Study: Greenhouse Gas Balance Of Different Energy Cropping Systems

In a recent open-access study published in Ecological Applications, Paul Adler from the USDA's Agricultural Research Service (ARS) and colleagues compare the net production of carbon dioxide and two other greenhouse gases (GHG) associated with producing biofuels via different pathways from several bioenergy crops. Since a GHG balance includes the emissions from energy used during farming, transporting and converting the biomass into biofuels, the study also offers an energy balance of the different biofuels.

The results of the life-cycle analysis show that of all bioenergy pathways studied, the gasification of hybrid poplar and switchgrass for the production of electricity reduced GHG emissions most. A conventional-till corn–soybean–alfalfa rotation the biomass of which is converted into ethanol had the smallest potential. If the biofuels replace gasoline and diesel, the resulting reduction of GHG emissions for corn rotations was 50–65%, for reed canarygrass 120%, and about 145% and 165% for switchgrass and hybrid poplar, respectively.

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