亏缺灌溉对南疆棉花生长和水分利用的影响

针对南疆地区水资源短缺、作物水分利用效率低等问题,以棉花为试验材料进行田间小区试验,在棉花现蕾期、开花期以及结铃期分别设置3个亏缺灌溉水平(W₁:50%ET_c,W₂:65%ET_c,W₃:80%ET_c,ET_c为作物蒸发蒸腾量),以全生育期100%ET_c灌溉处理为对照(CK),研究膜下滴灌条件下,不同生育期亏缺灌溉对棉花生长、产量、氮素吸收和水分利用效率的影响.结果表明:现蕾期亏水对棉花株高、叶面积指数、地上干物质生长、氮素吸收和产量有不同程度的抑制效应,但复水后补偿效应显著,其中轻度亏水(W₃)在籽棉产量减少3.48%的条件下,WUE高达1.57 kg/m³,显著高于CK的1.48 kg/m³;开花期亏水,棉花的各项生长指标均有显著降低,复水后补偿效应不显著,不利于棉花生长发育;结铃期亏水对棉花地上干物质累积、氮素吸收和产量均有显著的抑制效应,但在W₂和W₃水平下,WUE均达1.51 kg/m³.综合考虑在保证棉花产量的同时达到节水增产的目的,可在棉花蕾期进行80%ET_c灌水,其他生育阶段实施充分灌溉,来控制营养生长,促进生殖生长,获得更高的水分利用效率.

Effects of deficit irrigation on cotton growth and water use in southern Xinjiang of China

Aiming at the problem of the shortage of water resources and low water use efficiency of crops in the southern Xinjiang region, in this plot experiment,the cotton was used as the test species.Three irrigation levels(W₁:50%ET_c,W₂:65%ET_c,W₃:80%ET_c, ET_c is the crop evapotranspiration)were set in the cotton budding stage, flowering stage and bolling stage, controlled by 100% ET_c irrigation during the full growth period.The effects of deficit irrigation at different growth stages on cotton growth, yield, nitrogen uptake and water use efficiency under mulched drip irrigation were studied.The results show that the deficit irrigation at the budding stage has different degrees of inhibition on cotton plant height, LAI, above-ground dry matter growth, nitrogen accumulation and cotton yield, while the compensation effect was significant after rewatering.Among them, the cotton yield was reduced by 3.48% under the slight deficit irrigation(W₃), and the WUE was as high as 1.57 kg/m³, which was significantly higher than the CK treatment of 1.48 kg/m³.Deficit irrigation at the flowering stage, the growth indicators of cotton have been significantly reduced, and the compensation effect is not significant after rewatering, hindering cotton growth and development.Deficit irrigation at the bolling stage had a significant inhibitory effect on above-ground dry matter accumulation, nitrogen absorption and cotton yield,while the WUE reached 1.51 kg/m³ under the W₂ and W₃ levels. In comprehensive consideration of achieving the goal of saving water and increasing production while ensuring the cotton yield, the irrigation of 80% ET_c can be performed during the cotton budding stage, and fully irrigated during other growth stages to control the vegetative growth and promote the reproductive growth to obtain higher water use efficiency.