Effects of water and nitrogen deficit on yield and water use efficiency of spring wheat

Aimed at problems of limited water resources, high input of water and fertilizer in wheat production and low water use efficiency in arid irrigation area, influence of water and nitrogen deficit on water use efficiency of wheat was discussed, which provided certain basis for establishing theory of water efficient use of wheat．Taking two wheat varieties“Yongliang4”（YL4）and “Longchun41”（LC41）as plant materials, 4 treatments for each varieties were set, including two water irrigation treatments, one was full irrigation（W₁）in all growth stage, the other was deficit irrigation W₂（irrigated 65% of water demand for irrigation crops in jointing -booting stage and grain filling stage, irrigation at other growth stages was 100% of predicted crop water requirement of adequate irrigation treatment）, two nitrogen treatments N₁（local conventional nitrogen application, 220 kg/hm²）and N₂（reduced nitrogen application, 110 kg/hm²）．Effects of water saving and nitrogen reduction on water consumption characteristics and water use efficiency of wheat were studied．Results showed that water consumption of spring wheat was significantly reduced due to water deficit and nitrogen deficit, and effect of reduced nitrogen application on water consumption was not significant, but grain yield and water use efficiency were decreased．Water use efficiency of spring wheat was controlled by yield and water consumption and correlation was parabolic．Therefore, in arid irrigation areas, certain water and nitrogen regulation could be used to maintain yield while improving water use efficiency．