河西绿洲灌区制种玉米产量和水分利用效率对灌水量与灌水时期的响应OA

This study investigated the responses of seed maize yield and water use efficiency to irrigation amount and irriga-tion timing,so as to provide a basis for high water-efficiency production of seed maize in the oasis irrigation area.In 2023,field experi-ments were conducted in Liangzhou District of Wuwei City with low irrigation treatments(2 100,2 700,and 3 000 m3/ha),medium irri-gation treatments(3 300 and 3 600 m3/ha),and a high irrigation treatment(4 800 m3/ha).In 2024,field experiment was further carried out on 3 seed maize varieties with different maturity types,namely Yingde 77,Wuke 19,and Yudan 185,by reducing irrigation at the silking stage,middle grain-filling stage,and late-grain-filling stage.Results indicated that within the irrigation range of 2 100 to 4 800 m3/ha,the yield of seed maize showed an increasing quadratic function relationship with both evapotranspiration(ET)and irrigation amount(I).The maximum yield was achieved when the irrigation amount was 4 374.8 m3/ha and evapotranspiration was 5 910.8 m3/ha.Under low-water,the average yield decreased by 12.8%relative to that in the high-water treatment(4 800 m3/ha).However,there was no significant difference in yield between the medium-water treatments and the high-water treatment.With the increase in irrigation amount the ET amount in the maize field increased correspondingly,but the irrigation water use efficiency(IUE)and water use efficien-cy(WUE)of seed maize exhibited a decreasing quadratic function relationship.Compared with normal irrigation amount(4 050.0 to 4 875.0 m3/ha),when the irrigation amount was reduced by half during the silking stage and mid grain filling stage of seed maize,yield decreased by 23.8%and 12.0%,respectively,and IUE decreased by 17.3%and 4.8%,respectively.However,when an equivalent re-duction in irrigation was applied during the late grain filling stage,the differences in yield and IUE were not significant.The declines in yield and IUE of seed maize varieties with different maturity types were greatly affected by water deficit at different irrigation stages.Compared with the normal irrigation amount,when irrigation was reduced by half at the silking stage,the yield of the medium-matur-ing variety Wuke 19,the early-maturing variety Yingde 77,and the late-maturing variety Yudan 185 decreased by 40.1%,15.1%,and 19.2%,respectively.The IUE of the medium-maturing variety Wuke 19 decreased by 16.5%,whereas that of the early-maturing variety Yingde 77 and the late-maturing variety Yudan 185 was close to that under normal irrigation.Additionally,reduced irrigation significantly affected the agronomic traits of seed maize ears.Water deficit at the silking stage,middle-grain-filling stage,and late-grain-filling stage resulted in shorter ear length,increased barren tip length,and decreased grain weight per ear and 100-kernel weight,with the effect being particularly obvious when irrigation was reduced at the silking stage.Therefore,under the irrigation range and climatic conditions designed in this experiment,reducing irrigation significantly affects the yield and water use efficiency of seed maize,and water deficit during the silking stage has the greatest impact on yield.Medium irrigation during the growth period(3 300 and 3 600 m3/ha)or implementing mild water deficit during the late-grain-filling stage can achieve synergistic improvement in both yield and irrigation water use efficiency,thereby enabling water-saving and efficient production of seed maize.