Analysis of Water Use Efficiency for Winter Wheat and Summer Maize Cropland in Weishan Irrigation District

Seasonal change and control factors of WUEfor winter wheat and summer maize cropland were analyzed using measured data at Weishan eco-hydrologic flux station established by Tsinghua University.Results showed that when the water use efficiency was defined as the ratio of GPPand ET,the seasonal WUEof wheat and maize were 2.81 and 4.81gC/(kg.H2O),respectively.While the water use efficiency was defined as the ratio of GPPand ET/ET0,the seasonal WUEET0of wheat and maize were 10.6 and 16.3gC/m2,respectively.Seasonal variation of WUE was significant,and WUE was major influenced by vapor pressure deficit and photosynthetically active radiation,while WUEET0 was major influenced by LAI.