基于不同底墒的最优水肥调控方案研究

为了探讨不同底墒条件下的水肥运筹，在大型半自动控制防雨池栽条件下，通过设置不同底墒、生育期补水量及施氮量，研究了各试验因子主效应及互作效应。结果表明，各试验因子对冬小麦产量的影响顺序由大到小依次为底墒、施氮量、补水量，对水分利用效率的影响顺序由大到小依次为底墒、补水量、施氮量；底墒、施氮量、补水量与冬小麦产量、水分利用效率的耦合分别存在显著的负效应和正效应；在底墒充足条件下，施氮量能充分发挥底墒的增产作用，提高水分利用效率。通过优化分析，得出各指标可接受区域（大于等于0.95最大值）的重叠区域所对应的水氮范围分别为：90~100mm和104.5~224.5kg/hm2（底墒450mm），94.3~100mm和105.8~186.4kg/hm2（底墒350mm）。底墒为650mm时，冬小麦产量最大，水分利用效率较高，所对应的水氮范围分别为71~100mm和141.2~264.8kg/hm2。

Water and Nitrogen Inputs Optimization Based on Different Soil Water Storage at Planting

In order to explore the nitrogen rate and water management, the multivariate regression analysis was applied to explore how levels of available soil water storage at planting (WB), supplemental water during the growing period (R) and nitrogen rate (N) affected yields of winter wheat (Triticum aestivum L.) and water use efficiency (WUE) in a mobile rain-proof shed between 2013 and 2015. The results showed that effects of all factors on yields of winter wheat followed the sequence of WB, N and R. Likewise, effects of all factors on WUE followed the sequence of WB, R and N. The coupling of all factors on yield and WUE had significant negative and positive effects, respectively; in adequate WB, nitrogen rate could fully exploit the role of WB on yield increasing, and improve WUE. Acceptable yield and WUE were defined as greater than or equal to 0.95 of the maximum predicted response within the range of the treatments. Overlap of acceptable zones of grain yields and WUE were respectively 90~100mm and 104.5~224.5kg/hm2 (WB=450mm),94.3~100mm and 105.8~186.4kg/hm2 (WB=350mm). At WB=650mm, overlap of acceptable zone of the maximum grain yield and the high WUE was 71~100mm and 141.2~264.8kg/hm2.