Carbon footprint of four bioethanol cropping systems in a temperate region. (Research Article).

ABSTRACT.- Under the EU Renewable Energy Directive (2009/28/EC), estimating biofuel GHG emissions is essential to gauge emissions reductions compared to fossil fuels. Within this framework, the carbon footprint (CF) was calculated for four bioethanol cropping systems:a maize-wheat-sorghum rotation without the harvest of crop residues (MWS), a maize-wheat-sorghum rotation with harvested crop residues (MWS-R), switchgrass (Sw), and continuous sweet sorghum (Ss). The estimation followed a life-cycle analysis strategy. The CF varied between 0.04 and 3.68 kg CO2-eq l -1 ethanol.