Soil Carbon Sequestration Potential of Climate-Smart Agronomic Practices: A Critical Review

Abstract

Agricultural soils can contribute to climate mitigation through management that increases organic carbon inputs, limits avoidable losses and sustains favourable conditions for carbon retention. Yet higher soil carbon concentrations, larger stocks relative to conventional management and additional atmospheric carbon removal are not interchangeable outcomes. This critical narrative review evaluates the sequestration potential of cover cropping, diversified rotations, residue retention, reduced tillage, organic amendments, biochar, balanced nutrient management, water management and agroforestry in predominantly mineral agricultural soils. Verified scholarly literature with publication coverage through 30 July 2026 was synthesised according to intervention mechanisms, measurement validity, temporal persistence and whole-system greenhouse gas consequences. The most consistent evidence supports maintaining or increasing plant-derived inputs and combining compatible practices, rather than assuming that disturbance reduction alone produces substantial whole-profile gains. Cover crops commonly increase topsoil carbon, but responses depend on biomass production, growing windows, water availability and nitrogen management. Imported amendments can enlarge receiving-soil stocks without demonstrating equivalent additional removal at landscape scale. Biochar offers a distinct persistence pathway, conditional on feedstock sourcing, production emissions and realistic decay accounting. Evidence on mineral-associated carbon clarifies mechanisms but does not convert unfilled stabilisation capacity into an immediately attainable mitigation budget. Apparent disagreement among studies frequently reflects differences in sampling depth, equivalent soil mass, controls, duration and the distinction between measured and modelled outcomes. Nitrous oxide, methane, displaced biomass uses and subsequent management reversals can materially change the climate balance. A defensible implementation strategy therefore separates soil restoration from offset certification, prioritises locally feasible management packages and combines repeated stock measurements with independently evaluated models. Long-term, multi-depth experiments that jointly measure carbon, greenhouse gases, yields and resource costs are the highest research priority. Soil carbon management is a conditional, finite and valuable complement to emissions reduction, not a substitute for it.