BY

Biofuels have a great potential to alleviate our dependence on non-renewable fossil fuel products; however the beneficial effects of substituting biomass for fossil fuel is reduced if the biofuel crops also emit large amounts of greenhouse gases (GHGs), such as carbon dioxide (CO2) and nitrous oxide (N2O) during their production. Most crops require nitrogen (N) fertilization to maximize productivity, but the amount of N fertilizer Miscanthus x giganteus might need is currently not known. Because M. x giganteus is highly efficient in its N use, it is a great potential energy crop because it has had large yields even at low N inputs from fertilizers (including no additions of N fertilizer). Therefore, it is critical to determine the response of M. x giganteus to N fertilizer rates and determine the effect of fertilization on GHG emissions. The main objective of this study was to examine the effect of N fertilization rates (0, 60 and 120 kg N ha-1 of urea) on GHG emissions from production of M. x giganteus on a central Illinois Mollisol. The study had twelve, 10x10 m plots organized in four replicate rows with each of the three N fertilizer treatments placed randomly in each row. Gas samples to determine N2O and CO2 fluxes were taken near noon throughout the year (March-November) when soil temperatures were warm enough to support microbial activity. In addition, soil moisture and soil temperature wer