Recycling fly ash from coal or biomass combustion for nutrient recovery and enhanced food production in acidic agroecosystems: A multi-level meta-analysis – ScienceDirect.com June 4, 2025 Power (Coal Ash) Recycling fly ash from coal or biomass combustion for nutrient recovery and enhanced food production in acidic agroecosystems: A multi-level meta-analysis ScienceDirect.com