Biopolymers Providing Enhancement of Soil Nutrients by Mulching: A Review

This review discusses the potential and actual use of biopolymers as replacements for petrochemical-based ones in the fabrication of mulching films, providing soil nutrient enhancement and, more generally, improved crop health. In agriculture, mulching, i.e., covering the soil with a protective layer of material, is a key practice to improve productivity. Films based on polyolefins have been traditionally employed for this purpose, extending the mulch’s lifespan, due to their durability and UV resistance. However, an increasingly popular approach involves applying biodegradable films to be tilled into the soil, where they will break down naturally over time. Another significant trend is the current use of nanoparticles and proteins to further enhance mulch function: nanoparticles increase the rate of nutrient delivery while controlling mulch breakdown. In terms of approaching a circular economy model, the transition of refuse into secondary raw matter for mulching represents an essential route, by repurposing yard waste, food scraps, and agricultural leftovers as organic mulches.