Integrated Organic–Inorganic Fertilizer Management: Enhancing Crop Productivity, Soil Health, and Greenhouse Gas Mitigation

Integrated nutrient management (INM) is increasingly recognized as a promising approach for sustaining crop productivity while reducing some of the environmental impacts associated with intensive agricultural production. This study presents a structured narrative review with critical evidence synthesis of the published literature examining the effects of INM on crop productivity, soil health, and greenhouse gas emissions. Relevant studies were identified through structured searches of Scopus, Web of Science, and Google Scholar, covering publications from January 2000 to December 2025. Eligible studies included peer-reviewed field and controlled experiments evaluating the combined application of organic and inorganic nutrient sources across cereal, legume, and vegetable production systems under diverse soil types, climatic conditions, and agroecological regions. The findings show that INM has been associated with improvements in crop yield, soil health, and nutrient use efficiency across many production systems; however, the magnitude of these responses varies with crop type, soil properties, climate, organic input quality, and management practices. Reported yield improvements of approximately 15–25%, reductions in N2O emissions of 15–30%, and decreases in global warming potential of 11–24% represent ranges reported in the reviewed literature rather than pooled effect estimates. Evidence from long-term field experiments further indicates that INM can increase soil organic carbon, improve soil structure, and enhance biological indicators of soil health, although responses are not uniform across all agroecosystems. In flooded rice systems, for example, improvements in greenhouse gas intensity may occur alongside methane–nitrous oxide trade-offs, highlighting the importance of evaluating both agronomic and environmental outcomes.