In this article, we applied the Denitrification-Decomposition (DNDC) model to field trials using miscanthus plants grown on heavy and medium heavy soils in Poland. The DNDC model was calibrated and then validated against experimental data. Similar results were found between the simulated and measured values of yield. The difference between the simulated and measured values of yield was from 1.20 to 3.09 t ha(-1) yr(-1) and the RMSE was very low (1.67). Furthermore, the RRMSE was equal to 10.30%, which confirms the high accuracy of the predicted results. The calibrated model was used to simulate yield, as well as simulating the greenhouse gas (GHG) emissions (CO2, CH4, N2O) for miscanthus cultivation in Poland.