The knowns, known unknowns and unknowns of sequestration of soil organic carbon

► Soil has great potential to become a managed sink for CO2 in agroecosystems. ► Increasing the SOC pool is also beneficial to secure soil fertility. ► This review discusses perspectives and practices to sequester more soil carbon. ►It also highlights methods and models used to estimate soil carbon pools. ► This knowledge and technology underpins decisions to protect the soil resource.