有限灌溉对绿洲春玉米农田耗水特征及水分利用效率的影响

Effect of Limited Irrigation on Water Consumption and Water Use Efficiency of Spring Maize in Desert Oasis Field

为了探究有限灌溉对绿洲沙地春玉米农田耗水特征及水分利用效率的影响,利用中子仪结合烘干秤重法连续监测了河西走廊荒漠绿洲沙地春玉米不同生育期农田土壤水分动态,分析了玉米农田日耗水量动态与土壤蒸散及作物水分利用效率。结果表明,整个生育期除播种-五叶期和拔节-孕穗期外,所有有限灌溉处理及充分供水对照间日耗水量均无显著差异（P〉0.05）,各生育时段内日耗水量随生育过程呈由小到大再由大到小的变化趋势,其峰值出现在吐丝—灌浆中期且高达6.8~10.0mm/d。灌水最少但产量最高的有限灌溉处理MI1全生育期蒸散量仅次于灌水较多的处理MI5。对照CK全生育期蒸散量远高于MI5,增幅达16.0%,而以MI3最低。水分利用效率以MI1和MI3最高,且与其他处理及对照间差异显著（P〈0.05）。水分利用效率以MI4最低,MI1和MI3水分利用效率均比MI2、MI4、MI5和CK显著提高19.3%,34.1%,15.3%和25.4%。MI1与其他所有处理及对照间、MI3与其他所有处理及对照间灌溉水利用效率差异显著,且以灌水最少但产量最高的MI1最高,以MI4最低。处理MI1灌溉水利用效率分别比MI2、MI3、MI4、MI5及CK显著提高35.1%,14.6%,61.0%,36.7%,48.4%,而MI3比MI2、MI4、MI5、CK分别显著提高17.9%,40.4%,19.3%,29.4%,MI5比MI4则显著提高17.7%。因此,有限灌溉能提高绿洲玉米水分利用效率和灌溉水利用效率,但有限灌溉对作物水分利用效率和灌溉水利用效率提高的促进作用并不具有稳定性。

In order to determine the effect of limited irrigation on water consumption and water use efficiency of spring maize field in newly cultivated sandy land in desert oasis of Hexi Corridor,the dynamics of soil moisture at various crop growth stages of maize were continuously monitored using soil neutron probe combined with drying-weighing method,and daily water consumption,soil evapotranspiration,and crop water use efficiency were also analyzed.The results indicated that no significant（P0.05）difference was found in daily water consumption among treatments except during sowing to Five-leaves and jointing to booting,and daily water consumption varied from low to high then to low during plant growth,the maximum value appeared during silking to middle filling with 6.8mm/d to 10.0mm/d.The seasonal evapotranspiration（ET）in treatment MI1 which yielded the highest under the least seasonal irrigation was slightly lower than in MI5 under more irrigation water.Among all the treatments,the ET in CK was 16.0% higher than in MI5,with the lowest in MI3.Water use efficiency（WUE）of maize was the highest in MI1 and MI3,and there were significant（P0.05）differences between these two treatments and the others.The lowest WUE was found in MI4,and the WUE was significantly increased by 19.3%,34.1%,15.3%,and 25.4% both in MI1 and MI3than in MI2,MI4,MI5 and the CK.There were significant differences in the irrigation water use efficiency（IWUE）between MI1 and the other treatments and CK,so were between MI3 and the other treatments and CK.The highest IWUE occurred in MI1 with the least seasonal irrigation but the highest grain yield,while the lowest IWUE appeared in MI4.In all the treatments,IWUE was significantly improved by 35.1%,14.6%,61.0%,36.7% and 48.4% in MI1 than in MI2,MI3,MI4,MI5,and the CK respectively,andIWUE was significantly improved by 17.9%,40.4%,19.3%,and 29.4%in MI3 than in MI2,MI4,MI5,and the CK,while 17.7% of IWUE was improved in MI5 than in MI4.Therefore,limited irrigation could improve WUE and IWUE of maize in oasis irrigation field.However,the effect of limited irrigation on WUE and IWUE improving was not absolutely stable.