| This article has been：Browse 2082Times Download 3602Times |
scan it! |
|
|
| DOI：:10.13522/j.cnki.ggps.2019337 |
|
| The Impact of Soil Moisture on Degradation of Biodegradable PBAT Mulching Films |
|
WU Si, GAO Weichang, CAI Kai, JIAO Jiaguo, ZHANG Shixiang
|
|
1. College of Resources and Environmental Sciences/Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China; 2. Guizhou Academy of Tobacco Science, Guiyang 550001, China;3. Zhengzhou Tobacco Research Institute of China National Tobacco Corporation, Zhengzhou 450001, China
|
| Abstract: |
| 【Background】There had been a steadily increase in use of mulching plastic films to boost crop yield by keeping top soil warming and moist while in the meantime preventing weed growth. However, most plastic films used in agriculture are slow or not biodegradable and their continuous use has resulted in plastic pollution. One mitigation is to use biodegradable mulch films, one of which is the Aliphaticearomatic biodegradable copolyester, poly-butylene adipate-co-terephthalate (PBAT) films. While PBAT biodegradable films are mechanically and thermally durable, the response of their degradation to soil environmental change is obscure.【Objective】This paper presents the results of an experimental study on change in degradation of PBAT mulching film under different soil moisture contents.【Method】The experiment was conducted in lab under three soil moistures: 15%, 25% and 35%; degradation of four PBAT biodegradable films were investigated. In each treatment, we measured the degradations rate, soil microbial and enzymatic activities in the soil.【Result】Films containing PBAT degraded in the soil. Scanning electron microscope (SEM) images showed large numbers of micro holes in the films after 130 days of incubation, and the carbonyl groups index increased as the experimental time elapsed. When soil moisture was the same, the change in microbial and enzymatic activities in soil amended with the four films was ranked in film A> film B> film C> film D, consistent with the degrading rate measured for each film, indicating that microbial decomposition was the dominant degrading process. Microbial and enzymatic activities under moisture of 15% and 25% were comparable, both being higher than that under 35% (P<0.05), indicating that the difference in microbial and enzymatic activities was instigated by soil moisture.【Conclusion】PBAT mulch films degraded in soil and the degradation was fastest when soil moisture was 25%. Soil moisture and the interior 3D structure of the film are the main factors that affect the film degradation. Choosing the biodegradable mulch film for a field needs to consider the soil moisture change to ensure that the film does degrade but not too fast to compromise its service or too slow to leave residuals. |
| Key words: soil moisture; PBAT biodegradable film; degradation characteristics |
|
|
