PBAT全生物降解地膜的田间应用效果研究

Study on the Field Application Effect of PBAT Biodegradable Plastic Film

为筛选适宜南方地区的番薯专用全生物降解地膜,以番薯品种“一点红”为供试材料,设置3种全生物降解地膜、普通聚乙烯(PE)地膜和不盖膜5个处理,采用傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)、差示扫描量热仪(DSC)探究了全生物降解地膜在番薯田间覆盖过程中结构、形态和性能的变化。通过测定番薯的农艺性状和产量指标,研究不同处理对秋植番薯生长和产量的影响。结果表明:3种全生物降解地膜在宏观上表现显著降解效果,其失重率为40.78%~64.22%,降解进程与番薯生长与结薯过程基本吻合。FTIR显示:在光氧化、水解、酶解等的作用下,聚对苯二甲酸-己二酸丁二醇酯(PBAT)分子链发生了断裂,地膜发生降解;SEM图像显示:随降解间延长,地膜表面逐渐出现裂纹和孔洞结构。DSC结果显示:PBAT的降解会先发生在无定形区,结晶度增大,导致其玻璃化温度(Tg)和熔点(Tm)有所升高。3种全生物降解地膜的降解速度对比结果为:#8037>#8039>#8038。全生物降解地膜在秋植番薯覆盖应用上,不会影响番薯生长及结薯,其中,#8039的降解速度更吻合番薯生长阶段,产量最高。全生物降解地膜具有良好的降解特性,可有效解决农田残膜污染,有利于改善农田生态环境,建议选用#8039全生物降解地膜替代普通聚乙烯(PE)地膜,在广东省秋植番薯生产上推广应用。

Experiment was conducted with variety“Yidianhong”of sweet potato,five kinds of mulching material cultivation mode were set,including three kinds of biodegradable plastic film,polyethylene plastic film and without any film,to screen the special biodegradable plastic film suitable for sweet potato in South China.Fourier transform infrared spectroscopy(FTIR),scanning electron microscope(SEM)and differential scanning calorimeter(DSC)were used to investigate the changes of structure,morphology and characteristics of biodegradable plastic film.The effects of different treatments on the growth and yield of autumn-planting sweet potatoes were studied by measuring the agronomic traits and yield indexes.The results showed that three kinds of biodegradable plastic film had significant degradation effect with weight loss rate ranging from 40.78%to 64.22%,and the degradation process was basically consistent with the growth and formation process of sweet potato.FTIR showed that PBAT molecular chain was broken and the film degraded under the action of photooxidation,hydrolysis and enzymatic hydrolysis.SEM images showed that cracks and holes gradually appeared on the surface of the film with the degradation.DSC showed the degradation of PBAT would first occur in the amorphous region,leading to an increase in crystallinity,which caused an increase in its glass transition temperature(Tg)and melting point(Tm).The comparison results of degradation rate of three kinds of biodegradable plastic films were#8037>#8039>#8038.The application of biodegradable plastic film in autumn-planting sweet potato would not affect their growth and formation,and the degradation rate of#8039 is consistent with the growth stage of sweet potato with highest yield.Biodegradable plastic film has good degradation effect,could solve the pollution of farmland residual film,and is conducive to improving the ecological environment of farmland.The#8039 biodegradable plastic film could be used to replace ordinary PE film and promoted its application in the production of autumn-planting sweet potato in Guangdong Province.