soil water content,soil temperature,leaf area index,yield,and nitrogen use efficiency.Specifically,the normalized root mean square error(NRMSE)of soil water content,soil temperature,and leaf area index was below 20％in both the calibration and validation phases,while the relative error(RE)of spring maize yield and nitrogen use efficiency was controlled within 5％.The simulation accuracy for soil salt content and nitrate nitrogen content was slightly lower,but their NRMSE still remained stable within 30％.With the goals of increasing(or stabilizing)yield and improving water and nitrogen use efficiency,the recommended irrigation quota and nitrogen application rate for wet years are 75 mm and 240 kg/hm²,respectively,which can increase the yield,WP,and PFPN by 4.8％,6.9％,and 8.3％compared with the current status.For normal precipitation years,maintaining the current irrigation quota of 150 mm while reducing the nitrogen application rate to 180 kg/hm² can significantly increase PFPN by 31.4％.For dry years,the recommended irrigation quota and nitrogen application rate are 225 mm and 180 kg/hm²,respectively,which can increase the yield by 9.4％.Compared with traditional water and fertilizer management,water-nitrogen management strategies based on different hydrological year patterns can reduce irrigation water by 50％in wet years and nitrogen application by 25％in normal and dry years,thereby improving crop yield as well as water and nitrogen use efficiency.