不同地膜的降解特征及其对旱区马铃薯生长和土壤微环境的影响

Degradation Characteristics of Different Films and Their Effects onPotato Growth and Soil Microenvironment in Arid Region

为筛选适宜宁南旱区马铃薯生长且对土壤环境友好的降解地膜类型,以不覆盖为对照,研究普通塑料膜、秸秆纤维地膜、生物降解膜的降解特征及其对马铃薯生长、土壤微环境的影响。结果表明,生物降解膜和秸秆纤维膜分别在播后90和60 d进入诱导期,生物降解膜和秸秆纤维膜均在播后150 d进入碎裂期;播后150 d的地膜质量损失率以秸秆纤维地膜最高,而普通塑料膜无明显变化。播后60 d,生物降解膜和秸秆纤维膜处理土壤蓄水量分别较对照显著提高21.4%和10.3%,而普通塑料膜处理与对照差异不显著。播后90~120 d,秸秆纤维膜和生物降解膜处理平均土壤温度分别较对照显著增加1.2和0.8℃。播后150 d,与对照相比,普通塑料膜和秸秆纤维膜处理土壤速效磷、速效钾含量提升效果显著。秸秆纤维膜处理细菌数量最高,而生物降解膜处理真菌和放线菌数量最高。播后150 d马铃薯地上部和地下部干物质累积量均以生物降解膜处理最高,马铃薯株高、茎粗和增产效果均以秸秆纤维膜处理最为显著。主成分分析结果表明,土壤细菌、放线菌数量是影响地膜降解的主要因素,而播后30~60 d土壤水分和播后60~120 d膜质量损失率对马铃薯产量形成至关重要。综上,秸秆纤维地膜降解效果优于普通塑料膜,且对改善旱地土壤微环境效果显著,可实现马铃薯增产,可代替普通地膜应用于旱作马铃薯生产中。本研究结果对筛选适宜宁南旱区农业可持续发展的最佳地膜类型具有一定的现实意义。

In order to screen out degradable film types suitable for potato growth and friendly to the soil environment in the dry-farming areas of southern Ningxia,a field experiment was conducted to study the degradation characteristics of common plastic film,straw fiber film and biodegradable film and their mulch effects on potato growth and soil microenvironment.Without film mulch was used as the control check.The results showed that biodegradable film and straw fiber film entered the induction period at 90 and 60 DAS(day after sowing),respectively,and both biodegradable film and straw fiber film entered the fragmentation period at 150 DAS.At 150 DAS,the straw fiber film had the highest rate of film mass loss,while common plastic film had no obvious changed.At 60 DAS,compared with the control,the biodegradable film and straw fiber film significantly increased soil water storage capacity by 21.4%and 10.3%,respectively,whereas the common plastic film hadn’t significant difference.Compared with the control,average soil temperatures at 90 to 120 DAS was significantly increased by 1.2℃and 0.8℃with the straw fiber film and biodegradable film,respectively;the straw fiber film and common plastic film treatments significantly increased the soil available phosphorus and potassium contents at 150 DAS.The highest number of bacteria was found in the straw fiber film treatment,while the highest number of fungi and actinomycetes was found in the biodegradable film treatment.The highest aboveground and belowground dry matter accumulation of potato at 150 DAS was found in the biodegradable film treatment,and the straw fiber film treatment had the highest potato plant height,stem thickness and yield.The result of principal component analysis showed that,the number of soil bacteria and actinomycetes were the main factors affecting film degradation,while soil moisture from 30 to 60 DAS and the rate of film mass loss from 60 to 120 DAS were crucial to the formation of potato yield.In conclusion,the degradation effect of straw fiber film was better than that of common plastic film,which remarkable improved the soil microenvironment,and could increase potato yield.The straw fiber film could instead of common mulch film in dryland potato production.The results of this study provide a certain practical significance for the screening of the best film type for the sustainable development of agriculture in the dryland of southern Ningxia.