摘要:为解决当前农田大量残膜污染问题，设置3种不同降解速率的氧化生物双降解地膜（降解a、降解b、降解c）和普通塑料地膜覆盖及露地对照5个玉米种植试验，研究氧化生物双降解地膜田间降解性能（降解率、拉伸强度和断裂伸长率）及其对土壤水热、玉米生长状况及产量的影响。结果表明：1）不同降解速率氧化生物双降解地膜降解梯度与预期基本相符，3种降解速率的地膜全生育期降解率分别为14.2%、10.0%和6.5%，差异达显著水平。降解a、降解b和降解c地膜在田间覆盖120 d后，垄上地膜拉伸强度损失率分别为30.4%、20.3%和19.1%，断裂伸长率损失率为10.4%、13.5%和5.0%，垄侧地膜拉伸强度损失率为59.0%、50.7%和45.6%，断裂伸长率损失率为71.7%、55.6%和51.0%，其中降解a拉伸强度和断裂伸长率与降解b和降解c相比均达显著差异水平，且垄侧各降解地膜机械性能损失率显著大于垄上地膜。2）氧化生物双降解地膜显著提高了玉米生育前期5~25 cm层土壤温度和0~40 cm层土壤含水率，与露地相比，降解a、降解b和降解c处理下5~25 cm土层平均温度分别提高了4.5℃、4.4℃和4.4℃，0~40 cm土层含水率分别提高了3.2%、2.9%和2.2%。3）氧化生物双降解地膜加快了玉米生育进程，使玉米植株提前3 d出苗，缩短生育期5~7 d，且玉米株高和叶面积指数均显著高于露地处理，略优于普通地膜。4）在产量构成和最终产量方面，氧化生物双降解地膜与普通塑料地膜覆盖均较露地处理增加了玉米穗长、穗粗及百粒重，降解a、降解b、降解c和普通地膜处理较露地对照增产率分别达14.3%、14.3%、10.4%和13.2%。研究认为，氧化生物双降解地膜覆盖具有明显的增温保墒效应，与普通地膜相同，能够显著提高玉米产量，并且可以通过改变配方调节其降解速率。本研究成果可为氧化生物可降解地膜替代普通地膜及其在东北地区推广应用提供科学依据。
关键词:氧化生物双降解地膜/
降解性能/
土壤温度/
土壤水分/
玉米生长发育/
玉米产量
Abstract:The growing use of plastic film in agriculture has significantly increased crop production as it positively enhances the soil environment. However, the massive disposal of this material has as well increased environmental risk. One way to solve this problem is by developing a substitutable mulching film such as biodegradable ?lms that are ultimately convertible into water, carbon dioxide and soil organic matter by micro-organisms. Oxo-biodegradable plastic film is a newly developed biodegradable film that can increase soil water, soil temperature and crop yield and it also has satisfactory degradation properties. In this study, series of experiments were conducted to determine the degradation properties (degradation rate, tensile strength and elongation) of oxo-biodegradable plastic films and the effects of different mulching treatments on soil moisture, soil temperature, maize growth and maize yield. The mulching experiment was conducted using three kinds of oxo-biodegradable plastic films with different ingredients and different degradation rates (Degradation a, Degradation b and Degradation c) and common plastic film, and using un-mulched field as the control. Maize was ridge-cultivated and films covered all soil surface. The results showed that:1) biodegradation rate of different oxo-biodegradable films met soil and crop requirements for high yield production. Degradation rates of Degradation a, Degradation b and Degradation c after maize harvesting were respectively 14.2%, 10.0% and 6.5%. While the tensile strength on the ridge tops of Degradation a, Degradation b and Degradation c were decreased respectively by 30.4%, 20.3% and 19.1%, elongation decreased by 10.4%, 13.5% and 5.0% under mulching in the field for 120 days. Meanwhile, tensile strength of side ridges decreased respectively by 59.0%, 50.7% and 45.6% for Degradation a, Degradation b and Degradation c and elongation by 71.7%, 55.6% and 51.0%. Decrease in degradation was significantly different for different films. Furthermore, decrease in degradation properties of the film on ridge side was significantly more than that on the top of ridge. 2) Compared with the control, oxo-biodegradable plastic film mulching significantly increased soil temperature in the 5-25 cm soil layer and soil moisture in the 0-40 cm soil layer on early maize growth period. Degradation a, Degradation b and Degradation c treatments increased average soil temperature in the 5-25 cm soil layers respectively by 4.5℃, 4.4℃ and 4.4℃. Soil moistures under Degradation a, Degradation b and Degradation c treatments were increased respectively by 3.2%, 2.9% and 2.2% in the 0-40 cm soil layer. 3) Oxo-biodegradable plastic film mulching promoted maize growth, enhanced early maize emergence and shortened overall growth period by 5-7 days. Also the height and LAI of maize under oxo-biodegradable plastic film mulching were significantly higher than those under un-mulched treatment and slightly better than that under common plastic film mulching. 4) Compared with the control treatment, three oxo-biodegradable plastic films and common plastic film treatments increased ear length, ear diameter and 100-kernel weight of maize. At the same time, Degradation a, Degradation b and Degradation c and common film treatments significantly increased maize yield by 14.3%, 14.3%, 10.4% and 13.2%, respectively. Based on the study, oxo-biodegradable plastic film mulching significantly increased soil temperature and moisture and enhanced maize yield more than common film mulching, with degradation rate adjustable by changing ingredients. The results provided scientific basis for the replacement of common plastic films by oxo-biodegradable plastic films and for the development, popularization and application of oxo-biodegradable plastic films in Northeast China.
Key words:Oxo-biodegradable plastic film/
Degradable property/
Soil temperature/
Soil moisture/
Maize growth/
Maize yield
? Equal contributors
注释:
1) ?同等贡献者
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