Effects of Supplemental Irrigation Based on Soil Moisture Test on Water Consumption Characteristics,Water Potential of Flag Leaf,Grain Yield and WUE in Winter Wheat

To determine the effects of soil moisture content on water consumption characteristics and grain yield in wheat.Field experiment was conducted to examine the effects of soil moisture content on water use efficiency(WUE),water potential of flag leaf and grain yield of wheat(cv.Jimai 22).The irrigation treatments were designed based on relative content of soil moisture in 0-140 cm soil layer at pre-wintering,jointing,and anthesis stages,respectively as 80%,60% and 52% for W0;80%,70%,and 65% for W1;85%,70% and 65% for W2;80%,70% and 70% for W3;85%,70% and 70% for W4.The results showed the ratio of precipitation to total water consumption amount in treatment W2 was higher than that of treatment W3 and W4;the irrigation amount and the ratio of irrigation amount to total water consumption amount were presented from high to low as W4W2 or W3W1,whereas a opposite change occurred in the ratio of soil water consumption amount to total water consumption amount.Treatment W2 could adequately use precipitation and irrigation water,but the consumption amount of soil water was less than that of other treatments.Water potential and relative water content of flag leaves in treatment W2 had no significant differences with other treatments at early grain filling stage,but which were significantly higher than those of treatment W1 and W3 and no significant difference with W4 at late grain filling stage.The grain yield for treatment W2 and W4 was higher than the other treatments,but water use efficiency and irrigation benefit for W2 were higher than treatment W4.In conclusion,under the condition of this experiment,as far as water potential and relative water content of flag leaves,WUE and grain yield be concerned,the most appropriate irrigation regime recommended is treatment W2.