Biodegradability and ecological impacts of polyethylene-based mulching film at agricultural environment

Discarded Polyethylene (PE) mulches have posed a persistent pollution in the agricultural field. Although PE degraded by microbes has been reported, the effect on in situ soil environment is not completely understood. To determine the biodegradability and ecological impacts of PE-based mulches, we tested the biodegradation related properties of screened strains and analyzed change in soil quality and microbial community after covering with different mulches. Strain Bacillus aryabhattai 5-3 showed 3.85 ± 0.50% gravimetric weight loss after a 30 days incubation with PE-based mulch as the sole carbon source; Considerable pits and vast cavities were found on the surface using AFM and SEM. The hydrophobicity of mulch sheet was decreased to 68.9 ± 0.8°, FTIR identified that new oxidized groups were formed on the surfaces of incubated mulch. Additionally, the fluctuations of microbial communities indicate that synthetic mulch could replace the current commercial product to minimise agricultural pollution.