Biochar application on agricultural land is promoted for its high permanence as a carbon sink. This study examines the spatiotemporal dynamics and economic net benefits of biochar sequestration in EU agricultural soils from 2020 to 2050. A discrete time dynamic economic optimization model, spatially disaggregated across 26 EU member states, evaluates trade-offs between using agricultural residues for biochar, bioenergy, direct soil incorporation, and cover crops. Results show that biochar will become economically viable within the next decade, with optimal carbon stocks reaching 0.6–6.8 tonnes per hectare by 2050. Countries with abundant biomass benefit most due to economies of scale and lower transport costs. By 2050, optimal carbon sequestration yields a net present value of about 212 billion euro, including 36 billion from biochar. Sensitivity analysis underscores the influence of carbon pricing, production costs, and regional biomass supply. Biochar thus offers a cost-effective, regionally variable mitigation option for the EU.