许冬 万鹏 褚世海 李儒海

摘要：【目的】研究小麦秸秆高量覆盖对长江流域棉田杂草防控及棉花产量形成的影响，为该区域棉田化肥和除草剂减量综合技术模式构建提供理论依据。【方法】以Bt抗虫棉GK19为试验材料，以无秸秆覆盖为对照（M0，CK），设3个小麦秸秆高量覆盖处理[15000 kg/ha（M1）、20000 kg/ha（M2）和30000 kg/ha（M3）]，观察棉田不同生育期内杂草防效、土壤含水量，以及棉花叶绿素含量、株高、果枝数、成铃数等农艺性状指标。【结果】小麦秸秆高量覆盖对棉田整个生育期内杂草种群均有很好的防控效果。秸秆高量覆盖可显著提高土壤含水量（P<0.05），并随秸秆覆盖量的增加整體呈上升趋势，其中，M0处理的棉田土壤含水量在棉花整个生育期基本维持在20.79%～21.70%，而小麦秸秆高量覆盖棉田土壤含水量可达26.25%～35.65%。小麦秸秆高量覆盖还可显著促进棉花的快速生长及提高叶片叶绿素合成，但随着秸秆覆盖量的增加其增长幅度不显著（P>0.05）。另外，小麦秸秆高量覆盖对提高棉花的果枝数、蕾数和成铃数也有显著促进作用，M0处理在吐絮期的果枝数和成铃数仅为8.0和10.7，而小麦秸秆不同高量覆盖处理可达12.2～13.2和25.9～29.9。【结论】长江流域棉花定苗后，一次性覆盖15000 kg/ha小麦秸秆可有效抑制全生育期内的棉田杂草，并对棉花生长及产量形成具有积极的调控作用，可有效降低化学除草剂及化肥的使用量。

关键词： 小麦秸秆覆盖;棉花;棉田杂草;土壤水分;生长发育;产量性状

中图分类号： S562                               文献标志码： A 文章编号：2095-1191（2021）05-1191-07

Abstract：【Objective】The effects of high dosage of wheat straws on weed control and cotton yield formation in Yangtze River Basin were studied，these works provided theoretical basis for integrated technique model of chemical fertilizers and chemical herbicides reductions in cotton field. 【Method】Taking insect-resistant cotton variety GK19 as material，the experiment was conducted involving three wheat straw mulching rates[15000 kg/ha（M1），20000 kg/ha（M2） and 30000 kg/ha（M3）]，and no straw mulch was the control（M0， CK）. The effects of high dosages straw mulching on weed control，soil moisture content，chlorophyll content，plant height，numbers of bud and bolls during the seedling stage，flowering and boll stage and boll-opening stage were measured. 【Result】The results showed that high dosages of wheat straw mulching could inhibit the germination of weeds during the whole growth periods. Compared with the non-straw returning treatment，high dosage wheat straw mulching significantly increased the soil moisture（P<0.05），and increased with the increase of wheat straw mulching. The soil water content of M0 field maintained at 20.79%-21.70% during the whole growth period of cotton，while that of wheat straw mulching treatments reached 26.25%-35.65%. Wheat straw mulching could also significantly promote the rapid growth of cotton and improve the chlorophyll synthesis of leaves，but with the increase of straw mulching，there was no significant effect on them（P>0.05）. In addition，high dosage wheat straw mul-ching significantly increased the numbers of branches，buds and bolls. The number of branches and bolls of the M0 treatments were only 8.0 and 10.7 at the boll opening stage，while the treatments of wheat straw could reach 12.2-13.2 and 25.9-29.9. 【Conclusion】Wheat straw mulching contributes to weed control and regulating the growth and development of cotton and yield formation by one-time application for 15000 kg/ha after seedling thinning in Yangtze River Basin，which can reduce the input of chemical herbicide and chemical fertilizer.

Key words： wheat straw mulching; cotton; weed in cotton field; soil moisture; growth and development; yield trait

Foundation item： National Key Research and Development Program of China（2017YDF0201900）; Agricultural Science and Technology Innovation Center Project of Hubei（2016-620-000-001-018）

0 引言

【研究意义】江汉平原是湖北省最大的棉花主产区和优质棉生产基地，也是我国长江中下游地区重要的商品粮基地。近年来，随着我国农业生产技术和水平的不断提高，小麦等作物产量逐年上升，秸秆作为农业生产中的一项重要副产品，其数量规模也随之持续增大（孙通等，2017）。有数据显示，2015年我国可收集利用秸秆总量高达6.41亿t，除大部分被用于秸秆还田、工业原料及生活燃料外，仍有1.5亿t秸秆资源被遗弃在田间地头或就地焚烧（崔蜜蜜等，2016）。……