节水灌溉对夏玉米蒸腾效率的影响

Effect of Water Saving Irrigation on Summer Maize Transpiration Efficiency

对高、中、低三个不同供水量下的夏玉米蒸腾效率研究结果表明，在强光照下，供水不足引起ＷＵＥ明显下降，而在弱光照下，不同供水量的ＷＵＥ相差不大，灌浆期复水后则差异消失。说明供水不足时ＷＵＥ由供水量和光照共同决定。这是由于在强光照下不同供水量之间Ｐｎ差异很大，Ｔｒ无差异，而在弱光照下，Ｐｎ无差异，Ｔｒ差别明显所致。在强光照下，供水４４５ｍｍ的ＷＵＥ明显高于供水３５０ｍｍ和２８０ｍｍ的ＷＵＥ；在弱光照下，上述三个供水量条件下的ＷＵＥ相近。

Transpiration efficiency of summer maize was studied in three water content level.This experiment revealed that WUE decreased significantly in higher light intensity under water supply deficit. But WUE didn't decrease in lower light intensity and when rewatering at seed filling stage,WUE was the same in three levels. The result indicated that WUE depend upon the amount of water supply and the light intensity. The relationships. between Pn, Tr and P were studied in the paper. In higher light Pn differed greatly and Tr remained the same.