新疆棉花双膜覆盖增温效应分析

【目的】为棉花双膜覆盖技术的推广提供可行依据。【方法】进行棉花双膜与单膜覆盖增温效应的对比分析。【结果】(1)双膜覆盖比单膜覆盖明显提高播种至出苗期间的0~20 cm耕层土壤地温,增加土壤有效积温,从播种至出苗期间双膜覆盖比单膜覆盖日平均地温高0.9℃,最低温差0.6℃,最高温差达到1.3℃;双膜覆盖较单膜覆盖累计增加土壤积温15.2℃。(2)双膜与单膜覆盖5 cm日平均地温温差1.4℃,最高温差达到2.4℃,比单膜累计增加地温24.3℃,5 cm土层正好是棉花种子所处的耕层,因此该土层地温的提高为播种后加速种子吸水、萌动提供了很好的温度环境,有效促进了棉花出苗。(3)双膜覆盖栽培还有效提高了一日4个时段(02:00、08:00、14:00、20:00)的土壤温度。【结论】(1)双膜覆盖比单膜覆盖有更好的增温效应。(2)双膜覆盖提高了不同土层土壤温度,且这种增温效应随土壤深度的增加而逐渐减弱,且土层间温差逐渐减小,这种增温效果明显高于单膜覆盖的增温效果。(3)随着时间的不同,土壤不同土层地温变化也发生着相应变化,反映出土壤的热传导效应。

Cotton Double Plastic Mulching Effect of Raising the Temperature in Xinjiang

【Objective and Method】Through a comparative analysis on the temperature raising effect of cotton double plastic mulching and single plastic mulching,the study hopes to provide practical basis for the extension of the double plastic mulching technology.【Result and Conclusion】The study confirmed that(1) Double plastic mulching has better temperature raising effect than single mulching,it can effectively increase the soil temperature at the depth of 0-20 cm from sowing to seed emergence period,and increases the soil effective temperature.From sowing to seed emergence,the average daily soil temperature of the double mulching is 0.9℃ higher than single mulching,and the lowest temperature difference is 0.6℃,and the highest temperature difference reaches 1.3℃.Compared with single mulching,double mulching can increase the soil accumulated temperature by 15.2℃.(2)Double mulching raises the soil temperature at different layers,and the temperature raising effect drops gradually with the increase of soil depth,and the temperature difference between layers reduces gradually,which is better than the temperature raising effect of single mulching.Double mulching with single mulching of 5 cm,the daily soil temperature difference reaches 1.4℃,and the highest temperature difference reaches 2.4℃.The accumulated increased temperature is 24.3℃ more than single mulching.5 cm soil layer is where the seeds are sowed,therefore the temperature increase of the soil layer provides a good temperature environment for the seed water absorption and germination after sowing,which also helps the cotton seedling.(3) Double mulching also effectively improves the soil temperature during four periods a day(at 02:00,08:00,14:00 and 20:00 respectively).With different time period,the soil temperature at different layers also changes accordingly,which reflect the effect of soil thermal conductivity.