Evaluation of biodegradable mulch films as alternatives to plastic mulching in sustainable agriculture

Plastic mulch films boost crop yields by conserving moisture and suppressing weeds, but they leave behind persistent residues that degrade soil structure and pollute farmland across the tropics. This research compared four biodegradable mulch alternatives PLA/PBAT blend, starch-based, paper, and PHA-based films against Conventional Polyethylene (PE) in a 24-week okra field trial at the University of Ibadan Teaching and Research Farm between March and August 2023. All biodegradable films maintained soil moisture within 87-94% of PE performance during the first 12 weeks. Paper mulch degraded fastest, losing 78.3% of its mass by week 24, while PHA-based film retained the most integrity at 41.7% mass loss. Okra yield under PLA/PBAT (14.8 t ha⁻¹) did not differ from PE (15.3 t ha⁻¹, p>0.05). Soil temperature was positively correlated with degradation rate across all biodegradable types (r = 0.71-0.84). Results suggest that PLA/PBAT blends offer the best balance between agronomic performance and post-season biodegradation for humid tropical vegetable systems.