地膜覆盖有增温、保墒、通气、促肥、保土壤疏松等作用 ,因此 ,地膜覆盖棉花和露地棉花相比有早发苗、早结铃、有效结铃期长等优点。但由于其根系发达分布浅 ,抗旱能力差 ,所以后期易发生早衰现象。加之吐絮期间 ,省内棉区又常因秋旱 ,使根系吸收作用和叶片光合作用受阻 ,故常 Film mulching has the effects of increasing temperature, preserving soil moisture, aerating, promoting fattening and preserving soil looseness. Therefore, mulching cotton and open-field cotton have the advantages of early-onset seedling, early bolting and long effective bolting period. However, due to its well-developed root distribution, poor drought resistance, so prone to premature aging phenomenon. In addition, during the bolting period, cotton fields in the province were often obstructed by autumn drought and the root absorption and the photosynthesis of the leaves were blocked.