The study compared the field N2O emissions for the four corn cropping systems for the production of bioethanol estimated by the IPCC methodology and simulated by DNDC model. The obtained results were used to estimate the agricultural greenhouse emissions. Agricultural emission estimations were made using the calculator BioGrace v. 4 public, which has been recognized by the European Commission as the official tool for calculating greenhouse gas emissions in accordance with the requirements of Directive 2009/28/EC. The application of field emissions estimated by the IPCC methodology ensure GHG emissions reduction ? 50% in 12 provinces. Introduction of a N2O field emission simulated by DNDC model to the calculation can extend the resource base of Wielkopolskie and Zachodniopomorskie.