可降解地膜降解性能及对棉花生长的影响

Degradation Performance of Degradable Plastic Films and Their Effects on Cotton Growth

为了解决棉田使用PE地膜导致土壤污染问题,探讨可降解地膜的降解性能及对土壤水分、温度和棉花生长的影响。进行了3种可降解(氧化-生物降解)地膜、普通地膜和露地栽培棉花对比试验,设置5个处理,3次重复。结果表明:3种可降解地膜降解速率及强度不同,当季质量损失率达26.06%~79.96%,降解效果明显;降解诱导期相差15 d左右,具有一定可控性,降解后地膜残片变薄、变脆并紧贴地面,继续起到一定的增温、保墒作用。棉花地膜覆盖与露地栽培相比,播种后50 d内日平均地温提高2~3℃,单株结铃增加1.3个,铃重增加0.7 g,籽棉产量增加583.5 kg/hm2,达显著水平。可降解地膜覆盖与PE地膜覆盖栽培相比,对土壤温度、水分的影响差异不显著,籽棉产量无显著差异。以氧化-生物双降解地膜替代普通地膜应用于棉花覆盖栽培具有可行性。

To study the degradation properties of degradable mulch films and their influences on soil moisture,soil temperature and cotton growth and solve farmland soil pollution resulting from ordinary agricultural mulch film used in cotton field,an comparative experiment of cotton cultivation were conducted with 5 treatments and 3 replicates using biodegradable(oxidized-biodegradable)mulching,common mulching and no mulching.The results showed that the degradation rate and strength of the three degradable films were different and the weight loss rate was 26.06%-79.96%in the year,and the degradation effect was remarkable.Difference of degradation induction period was about 15 days,and was somewhat controllable.The residual film fragmentation after degradation was thin,crisp and close to the ground surface and continued to play a role in increasing soil temperature and keeping soil moisture.Compared with no film mulching treatment,film mulching increased average soil temperature daily by 2-3℃within 50 days after sowing,increased cotton bolls per plant by 1.3,increased boll weight by 0.7 g,increased the unginned cotton yield by 583.5 kg/ha.The effects of degradable mulch film and common PE membrane on soil moisture and soil temperature were equal and the unginned cotton yield had no significant difference when cotton are covered by degradable film and common PE membrane.It is feasible to use oxo-biodegradable plastic films instead of common plastic film for agricultural production.