有限供水对夏玉米产量及其水分利用效率的影响

THE EFFECT OF LIMITED WATER SUPPLY ON THE YIELD AND WATER USE EFFICIENCY OF SUMMER CORN

在人工控制水分的测试坑条件下，对玉米全生育期的研究表明；随供水量减少则根系耗水深度明显加深，土壤各层次含水量变化较大。当供水量从适宜供水下降到中度亏缺供水时，则耗水深度由８０ｃｍ增加到１２０ｃｍ；在各生育期蒸腾速率，光合速率及产量和水分利用效率均随供水量的下降而下降；研究单叶水分利用效率表明：顶层第二叶在各叶层中最高；其日变化是９：００－１１：００时单叶ＷＵＥ最高。

Summer corn in all growth period was studied under the control water condition in artificial-pit. The result showed that the change of water contents of all soil layer is more and depth of con-sumption water is clearly increased, as water supply decreased ,when water supply decreased fromsuitable to middle deficit,depth of consumption water is increased from 80 cm to 120 cm。Tran-spiration rate,photosynthetic rate, yield and water use efficiency are decreased,as water supplydecreased. The single leaf WUE was studied,the result showed that the second leaf from topis thehighest in all leaf layers,9:00一11:00 is the highest in a day.