基于APSIM模型模拟水氮调控对旱地春小麦产量的影响

Effect of precipitation and nitrogen application on spring wheat yield in dryland based on APSIM model

为明确水氮调控对春小麦(Triticum aestivum)产量的影响,研究自然降水条件下小麦产量达到最佳所需含氮量,将田间试验数据与农业生产系统模拟模型(Agricultural Production System Simulator,APSIM)结合,分别设定降水和施氮梯度为春小麦的产量变化的影响因素,并对模型予以检验。APSIM模型对春小麦产量模拟精度较高,决定系数(R2)、归一化均方根误差(NRMSE)、模型一致性指标(D)分别为0.95、27.36%和0.91。随降水量或施氮量的增加,整体产量表现出先增后减趋势;其次,在所有组合中降水增加到20%,施氮量为157.5 kg·hm^–2的处理较好,平均产量最高达到5 406.64 kg·hm^–2;最后,根据产量变化曲面拟合方程得出产量最佳方案:当自然降水增加55%,施氮量增加到257.25 kg·ha^–1,产量达到最佳,为5 988 kg·hm^–2。

The aim of the present study was to investigate the effects of water and nitrogen on the yield of spring wheat in the middle Loess Plateau of Gansu Province, China. Using experimental field data and the Agricultural Production System Simulator (APSIM), precipitation and nitrogen application gradients were established. The results demonstrated that the APSIM model was highly accurate for simulating spring wheat yield;the determinant coefficient, normalized root mean square error, and model consistency index were 0.95, 27.36%, and 0.91, respectively. Furthermore, the yield of spring wheat first increased and then decreased with increases in precipitation or nitrogen application. The maximum mean yield (5 406.64 kg·ha^-1) was observed at 20% precipitation and a nitrogen application rate of 157.5 kg·ha^-1. However, according to the curve fitting equation for yield variation, yield would be maximized (5 988 kg·ha^–1) at 55% precipitation and a nitrogen application rate of 257.25 kg·ha^-1.