Does carinata, an oilseed crop for sustainable aviation fuel, improve the eco-efficiency of crop rotations in South Georgia, United States?

Abstract

In 2019, the aviation sector emitted about five percent of the total energy-related carbon dioxide equivalent (CO2e) emissions in the United States. The replacement of conventional aviation fuel with drop-in sustainable aviation fuel (SAF) derived from various biomass-based feedstocks is vital to reduce the overall CO2e emissions of the aviation sector. The SAF derived from Brassica carinata (carinata), an oilseed winter crop, could help the aviation sector mitigate CO2e emissions. Therefore, it is vital to develop a framework for assessing the eco-effectiveness of carinata in crop rotations by combining economic and environmental benefits. We identified 292 crop rotations (over a four-year rotation period with and without carinata) in South Georgia, the southern region of a major agricultural state located in the Southern United States. We conducted a comprehensive life cycle assessment to determine the total carbon emissions of selected crop rotations. We combined the carbon emissions and profitability information using data envelopment analysis (DEA) to estimate the eco-efficiency score of each crop rotation. The results indicate that crop rotations with carinata emit less CO2e than crop rotations without it, especially when carinata replaces winter wheat. Carinata's profitability (net present value of $2996/acre) is highest in a “corn-corn-soybean” rotation at a contract price of $441 per metric ton. Finally, “cotton-carinata-cotton-fallow-soybean-fallow-cotton-carinata” is the most eco-efficient rotation at the same contract price. Overall, carinata increases eco-efficiency at the farm level and, thereby, has the potential to promote the bioeconomy in South Georgia and beyond.