The legacy effect of long-term management on greenhouse-gas fluxes in European croplands.

In the frame of climate change mitigation, the effect of agricultural practices on soil organic carbon (SOC) stocks has been widely studied in different pedoclimatic conditions across Europe. Practices that have been identified as generally having a positive effect on SOC stocks include those increasing carbon inputs to the soil via external organic matter or via incorporation of crop residues. These practices also modify the soil N2O and CH4 fluxes; this is highly relevant for estimating the overall effect of management strategies on the soil greenhouse gas (GHG) balance, but so far, this aspect has not been assessed comprehensively. In this work, we make use of long-term experiments covering a large range of soil and environmental conditions in Europe. Further, the experiments were selected based on the management practices under investigation (addition of organic matter, crop residue management) and access to data on SOC stock changes as affected by management. Undisturbed soil samples were investigated for non-CO2 fluxes under controlled conditions. As research within the scope of global change, soils underwent a drying-and-rewetting cycle to study the soil response to extreme events in relation to the organic matter inputs. Our lab data provide relevant information on soil non-CO2 fluxes, which will be integrated with SOC stock change data, field GHG flux data and ancillary soil information. Overall, we will increase our understanding of soil processes towards identifying and promoting win-win scenarios between greenhouse gas fluxes and soil carbon storage in European croplands.