Short Communication: Liquid Organic Fertilizer from Coffee Waste

Coffee processing generates substantial volumes of organic waste (spent coffee grounds, pulp, husk, and silverskin) that present both environmental challenges and opportunities for agricultural valorization.This short communication synthesizes current research on converting coffee waste into liquid organic fertilizers (LOF) through methods including composting, fermentation, vermicomposting, and chemical extraction.Evidence indicates coffee waste-based liquid fertilizers can supply nutrients, biostimulants, and beneficial microorganisms while improving soil properties and supporting plant growth.However, standardization challenges, variable nutrient content, potential phytotoxicity, and limited field-scale validation remain barriers to widespread adoption.We briefly outline production methods, nutrient profiles, agronomic effects, environmental benefits, and key research gaps for commercial development.