Nutrient enrichment of food waste compost using agricultural residues

Abstract

Food waste (FW) management is a critical global challenge due to its environmental and economic impacts. Composting provides a sustainable recycling pathway but FW alone often requires supplementation with carbonrich residues to balance moisture and enhance compost quality. This study investigated the effects of cocomposting FW with dried coffee grounds, soybean meal (SM), banana peel, and light rubber wood ash (LA) in different proportions (0–20% w/w) for 14 days in foam box systems. The objective was to identify the additive and concentration that most effectively improved the nutrient composition of the obtained compost. Results showed that agricultural residues significantly increased macronutrient levels. In particular, 20% SM yielded the compost with the highest nutrient concentrations, with total N, P₂O₅, and K₂O reaching 3.39%, 1.77%, and 2.89% (w/w), respectively, compared with 1.51%, 0.93%, and 0.61% (w/w) in the control. LA enhanced compost alkalinity and K₂O content. These findings demonstrate that SM and LA are promising additives for producing a nutrient-rich compost from FW that could contribute to sustainable waste management and the development of high-quality organic fertilizers.