Reaching carbon neutrality is not possible without a significant contribution of land-based measures via managing sinks and sources in soils in agriculture and forestry. Agricultural soils have a major role to play as they have lost huge amounts of organic C since the advent of agriculture and have a large potential to sequester additional carbon. The European Union has ambitious climate change objectives, that require to put C sequestration into practice. The European Joint Programme SOIL “Towards climate-smart sustainable management of agricultural soils developed a roadmap for soil research to foster soil organic carbon sequestration that contributes to climate change mitigation. In the 24 countries participating in EJP SOIL a thorough national stakeholder consultation was performed. The consulted stakeholders comprised representatives from all soil stakeholder groups among which academics, policy makers, NGO’s and farmer organisations. They ranked the preservation and increase of soil organic carbon as the main challenge for agricultural soil management in Europe and analysed the related knowledge availability and use as well as barriers and opportunities to reach aspirational targets. The identified knowledge development needs concerned four thematic areas: (i) understanding soil organic carbon sequestration; (ii) evaluating agricultural soil management options in their ability to store additional carbon, to close nutrient cycles and avoid additional GHG emissions, and to maintain other expected ecosystem services; (iii) developing options for measuring, reporting and verifying SOC sequestration including with high throughput methodologies and (iii) analysing the conditions that enable the implementation of SOC sequestering options by land managers. These knowledge developments must be accompanied by better harmonization, organisation and storage of soil data, by knowledge sharing and transfer via training, capacity building and networks development among stakeholders and by knowledge application in particular in the policy area.