限量单次补灌对套作冬小麦产量的影响

Effects of Limited Single Drip Irrigation on Yield of Winter Wheat Intercropped with Spring Maize

在作物生长的不同时期分别对各处理进行了35mm限量单次滴灌．测定了土壤水分、籽粒产量及产量构成要素千粒重、穗粒重、株高等，并计算了水分利用效率和土壤水势。结果表明，小麦灌浆期限量单次滴灌对套作冬小麦增产效果最好．水分利用效率亦是如此。套作小麦灌水处理大多数产量构成要素及其它经济性状表现出明显差异。回归分析发现．WUE与籽粒产量间的关系可用幂函数来描述：WUE=-12．262＋0．276Ye^1/2（R^2=0．912^＊＊，p〈0．05）。土壤水势是降雨量和补灌量的函数。灌水后的第2个测定生育期所有套作小麦2个土层土壤水势均高于未灌水处理．且30～60cm土层土壤水势比0～30cm土层下降更为剧烈。

A field experiment was conducted for maize-intercropped winter wheat （Triticum aestivum） in 2002/2003 to evaluate the effects of limited supplemental drip irrigation on yield performance and water use efficiency（WUE）of intereropped winter wheat. An accurately controlled 35 mm of single drip irrigation was performed in different stages of wheat growth. Soil water content, grain yield and its components such as thousand--grain weight, number of grain, grain weight per spike, and plant height were recorded. The WUE and soil water potential were also estimated. The results show that limited single drip irrigation in grain filling had the best effect on yield increase of intereropped wheat, so was WUE. All the intereropped wheat in irrigated treatments showed obvious difference among most of their yield components and other economic traits. Regression analysis indicated a power relationship between WUE and Ye, which could be described as WUE=-12. 262＋0. 276Ye^1/2 （R^2 =0. 912^＊＊ , p〈0.05）. Soil water potential fluctuated as a function of the precipitation and supplemental irrigation. After irrigation, in the following measured stages the soil water potentials in the upper two layers in all plots of intercropped wheat were much higher than that not irrigated, and soil water potential in 30-60 cm depth decreased more sharply than those of 0-30cm.