Katarina Hedlund

Carbon sequestration in arable soils is gaining increasing attention in global policymaking initiatives for climate-change mitigation. Large-scale assessments of soil organic carbon development in arable land are affected by the scarcity of reliable time series of soil organic carbon monitoring data and often fail to replicate observed trends or appreciate any effects induced by changes in soil management.
This study quantifies C loss from contemporary soil management on specialist crop farms in the EU and the potential societal benefits from C sequestration potential and avoided C loss due to improved management. Our analysis is based on an evidence pool of 214 independent long-term time series of soil organic carbon measurements spanning a wide range of climatic conditions and soil types, and considers the implementation of reduced tillage, organic amendments, soil cover during winter, and crop rotations.
Overall, we estimate the potential for C sequestration from improved soil management on specialist crop farms, representing 40 % of all the arable land in the EU, to be 48 (±15) million tonnes CO2 equivalents yearly, which corresponds to 17 % (±8) of the target for additional carbon removals in the soil and forest sinks under the Fit for 55 package. In addition, our results show high spatial variability in C losses due to current soil management practices and potential C sequestration from improvements. The annual climate-change mitigation value per unit of land with improved management shows a four-fold variation across countries, with Finland exhibiting the highest value and Cyprus the lowest. This demonstrates that a C payment eco-scheme should be adjusted spatially to achieve cost-effective soil organic carbon sequestration in arable soils in the EU.