A regional assessment of land, irrigation water, and greenhouse gas emissions from canola biodiesel feedstock production in California

Abstract. The objective of this research is to evaluate the effects of cropping choices on land, water use for irrigation, and greenhouse gas emissions after introducing canola (Brassica napus L.) cultivation for the production of 60 million gallons of biodiesel per year. Characterization of regional farm-level cropping patterns and agronomic inputs and economic data are used to model the adoption of canola in place of the diverse incumbent cropping patterns in four regions of California: Northern and Southern San Joaquin Valleys, Sacramento Valley, and Southern California, using the Bioenergy Crop Adoption Model. The life cycle assessment approach is then used to assess environmental impacts due to cultivation of canola in place of the incumbent cropping patterns in terms of: (1) land use; (2) life-cycle greenhouse gas emissions due to direct land use change (kg CO₂e ac^-1); (3) greenhouse gas emissions due to irrigation water (kg CO₂e ac^-1); and (4) life-cycle greenhouse gas emissions expressed in grams of carbon dioxide equivalent per megajoule of biodiesel. Preliminary results show the adoption price of the canola with a yield of 1.5 U.S. tons per acre is estimated to be $481 per ton of canola in 2012 dollars at which point a total of 508,400 acres appear in canola cultivation. This land area (508, 400 acres) is equivalent to approximately 89 million gallons of biodiesel from canola per year given the assumptions stated in this study. Consequentially, crops that are less profitable are replaced with canola and greenhouse gas emissions due to irrigation water are reduced while maintaining a diversified percentage of the incumbent cropping patterns, as well as canola cultivation.