Sequestration potential of energy crop Miscanthus x giganteus cultivated in continental part of Croatia

Miscanthus x giganteus is an energy crop relatively recently introduced into Croatia, that is suitable for cultivation on marginal or abandoned agriculturl land. Energy crops can contribute to climate change mitigation both by carbon sequestration into soil/plant pool and by substitution of fossil fuels. Therefore, the aim of this paper is to evaluate the impact of Miscanthus x giganteus cultivation on the environment by determination of soil and soil-plant system's carbon budget, as well as to estimate the sequestration potential of Miscanthus stand on abandoned agricultural land at national level. After the 3 years of Miscanthus cultivation, soil pH and K2O decreased, P2O5 increased and N-tot remained the same. Plant biomass increased from April, peaked in September, and decreased towards the spring harvest with harvested yield of 14.5 t/ha. Average soil respiration amounted 9.1 t/ha/y, and didn't show seasonal trend, or significant correlation to soil temperature and moisture. Estimated sequestration potentials of Miscanthus are 1.3 (soil system) and 2.0 (soil-plant system) t/ha/y. The highest contribution to carbon gains and losses had respectively preharvest losses and soil respiration. Between 704 520-3 251 600 t C could be sequestrated in soil/plant pool in Miscanthus lifespan if 5-15% of abandoned agricultural land would be converted to Miscanthus cultivation. Therefore, Miscanthus represents biological carbon sink due to great sequestration potential and additional fossil fuel replacement benefits.