中文摘要：

水和化肥的最佳的使用能提高冬季小麦产量并且在 dryland 增加水和化肥用法的效率农业系统。以便为冬季小麦优化水和氮(N) 管理，我们在黄土高原上在中国科学院的 Changwu Agro 生态的试验性的车站从 2006 ～ 2008 进行了地实验，中国。小麦产量和土壤水分蒸发蒸腾损失总量(et ) 的回归模型在这研究被建立评估联合效果的水和化肥并且决定最佳的联合领域。结果证明显著地在庄稼产量，和最佳的灌溉和 N 输入罐头上有水和 N 化肥的积极效果增加冬季小麦的收益。在干旱年(20062007 ) 里，冬季小麦的最大的收益(Y 最大) 是为有 324 公里灌溉和 310 kg/hm2 N 的处理的 9.211 t/hm2 输入，和高水位线使用 16.335 kg/ 的效率(WUE )(hm2tain 危险是 25.7% 。第二等的危险的分发主要被地震紧张影响， activ 裘 ? 裘吗？？

英文摘要：

Optimal use of water and fertilizers can enhance winter wheat yield and increase the efficiencies of water and fertilizer usage in dryland agricultural systems. In order to optimize water and nitrogen （N） management for winter wheat, we conducted field experiments from 2006 to 2008 at the Changwu Agro-ecological Experimental Station of the Chinese Academy of Sciences on the Loess Plateau, China. Regression models of wheat yield and evapotranspiration （ET） were established in this study to evaluate the water and fertilizer coupling effects and to determine the optimal coupling domain. The results showed that there was a positive effect of water and N fertilizer on crop yield, and optimal irrigation and N inputs can significantly increase the yield of winter wheat. In the drought year （2006-2007）, the maximum yield （Yma~） of winter wheat was 9.211 t/hm2 for the treatment with 324 mm irriga- tion and 310 kg/hm2 N input, and the highest water use efficiency （WUE） of 16.335 kg/（hm2.mm） was achieved with 198 mm irrigation and 274 kg/hm2 N input. While in the normal year （2007-2008）, the maximum winter wheat yield of 10.715 t/hm2 was achieved by applying 318 mm irrigation and 291 kg/hm2 N, and the highest WUE was 18.69 kg/（hm2.mm） with 107 mm irrigation and 256 kg/hm2 N input. Crop yield and ET response to irrigation and N inputs followed a quadratic and a line function, respectively. The optimal coupling domain was determined using the elas- ticity index （El） and its expression in the water-N dimensions, and was represented by an ellipse, such that the global maximum WUE （WUErnax） and Ymax values corresponded to the left and right end points of the long axis, respectively. Considering the aim to get the greatest profit in practice, the optimal coupling domain was represented by the lower half of the ellipse, with the Yma~ and WUE~ax on the two end points of the long axis. Overall, we found that the total amount of irrigation for winter wheat should not exceed 324 ram. In addition