Overview: The process of developing the U.S. Department of Agriculture Feedstock Carbon Intensity Calculator (USDA FD-CIC) entailed two main steps. First, to estimate how climate-smart farming practices impact soil organic carbon and nitrous oxide emissions, scenarios were generated from two agrosystem models (DAYCENT and SALUS). In general, the models simulated the effect of climate-smart agriculture (CSA) practices on greenhouse gas (GHG) emissions over a thirty-year cropping period. The models simulated these effects regionally across the United States for a) various combinations of climate-smart farming practices, b) various crops within a rotation, and c) various rotations. Second, there was post-processing of the output from DAYCENT and SALUS to a) apportion the GHG emissions within and across rotations to specific feedstocks and b) develop a method for determining the carbon intensity of biofuels that source climate-smart feedstocks. There was additional post-processing undertaken (not using output from DAYCENT or SALUS) to determine how climate-smart farming practices would impact on-farm fuel use and upstream GHG emissions from fertilizer production. This white paper focuses on the second of these two steps.
