深松耕作下灌溉定额对棉田水分利用效率及产量的影响

【目的】研究深松耕作下灌溉定额对新疆南疆滴灌棉田棉花生长发育及水分利用效率和产量的影响,优化新疆滴灌棉田灌水制度,为新疆南疆地区棉花生产实现高效用水,节水保产提供理论依据。【方法】2019年,深松40 cm条件下,设置2 400 m³/hm²(W₁)、3 000 m³/hm²(W₂)、3 600 m³/hm²(W₃)和4 200 m³/hm²(W₄)4个滴灌定额的田间试验,测定并分析不同滴灌定额对棉花生长发育、水分利用效率及产量的调节效应。【结果】深松40 cm条件下,棉花株高和叶面积指数均随灌溉定额的增加呈线性增大趋势,W₃和W₄处理株高与叶面积指数显著高于W₁处理;灌溉定额的增加,促进生育后期生物量的形成,有利于产量提高,但灌溉定额过大,反而不利于生物量积累与产量形成,不同处理生物量累积表现为W₃>W₂>W₄>W₁的变化规律,且W₃处理显著高于W₁处理(P<0.05),分别较W₁、W₂和W₄处理高出18.8%、9.6%和13.9%;增加灌溉定额,各生育期0~80 cm土层内土壤含水量均呈递增变化趋势,但灌溉量过大,容易造成水分下渗;对于产量性状而言,W₃处理单株结铃数显著较W₁处理增加10.9%,W₂和W₃处理籽棉产量显著高于W₁和W₄处理(P<0.05),W₂处理分别较其他处理高出10.9%、0.6%和11.8%;水分利用效率随灌溉定额的增加显著降低(P<0.05),处理间均达到显著性差异。【结论】深松40 cm条件下,当灌溉定额在3 000~3 600 m³/hm²,更有利于促进棉花生长发育和干物质积累,能更好的平衡水分利用与产量的关系,利于产量形成。

Effects of Irrigation Quota on Water use Efficiency and Yield of Cotton Field under Subsoiling Tillage

【Objective】 To explore the effects of irrigation quota on cotton growth and development, soil moisture distribution, water use efficiency and yield under subsoiling tillage in southern Xinjiang, optimize the irrigation system of drip irrigation cotton field in Xinjiang, which provided a theoretical basis for optimizing the irrigation system of drip irrigation cotton field and realizing efficient water use, water saving and increase production in southern Xinjiang.【Methods】 Therefore, a cotton cultivation field positioning drip irrigation quotas experiment was carried out under the condition of subsoiling 40 cm from April to October of 2019 in Awati County experimental base of the arid inland Tarim Basin, Northwest Xinjiang, four drip irrigation quotas of 2400 m³/hm²(W₁),3,000 m³/hm²(W₂),3,600 m³/hm²(W₃)and 4,200 m³/hm²(W₄) were set,aiming to explore the effects of different drip irrigation quotas on cotton growth and development, water use efficiency (WUE) and the growth characteristics and crop productivity in cotton growing seasons.【Results】 Under the condition of 40 cm subsoiling, the plant height and leaf area index of cotton increased linearly with the increase of irrigation quota,The plant height and leaf area index of W₃ and W₄ treatment were significantly higher than that of W₁ treatment; The increase of irrigation quota promoted the formation of biomass in the later growth stage and was conducive to the increase of yield,but the excessive irrigation quota was not conducive to biomass accumulation and yield formation.The biomass accumulation of different treatments showed the change of W₃ > W₂ > W₄ > W₁, and W₃ treatment was significantly higher than W₁ treatment (P<0.05), which was 18.8%, 9.6% and 13.9% higher than W₁, W₂ and W₄ treatment respectively; With the increase of irrigation quota, the soil water content in each growth period showed an increasing trend in 0 ~ 80 cm soil layer, but too much irrigation was easy to cause water infiltration;However, excessive irrigation is easy to cause water infiltration; For yield and component factors, The number of bolls per plant in W₃ treatment was significantly higher than that in W₁ treatment by 10.9%, the yield of seed cotton in W₂ and W₃ treatment was significantly higher than that in W₁ and W₄ treatment (P<0.05), and the yield of seed cotton in W₂ treatment was 10.9%, 0.6% and 11.8% higher than that in W₁, W₂ and W₃ treatment, respectively; Water use efficiency decreased significantly with the increase of irrigation quota (P<0.05), and there were significant differences among different treatments.【Conclusion】 When the irrigation quota is in the range of 3,000-3,600 m³/hm², it is more conducive to promote cotton growth and development and dry matter accumulation, better balance the relationship between water use and yield, and facilitate yield formation, Under the condition of 40 cm subsoiling.