不同灌水次数对夏玉米生长发育及水分利用效率的影响

Effects of Different Irrigation Times on Growth and Water Use Efficiency of Summer Maize

通过防雨棚下测坑试验,研究了不同灌水次数对夏玉米形态指标、产量、耗水量以及水分利用效率的影响。结果表明,夏玉米株高和叶面积指数随灌水次数的减少而降低;拔节期不灌水明显抑制株高和叶面积的增长。果穗长、果穗粗、穗粒数有随着灌水次数的减少而降低的趋势;灌4水的产量最高,在苗期和灌浆期灌水(2水)的处理产量最低,较灌4水的处理减产45.38%,而灌抽雄水(3水)的处理产量都较高,减产幅度均低于8%;夏玉米的阶段耗水量和全期耗水量随灌水次数的减少而减少;任一生育阶段不灌水均会导致该阶段日耗水量的降低,并对以后阶段的日耗水产生一定的后效影响。通过对各处理夏玉米的水分敏感指数和水分利用效率综合分析,确定夏玉米抽雄期和拔节期为需水关键期,在农田水分管理中应优先满足;在华北平原可推行灌2～3水的节水灌溉技术,即在自然降水偏多年份灌2水,正常偏少年份灌3水。

The effects of different irrigation times on growth and water use efficiency（WUE） of summer maize were studied with irrigation treatments on summer maize（Zea mays L.）grown under a rain shelter.The results showed that height and leaf area index（LAI）of summer maize decreased with the number of irrigation reduced and non-irrigation at jointing stage significantly inhibited plant height and LAI.The components of yield including ear length,ear diameter and kernel number showed falling trend with decrease in the number of irrigation.The treatment of 4 irrigations had the highest yield,and yield of the irrigation treatment at the seedling and filling stage（2 times） was the lowest with reduction of 45.38%,while the treatment of 3 irrigations including irrigation at tasselling stage could also get high output,with decline rate less than 8%.The water consumption of summer maize at each stage as well as the whole growth stage decreased with the reduction of irrigation number.Non-irrigation at either phase resulted in reduction of daily water consumption in this phase,and had some after-effects on subsequent stages.Analyses of maize moisture sensitivity index and WUE showed that the tasselling period and jointing stage were the critical periods of water demand,which should be given priority in the water management.The optimal irrigation schedule was irrigation 3 times in a normal or less precipitation year or 2 times in more precipitation year at the whole growth stage of summer maize in North China Plain.