Soil Organic Carbon Significantly Increases When Perennial Biomass Plantations Are Reverted Back to Annual Arable Crops

The cultivation of perennial biomass crops (PBCs) on marginal lands is necessary to provide feedstock for the bio-based EU economy and accrue environmental benefits through carbon (C) sequestration in soil. Short rotation coppice (SRC) species, e.g., willow, black locust, poplar, rhizomatous grasses, miscanthus, switchgrass, giant reed, have been tested many projects last 10 years investigate their productive potential contribution mitigation climate change. A major knowledge gap regarding PBCs fate accumulated soil organic (SOC), once PBC plantations are reverted arable crops. In this study, effects reversion SOC carbon-dioxide emission (CO2) were monitored over a 2-year period long-term (11-year) multispecies trial six PBCs: Three SRC species including poplar (Populus spp.), willow (Salix locust (Robinia pseudoacacia), three herbaceous grasses miscanthus (Miscanthus x giganteus), switchgrass (Panicum virgatum), reed (Arundo donax). change GHG emissions then modeled with ECOSSE model. Two after reversion, increased significantly all no significant difference between them. During phase, 5.35 Mg ha−1 was sequestered while 10.95 added by which indicated that 67% occurred reversion. model successfully used simulate trajectories (R2 = 0.77) CO2 from 0.82) PBCs. This high rate due humification belowground (roots + rhizomes/stumps), had mulched incorporated into layer (0–30 cm). first 2 months (on average 5.47 y−1) year (1.3–1.8 y−1). Considering entire cycle (13 reversion), showed annual rates higher than 1 y−1, placing as one most promising agricultural practices combine production, recovery production increasing SOC.