The study delivers values on greenhouse gas (GHG)-emission via cultivation of silage maize and sugar
beet and of GHG-saving potential of electricity produced from biogas out of both biomass crops. Data
are based on three rainfed crop rotation field trials in Germany (2011–2014) representative for Central
Europe and can serve as default values. It was found that GHG-emission via crop cultivation was driven
mainly by nitrous oxide emission from soil and mineral N-fertilizer use and was 2575–3390 kg carbon
dioxide equivalents (CO2eq) per hectare for silage maize and 2551–2852 kg CO2eq ha1 for sugar beet
(without biogas digestate application). Integrating a GHG-credit for surplus N in the biogas digestate
reduced total GHG-emission via crop cultivation to 65–69% for silage maize but only to 84–97% for sugar
beet. The GHG-saving potential of electricity production from biogas was calculated for three biogas
plants differing in technical characteristics. The GHG-saving potentials were generally >70% (silage
maize: 78–80%, sugar beet: 72–76%) and the authors concluded that the technical setting of the biogas
plant had a slight impact only. Overall, the authors assumed that the major potential for GHGemission’s
reduction along the bioenergy production chain were N-management during crop cultivation
and methane losses at the biogas plant. Finally, sugar beet, if cultivated in crop rotation, was shown to be
an efficient alternative to silage maize as a biomass crop in order to achieve a higher diversity in biomass
crop cultivation.