Recent advances in soil carbon sequestration and emission reduction within legume green manure enhanced rotation systems: a review

Prolonged intensive agricultural practices have caused substantial losses of soil carbon and nitrogen pools, contributing to soil degradation and increased greenhouse gas emissions, thereby posing significant threats to agricultural sustainability. Crop rotation represents a crucial agricultural practice for maintaining soil sustainability and promoting long-term soil health. Well-designed crop rotation systems can effectively maintain soil fertility, enhance agricultural resource utilization efficiency, and mitigate greenhouse gas emissions, thereby generating significant ecological and economic benefits. The integration of legume green manure into rotations offers particular promise due to its nitrogen fixing capacity and soil health benefits. However, owing to the inherent complexity of soil systems and their multifunctionality, a comprehensive theoretical framework for soil carbon sequestration and emission reduction within legume green manure rotation systems remains to be established. This review systematically examines the impact of legume green manure on key factors and processes controlling soil carbon dynamics and greenhouse gas emissions within rotation systems. We synthesize current knowledge on the underlying mechanisms and identify critical research gaps. Future research should focus on the following key aspects to advance our understanding and application of legume green manure in rotation systems: (i) clarifying the synergistic physico-chemical-biological mechanisms of soil carbon sequestration mediated by legume green manure; (ii) investigating the impact of legume green manure on carbon sequestration and emission reduction in deep soil layers; (iii) enhancing quantitative analysis of carbon-nitrogen cycling dynamics using advanced techniques like isotope tracing; (iv) conducting comparative studies on regional variations in the effects of legume green manure; and (v) advancing mechanization and precision management technologies for legume green manure integration. • 、 Carbon sequestration mechanism of legume green manure driven rotation system. • 、Analysis of the carbon emission reduction mechanism driven by legume green manure. • 、The role of soil properties in carbon sequestration and emission reduction. • 、The limitations of legume green manure in crop rotation systems.