Impacts of different water supplied conditions on root distribution, yield and water utilization efficiency of winter wheat

Field experiments were conducted at Luancheng Station, Chinese Academy of Sciences in different precipitation years. The impacts of water supplied conditions on root distribution, yield and water utilization efficiency(WUE) of winter wheat under different irrigation treatments were analyzed in order to supply a basis for optimum irrigation mode which could increase the yield and improve water utilization efficiency. The results indicated that most roots were concentrated in the upper 80 cm soil layer, and the density of roots declined exponentially downward with the increase of the soil layer depth. Considering water consumption in different soil layers, and the relationships among yield, water utilization efficiency and total water consumption, the optimal irrigation mode in North China plain was put forward, i.e., no irrigation in rain-full years, one time irrigation at jointing stage in normal years and two times at jointing stage and booting stage in dry years with the suitable water quota of 60 to 75 mm each time, which not only increased the winter wheat yield, but also benefited to using the deep soil water and improving the water utilization efficiency.