Advancing soil carbon sequestration solutions: A decision-support tool for achieving net-zero goals

Soil carbon sequestration (SCS) is a promising approach to mitigate climate change by enhancing carbon storage in soils while simultaneously improving soil functioning. Despite its potential, the effectiveness and sustainability of SCS strategies are highly variable, contingent on location-specific environmental and management contexts, and are often constrained by risks of reversibility and potential soil quality degradation. This underscores the urgent need for robust, data-driven frameworks to guide the prioritization and implementation of SCS strategies, ensuring long-term benefits while minimizing trade-offs.

This study introduces an innovative multicriteria decision-support tool designed to evaluate and prioritize SCS strategies in croplands, considering their carbon sequestration potential, environmental co-benefits, and socio-economic implications. A comprehensive review of 264 meta-analyses was conducted, focusing on the impacts of 13 SCS strategies, grouped into seven families: crop diversification, land management, mulching, organic amendments, fertilization, biochar application, and agri-technologies. The developed tool integrates seven key performance indicators (KPIs): ease of implementation, SOC increase potential, co-benefits, negative effects, costs, permanence of carbon in soil, and additional crop yield. The prioritization tool integrates quantitative and qualitative data into a scoring matrix, providing a robust framework to evaluate the multifaceted impacts of SCS strategies. It accounts for variability in data quality and uncertainty, allowing users to adapt the weighting of KPIs to align with specific goals. This allows the identification of Pareto-efficient strategies that maximize SOC sequestration while minimizing trade-offs, supporting the adoption of contextually relevant SCS strategies in agriculture.

Preliminary results highlight biochar application and agroforestry as promising strategies, with average SOC stock increases of 34% and 32%, respectively, followed by crop rotation (20%), fertilization techniques (16%), cover cropping (12%), and mulching (8%). Biochar demonstrates particularly high sequestration rates (0.03–66 MgC ha⁻¹ y⁻¹), alongside substantial improvements in soil properties, such as porosity, aggregate stability, and water-holding capacity, and a 25% average enhancement in crop productivity. By systematically synthesizing evidence and scoring SCS strategies across multiple dimensions, this study bridges the gap between theoretical knowledge and practical implementation of SCS strategies. The tool facilitates targeted decision-making, promoting research and investment in the most effective and sustainable practices, advancing the integration of soils into climate change mitigation strategies.