Influence of different management practices on carbon sequestration of agricultural soils - a review

Climate change and greenhouse gas emissions (GHGs) are critical environmental issues of the 21st century. The increase in atmospheric GHGs concentration since the Industrial era induced interest in identifying practices to reduce these gases and soil C sequestration could be the best solution for reducing CO2 enrichment of the atmosphere. However, the C sequestration capacity of soils is influenced by various management technologies like reduced tillage, organic amendments, cover cropping, nutrient management and biochar. A significant amount of SOC could be sequestered by farm yard manure (FYM) application which enhances lignin and lignin-like molecules that are crucial components of resistant C pools. Legume-based crop rotation promotes C sequestration by accumulating C in macro-aggregates. Biochar causes a positive effect on soil aggregation and SOC storage through the release of multivalent ions. C sequestration depends profoundly on stabilizing the added C through appropriate management practices. The C stabilization mechanism can be better understood following the fractionation of C in different pools. The recalcitrant C pools stored in micro-aggregates represent C sequestration, while C stored in macro-aggregates is C accumulation and a short-term concept. Therefore, this review aims to identify the best management practices leading to C build-up, besides improving C stabilization by imparting recalcitrance to SOC.