北疆滴灌棉花的可降解地膜安全期研究

Probe into Degradable Plastic Film Mulching during Cotton Safety Period under Drip Irrigation in Northern Xinjiang

【目的】明确棉田地膜覆盖安全期,研究不同降解地膜对滴灌条件下土壤温度、水分、棉花产量的影响。【方法】设置5个处理,3次重复,T1~T4处理为降解地膜处理,T5为普通地膜处理。【结果】铺设第85 d(7月17日)T1处理地膜已完全降解,而T2处理地膜部分降解,T3处理地膜在第130 d(8月31日)刚发生降解,T4地膜未降解。各处理对土壤温度的增幅在4月、5月、6月分别为55.4%~62.6%、14.3%~23.5%、9.6%~14.2%,7月没有增温效应;而降解地膜的保水性能与其厚度、降解速率无关,其中T4处理保水性最好;地膜铺设85 d前降解的地膜降解时间与棉花生长发育及产量成反比,而85 d后仍未降解的地膜T3、T4、T5处理对棉花产量无显著差异。【结论】降解地膜降解时间在85 d后,即棉花花期以后可有效发挥土壤增温效应,达到稳产的效果。

[ Objective ] To make clear plastic film mulching cotton safety period and study the effects of different degradation films on soil temperature, moisture and the yield of cotton under drip irrigation. [ Method] The experiment set up 5 treatments with 3 repeated times, T1 -T4 treatment was for the degradation of plastic film processing, and T5 was for ordinary plastic film processing. [ Result] The results showed that： the laying of eighty -fifth days （July 17th） T1 treatment, plastic film was completely degraded and only partially degraded by T2 treatment. However, degradation began after 130 days （August 31 ） later by T3 treatment. T4 treatment made no degradation at all. The soil temperature was increased in April, May and June between 55.4% - 62.6%, 14.3% - 23.5% and 9.6% -14.2%, by all treatments, in July it did show warming effect; and water retention performance of the membrane was not associated with its thickness and degradation rate, among them, T4 treatment produed the best water retention. Plastic film was laid 85 days ago, the plas- tic film degradation time was inversely proportional to cotton growing development and yield. And 85 days lat- er, the film was not degraded by T3, T4 and T5 treatment, which showed no significant difference in cotton yield. [ Conclusion] In summary, the plastic degradation time 85 days after the cotton flowering period can effeetively exert the soil warming effect to achieve the stable production.