Is switchgrass good for carbon savings? Long-term results in marginal land Running title: Switchgrass SOC storage capacity in marginal land Walter Zegada-Lizarazu 1, Federica Zanetti 1, Nicola Di Virgilio 2, Andrea Monti 1 1Department of Agricultural and Food Sciences, University of Bologna, Viale G. Fanin 44 – 40127, Bologna, Italy; 2CNR, Institute for the BioEcononomy, National Research Council of Italy, Via P Gobetti 101, I-40129 Bologna, Italy

Growing switchgrass in marginal land can be a valuable option to mitigate the risk of agricultural land abandonment whilst storing a significant amount of soil C. It was found a significant increase in SOC in a 13-years period. A significant positive correlation was observed between the C derived from switchgrass and SOC gain (the estimated switchgrass derived C was 12.7 Mg C ha^-1). The increased SOC along the field, however, was patchy, with the highest increments registered in the center of the field, while the lowest ones in the top and bottom of the hill.