Nitrogen fertilization practices have a significant effect on the LCA results of biodiesel chains, which warrants reliable inventory data. In this study focused on the Lorraine region (eastern France), we established a typology of oilseed rape fields based on fertilization practices, and used the agro-ecosystem model CERES-EGC in lieu of generic emission factors to simulate the productivity and externalities associated with oilseed farming. The results were subsequently used to generate an LCA of biodiesel from oilseed rape. We also tested the effect of improved practices on the LCA results. In Lorraine, oilseed rape crops appeared to be frequently over fertilized compared to best management practices. Switching to improved practices with optimal fertilization has a potential to reduce the GWP of 1 megajoule of biodiesel by around 6 gr CO 2eq, against a total life-cycle of 43.9 gr CO 2eq.
