ASHS 2024 Conference

The rise in the use of agricultural plastic mulch films raises environmental concerns, necessitating sustainable alternatives. Despite acknowledged benefits, the widespread adoption of biodegradable mulch over traditional plastic mulch remains a topic of debate. This review employs a comparative life cycle assessment perspective to explore the interplay between environmental impact and economic considerations associated with the production, use, and end-of-life of plastic and biodegradable mulch films. It also postulates impact mitigation strategies for mulch use in agroecosystem. Overall, biodegradable mulch films demonstrate superior merits in energy use and greenhouse gas emissions, but often contribute more to eutrophication, acidification, and land-use occupation compared to plastic mulch films. Environmental burden was found to vary based on polymer type, life cycle stage, end-of-life strategy, fertilizer application, additive content, film thickness, and climate. The manufacturing stage for both mulch types significantly contributed to greenhouse gas emissions and energy use, while plastic mulch film post-use stage contributed to human toxicity, ecotoxicity, eutrophication, acidification, GHG emissions, and photochemical effects depending on the end-of-life choices and adsorbed waste content. Energy and material recovery options are major strategies to mitigate post-use impacts, with recycling being preferable, albeit with the need to address eutrophication and human toxicity. Both mulch types increase yield, but deposited plastic mulch film residue creates soil health problems. On all fronts, biodegradable mulch films, especially starch-derived films, are more environmentally justifiable replacement for plastic mulch films, but higher production costs hinder widespread adoption. From an alternative perspective, straw mulch is a promising replacement for plastic mulch films in dryland areas due to yield, cost, and GHG reduction advantages. However, prevention of open burning and minimizing N-fertilizer applications to reduce N2O releases must be considered. The choice between plastic and biodegradable mulch films, therefore, requires a holistic assessment considering specific contextual nuances. This review elucidates these intricacies from economic, agronomic, and environmental viewpoints, providing an unbiased decision-making tool for agronomists, farmers, mulch film manufacturers, recyclers, and policymakers.