应用根系层水质模型分析冬小麦-夏玉米轮作体系的农田水氮利用效率Ⅱ:模型的验证与情景分析

Applying Application of Root Zone Water Quality Model to simulate water and nitrogen use efficiency of winter wheat-summer maize double cropping system Ⅱ.Model validation and scenario analysis

在就禹城试验站对根系层水质模型(RZWQM)的参数进行灵敏度分析和标定的基础上,模拟了1960—2005年该试验站冬小麦-夏玉米轮作条件下的冬小麦和夏玉米产量、水分利用效率及氮肥偏生产力,并将模拟的冬小麦和夏玉米产量与禹城市农业统计年鉴显示的1985—2005年的产量进行了对比。结果表明:经过标定后的RZ WQM能够较好地模拟夏玉米产量(平均相对误差为-13.3%),可以模拟冬小麦产量在年际间的变化趋势(平均相对误差-54.2%)。针对所设计的9种节水省氮的灌溉与施氮方案开展了多组情景模拟分析,结果显示较好的情景是:冬小麦在播前、拔节和开花期各灌溉75mm的水;夏玉米当平水年和丰水年时在播前灌溉一次56mm的水,当枯水年时在播前和抽穗期各灌溉84mm的水,当特枯水年时在播前和抽穗期各灌溉111mm的水。冬小麦在播前和拔节期分别施氮77.7kg/hm2和155.3kg/hm2,整个生育期施氮量为233kg/hm2;夏玉米在苗期(播后5d)和大喇叭口期各施氮70.7kg/m2和141.3kg/hm2,整个生育期施氮量为212kg/hm2。这样优化的灌溉与施氮方案能够取得较好的增产效果和较高的水氮利用效率,即:冬小麦-夏玉米轮作体系的粮食产量为10 302kg/hm2、水分利用效率为1.40kg/m3、氮肥偏生产力为23.2kg/kg。

Based on the sensitivity analysis and calibration of the Root Zone Water Quality Model（RZWQM） at the Yucheng Experimental Station,the simulated crop yield,water and nitrogen dynamics in winter wheat（Triticum aestivum L.） and summer maize（Zea mays L.） double cropping systems from 1960 to 2005 are compared with the data obtained from the statistical yearbooks of Yucheng county and the Weishan irrigation district.It is found that the mean relative error（MRE） for the simulated yields of winter wheat and summer maize from 1985—2005 were-54.2% and 13.3%,respectively.Then the results of scenario analysis show that the best choice for the purpose of achieving the highest yields and WUE might be the combination between the optimal irrigation schedule and the optimal fertilizer management.The yield,WUE and partial factor productivity（PFP） of the crop in this scenario were 10 302kg/hm2,1.40kg/m3 and 23.2kg/kg,respectively.