翻耕深度对膜下滴灌棉花生长和冠层小气候的影响

为探究翻耕深度对覆膜滴灌农田小气候及棉花生长的影响机制，于2019年4—10月在新疆库尔勒地区开展田间试验，设置20、30、40 cm 3组翻耕深度处理(T20、T30、T40)，以免耕处理(NT)作为对照，分析了翻耕深度对土壤孔隙率、农田耗水量、田间小气候、棉花生长状况及产量的影响。结果表明：翻耕深度的增加能够有效提高土壤孔隙率、增加膜内耕层土壤温度、促进植株耗水；棉株从膜内土壤中消耗的水分对冠层小气候的调控作用大于膜外土壤的水分蒸发对冠层小气候的调控作用，NT、T20、T30、T40处理膜内位置的农田耗水量分别是膜外位置农田耗水量的2.48、2.52、3.08、3.47倍；全生育期内，T20、T30、T40处理的农田耗水量分别是NT处理的1.30、1.42、1.52倍；深翻导致农田耗水量的增加能够有效提高冠层湿度，延长棉花生育期，使棉花增产。全生育期内，各翻耕处理(T20、T30、T40)的近地表平均冠层湿度分别比NT处理高12.83%、14.49%、17.55%，棉花全生育期分别比NT处理长10、16、23 d，籽棉产量分别比NT处理高670.68、1 252.67、1 584.02 kg·hm^-2。

Effects of tillage depth on cotton growth and canopy microclimate under mulched drip irrigation

To explore the effect of tillage depth on microclimate and cotton growth under mulched drip irrigation, field trials in Korla of Xinjiang, China carried out from April to October 2019. Three tillage depths of 20 cm, 30 cm, 40 cm (T20, T30, T40) and no tillage (NT) as a control were set up. The effects of tillage depth on soil porosity, farmland water consumption, field microclimate, cotton growth and cotton yield were analyzed. The results showed that the increase of tillage depth effectively increased soil temperature of inner\|membrane tillage layer and promoted plant water consumption. The controlling effect of the water consumed by cotton plants from the soil in the membrane on the canopy microclimate was greater than that of the soil water evaporation outside the membrane on the canopy microclimate. The total farmland water consumption in NT, T20, T30 and T40 treatments in the membrane was 2.48, 2.52, 3.08 and 3.47 times of that outside the membrane, respectively. During the full cotton growth period, the total farmland water consumption of T20, T30 and T40 treatments was 1.30, 1.42 and 1.52 times than that of the NT treatment, respectively. The increase of farmland water consumption caused by deep tillage effectively increased the canopy humidity, prolonged cotton growth period and increased cotton yield. During the whole growth period, the average canopy humidity near soil surface of tillage treatments (T20, T30, T40) was 12.38%, 14.49% and 17.50% higher than that of NT treatment, respectively, and the whole growth period of cotton were 10d, 16d, 23d longer than the NT treatment, respectively. The cotton yield was 670.68 kg·hm^-2, 1 252.67 kg·hm^-2, 1 584.02 kg·hm^-2 higher than those of NT treatment. The results of this study are of great significance for understanding the mechanism of tillage measures to improve cotton yield in Xinjiang, China.