Biodegradable plastic mulches: Impact on the agricultural biotic environment

The increasing use of plastic films for agricultural mulching continues worldwide. Mulching improves crop yield, decreases pesticide' inputs to the field, saves irrigation water and contributes to tackle the food demand for the growing world population. However, plastic mulching results in polyethylene residues that contaminate agricultural soils and contribute to the massive worldwide plastic pollution, a serious environmental concern. Biodegradable plastic mulches (BDM) have emerged as a promising alternative to alleviate polyethylene pollution. BDM, made of different polymers and compositions, are designed to biodegrade in situ, into the agricultural soil. Their use may entail environmental impacts for the agricultural system that deserve to be explored on the short and on the long-term. This review discusses emerging findings on the impact of BDM on agroecosystem organisms, with special emphasis on cultivated plants and on soil organisms. The relevance of the material composition is highlighted by some reports evidencing specific BDM to alter development of cultivated plant species and to modify soil microbiome on the short-term (spanning a few months); model organisms may also be affected. Long-term studies have not yet been attempted. In-depth studies focused on the effects of the diversity of BDM on agroecosystem organisms are urgently required to identify low-impact BDM materials and to guarantee advanced agriculture in a sustainable environment. (C) 2020 Elsevier B.V. All rights reserved.