Impact of agricultural weathering on physicochemical properties of biodegradable plastic mulch films: comparison of two diverse climates over four successive years

Biodegradable plastic mulch films (BDMs) are essential in the production of vegetable and specialty crops due to their promotion of increased crop yield and quality. Unlike conventional polyethylene (PE) mulches, BDMs can be tilled into the soil after crop harvest to undergo biodegradation, thereby leading to minimal environmental impact. Agricultural weathering impacts both the performance of BDMs during crop production as a barrier to weeds and biodegradability of BDMs in the soil. To better understand the relative importance of climatic factors, the change of physicochemical properties of BDMs during single-season, 3-4 month, field trials for vegetable production at two diverse climates (Knoxville, TN and Mount Vernon, WA) across four successive years (2015-2018) was evaluated. Mulch treatments consisted of four commercially available BDMs composed primarily of polybutylene co-adipate- co-terephthalate (PBAT) that differed in color and polymeric feedstock, a black experimental BDM pr...