Effect of irrigation frequency during the growing season of winterwheat on the water use efficiency of summer maize in a doublecropping system

摘要

Our aim was to investigate the potential effects of irrigation frequency during the growing season of winter wheaton the water use efficiency (WUE) of summer maize in a double cropping system. To this end, we conducted afield experiment with winter wheat cultivated with 1, 2, and 3 irrigation applications with 120 mm water at the timeof stem elongation, heading, or milking. The results showed that later irrigation applications increased soil moisture before sowing (SMBS) of summer maize. Summer maize grain yield was enhanced in both the common andexcessively rainy years with increased SMBS; however, irrigation during the later growing season of winter wheatin rainy years could increase deep percolation of summer maize. In common and rainy years, the more the SMBS,the higher was the grain yield of summer maize. The highest WUE for summer maize was obtained when it wasgrown after winter wheat irrigated with 120 mm water at milking or 60 mm water at each, the stem elongation andheading stages. Considering the combined WUE of winter wheat and summer maize, the authors think that winterwheat should be irrigated at the stem elongation and heading stages to achieve reasonable WUE and grain yieldfor both crops.