为探明北疆地区膜下滴灌棉花主要生育期适宜的土壤水分阈值,在蕾期、花铃期、吐絮期设置了3 个土壤水分阈值区间包括(50%~80%)FC(FC为田间持水量)、(60%~90%)FC和(70%~100%)FC组成正交试验,并以当地农户灌溉为对照组(CK),定量分析了各生育期土壤水分阈值对棉花生长指标、耗水规律和产量的影响.结果表明:各生育期土壤水分阈值为(50%~80%)FC时,W1 处理棉花株高、茎粗、叶面积指数(LAI)、地表干物质积累量均较 CK 处理显著降低了 26.8%、22.0%、37.1%、14.3%(p<0.05),全生育期耗水量较 CK 处理减少了37.2%.W6 处理的单株铃数和籽棉产量均最高(6.41 个、5 848.99 kg/hm2),W4 处理的水分利用效率(WUE)最高(1.28 kg/m3),W9 处理的单铃重最高(5.41 g),W5 处理衣分最高(42.51%),分别较 CK 处理增加了 10.9%、10.1%、21.9%、1.5%、3.1%.基于熵权-TOPSIS的综合评价结果表明W6处理最优,建议北疆地区膜下滴灌棉花蕾期、花铃期和吐絮期土壤水分阈值分别设为(60%~90%)FC、(70%~100%)FC和(50%~80%)FC.
In order to determine the suitable soil moisture threshold for the main growth stages of cotton under mulched drip irrigation in northern Xinjiang,three soil moisture threshold intervals((50%-80%)FC(FC is the field water capacity),(60%-90%)FC and(70%-100%)FC)were set up during the bud stage,flowering and boll stage,and boll blowing stage.An orthogonal experiment was conducted,and local farmers'irrigation scheme was used as a control(CK)to quantitatively analyze the effect of soil moisture threshold on cotton growth indicators,water consumption and yield during each growth stage.The results showed that at(50%~80%)FC,cotton plant height,stem thickness,leaf are-a index(LAI)and above-ground dry matter accumulation of treatment W1 were significantly reduced by 26.8%,22.0%,37.1%,and 14.3%(p<0.05),respectively,and water consumption in the whole growth period was reduced by 37.2%compared with the treatment CK.The treatment W6 produced the highest number of bolls and seed cotton yield(6.41,5 848.99 kg/hm2);W4 had the highest water use efficiency(1.28 kg/m3);W9 scored the highest weight of single bolls(5.41 g);W5 presented the highest cotton lint percentage(42.51%).The above indicators of individual treatments were increased by 10.9%,10.1%,21.9%,1.5%and 3.1%,respectively,compared with CK treatment.The com-prehensive evaluation results of entropy weight-TOPSIS indicates that W6 is the optimal treatment.It is suggested that the suitable soil moisture thresholds for the bud stage,boll stage and boll blowing stage of cotton under mulched drip irrigation in northern Xinjiang are(60%-90%)FC,(70%-100%)FC and(50%-80%)FC,respectively.