Is degradable plastic film alternative? Insights from crop productivity enhancement and soil environment improvement

Currently, it is unclear whether degradable film mulching is a feasible viable alternative to non-degradable film mulching for improving crop productivity and soil environmental conditions. In the present study, a three-year-long field experiment was conducted to evaluate the effects of three alternative degradable films and a traditional plastic film (PF) on soil properties and peanut growth performance. Results showed that degradable films enhanced peanut yields by 6.0-14.3% compared to no mulching (CK), while reduced the peanut yield compared to PF. The results of the structural decomposition model analysis attributed the positive correlations between peanut yields and soil temperature, soil organic carbon, soil alkali-hydrolyzable nitrogen, soil microbial biomass carbon (MBC), and soil microbial biomass nitrogen (MBN). The degradable films decreased soil temperature, soil organic matter, soil alkali-hydrolyzable nitrogen content, MBC and MBN content by 0.12-11.8%, 1.40-10.9%, 1.90-9.91%, 2.31-13.2% and 12.7-34.2% compared to PF, respectively, despite they performed better effects on soil environment than CK. Moreover, the degradation rates of the three degradable films ranged from 7.38% to 91.3%. The aliphatic polyester polylactic acid-based film was found to be the best alternative because of improvement of soil environment and crop yield as well as superior degradation properties.