Daily variation of transpiration rate and WUE of maize under controlled root-divided alternative drip irrigation were studied through potted experiment in order to investigate water saving mechanism and effect of the new irrigation method. The result indicated that daily variation of transpiration rate of maize showed same asymmetric shallow ＂M＂ type and the change range of a. m. was higher than that of p. m on the fine day in AI1 and CK disposal, while it showed symmetrical ＂M＂ type, which took 12：00 as axial, in AI2 disposal. As to the daily average transpiration rate, All was as much as that of CK and the absolute difference was only 0. 01 mmol/（m^2·s）, which showed that AI1 could reduce the quantity of irrigation while maintain the transpiration rate. Compared with CK, the transpiration of AI2 was merely 89. 5% of CK. Though the yield WUE of AI2 was higher than CK, ifs biology yield reduced clearly, merely 89. 5% of CK Not only the yield WUE of AI1 was higher than CK, but also its biology yield had little difference with CK. All of the data proved that controlled root divided alternative drip irrigation was a practicable water ,saving technology.
Water Saving Irrigation
controlled root-divided alternative drip irrigation