Abstract:

【Objective】 To study the mechanized cotton planting mode with equal row spacing of 76 cm, which is a new mechanized cotton planting mode, which is beneficial to chemical leaf defoliation and ripeness, and improves the picking efficiency and quality.In order to further clarify the pattern of water consumption and yield benefit, optimize and improve the supporting high yield technical measures, and provide a theoretical basis for improving the current supporting technology of 76 cm equal row spacing machine cotton picking.【Methods】 Based on the field experiment, three planting densities (low-density M₁, 135,000 plants/hm^2; Medium density M₂, 180,000 plants/hm²; To study the effects of high-density M₃, 225,000 plants/hm²) and irrigation quota [severe deficit W₁ (50% ETC), 3,150 m³/hm²; mild deficit W₂ (75% ETC), 4,050 m³/hm²; and fully irrigated W₃ (100% ETC), 4,980 m³ /hm²] on soil water distribution, water consumption characteristics, yield and water use efficiency in 76 cm machine-cut cotton field with equal row spacing.【Results】 Different planting densities and irrigation quotas had significant effects on soil water distribution.The distribution of water in the soil profile presents an overall pattern, and the soil water content increases with the deepening of soil layer.Under the same irrigation quota, the increase of density significantly increased the upper soil moisture content, which resulted in the increase of the overall water distribution uniformity.Under the same planting density, compared with the heavy deficit irrigation, full irrigation significantly increased the water consumption of cotton field, and significantly increased the water content of the underlying soil on the basis of the increase of the overall soil water content, resulting in the overall water distribution uniformity increased at first and then decreased.In addition, there were significant differences in yield and water use efficiency under different densities and irrigation quota.The combination of high density and heavy deficit irrigation had the highest water use efficiency, which reached 14.08 kg/(hm²·mm) and exceeded the simulated value by 10.18%.The cotton yield of low density and full irrigation combinations was the highest, but there was no significant difference between high density and heavy deficit irrigation combinations.【Conclusion】 Under the condition of comprehensive consideration of yield and water use efficiency, we concluded that the combination of 225,000 plants/hm² density and 3,150 m³/hm² irrigation quota was the most suitable planting pattern for mechanized cotton harvesting with 76 cm row spacing, which was beneficial to the improvement of cotton yield and water use efficiency.The results can provide a basis for the popularization and application of machine-picking cotton with equal row spacing of 76 cm, and also provide a reference for the combination of density and irrigation quota with irrigation conditions.

Key words: pick up cotton machine; plant density; lrrigation quota; 76 cm equal spacing; water distribution; water efficiency

摘要：

【目的】研究一种利于化学脱叶催熟、提高采摘效率和品质的新型机采棉种植模式,分析该种植模式的耗水规律与产量效益,优化和完善配套的高产技术措施,为完善现行76 cm等行距机采棉配套技术提供理论依据。【方法】 采用大田试验,设置3个种植密度(低密度M₁,13.5×10⁴株/hm²;中密度M₂,18×10⁴株/hm²;高密度M₃,22.5×10⁴株/hm²)和灌溉定额[重度亏缺W₁(50% ET_C),3 150 m³/hm²;轻度亏缺W₂(75% ET_C),4 050 m³/hm²;充分灌溉W₃(100% ET_C),4 980 m³/hm²],研究其对76 cm等行距机采棉土壤水分分布、耗水特征、产量及水分利用效率的影响。【结果】不同种植密度与灌溉定额均对土壤水分分布有显著影响。水分在土壤剖面中分布整体呈现,随土层加深土壤含水率越高;在相同灌溉定额下,密度增加显著增加了上层土壤含水率,致使水分整体分布均匀性升高。在相同种植密度下,相较于重度亏缺灌溉,充分灌溉显著增加了棉田耗水量,并在土壤整体含水率上升的基础上,显著增加了下层土壤含水率,水分整体分布均匀性呈先升高后降低趋势。不同密度和灌溉定额处理下产量和水分利用效率具有显著差异,以高密与重度亏缺灌溉组合水分利用率最高,达到14.08 kg/(hm²·mm),并且超过模拟值10.18%;以低密与充分灌溉组合棉田产量最高,但是与高密和重度亏缺灌溉组合之间差异不显著。【结论】密度22.5×10⁴株/hm²和灌溉定额3 150 m³/hm²组合是最适合76 cm等行距机采棉的种植模式,有利于棉田产量和水分利用率的提高。

关键词: 机采棉, 密度, 灌溉定额, 76 cm等行距, 水分分布, 水分利用率