Problems and Improvements of Plastic Mulched Drip Irrigation for Cotton Plantation in XinjiangFeasibility of Application for Combining Double Degradable Films Mulch with Subsurface Drip Irrigation

Plastic mulched drip irrigation technique（PMDIT）has been used widely in Xinjiang because of its high water and fertilizer use efficiencies，and feasible-to-be-mechanized operation in the field. However，lots of problems such as low emergence rate（resulted from the low temperature and soil crust near the film holes for the growth of cotton seedlings）。waste films pollution to the soils and weak adversity resistance（resulted from the shallow roots and high ratio of shoots and roots）were gradually found when using the PMDIT in the practical production.Based on analyzing and summarizing available research results and practical experiences，a technique，combining the double degradable films mulch with the subsurface drip irrigation，was put forward to solve the problems and improve the extensively used PMDIT at present in this study.Technique should be helpful for enhancing the emergence rate and adversity resistance ability of cotton，and reducing waste films pollution to the soils.However，some specific measures（for example，the mulching methods and determination of the degradation duration of the degradable films，and the rational irrigation schedule，etc.）related to the practical application of the technique need further research.