Greenhouse Gas Emissions in Rice Agroecosystems: Impacts, Mechanisms, and Mitigation Approaches

ABSTRACT

Rice paddies are significant sources of greenhouse gases (GHGs), including methane (CH ₄ ), nitrous oxide (N ₂ O), and carbon dioxide (CO ₂ ), making them a major contributor to agricultural GHG emissions. These emissions exacerbate climate change, which subsequently threatens global food security. This review synthesizes current understanding of the biogeochemical and microbial processes regulating GHG emissions from rice agroecosystems and critically evaluates established and emerging mitigation strategies. CH ₄ emissions are primarily governed by anaerobic conditions, carbon availability, and methanogenic activity, whereas N ₂ O emissions are regulated by nitrogen availability, nitrification–denitrification processes, and water–nitrogen interactions. CO ₂ emissions mainly arise from soil respiration, organic matter mineralization, and agricultural inputs. Among the available mitigation options, alternate wetting and drying, optimized nitrogen and residue management, low‐emission cultivars, conservation practices, and precision agriculture offer considerable potential to reduce emissions while sustaining rice productivity. Emerging approaches, such as genome editing, rhizosphere engineering, and artificial intelligence, may provide additional mitigation opportunities but require rigorous field‐scale validation. Future research should prioritize integrated mitigation strategies, GHG trade‐offs, long‐term field studies, and economically viable approaches suitable for diverse rice‐growing systems.