Assessment of the Agricultural Effectiveness of Biodegradable Mulch Film in Onion Cultivation

This study conducted a comprehensive evaluation of the effects of biodegradable (BD) mulching film in onion cultivation, with a focus on plant growth, yield, soil environment, weed suppression, and film degradation, in comparison to conventional polyethylene (PE) film and non-mulching (NM) treatment across multiple regions and years (2023–2024). The BD and PE films demonstrated similar impacts on onion growth, bulb size, yield, and weed suppression, significantly outperforming NM, with yield increases of over 13%. There were no consistent differences in soil pH, electrical conductivity, and physical properties in crops that used either BD or PE film. Soil temperature and moisture were also comparable regardless of which film type was used, confirming BD’s viability as an alternative to PE. However, areas that used BD film had soils which exhibited reduced microbial populations, particularly Bacillus and actinomycetes which was likely caused by degradation by-products. BD film degradation was evident from 150 days post-transplantation, with near-complete decomposition at 60 days post-burial, whereas PE remained largely intact (≈98%) during the same period. These results confirm that BD film can match the agronomic performance of PE while offering the advantage of environmentally friendly degradation. Further research should optimize BD film durability and assess its cost-effectiveness for large-scale sustainable agriculture.