Impact of Cellulosic Biofuel Production

Jamie Smedsmo, University of North Carolina

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Increased production of biofuels is included in a national strategy striving for energy independence in the United States. As part of that strategy, the Energy Independence and Security Act of 2007 requires that 16 billion gallons per year of cellulosic biofuel be included in transportation fuels by 2022. To meet this goal, a large-scale land-use shift from feedstock to cellulosic crop production is expected. These cellulosic bioenergy crops, such as switchgrass, are typically deep-rooted perennial crops. These perennial crops have very different water, fertilizer, and herbicide requirements than shallow-rooted annual row crops, such as corn, soy and wheat, that currently dominate agricultural landscapes. The impact of this row crop production on water quality has been widely recognized; a switch to perennial crops would be expected to improve water quality when heavily fertilized and tilled row crops are displaced. This research assesses sustainability and risk associated with a shift in agricultural production to cellulosic biofuel crops within the context of a changing climate. The Soil and Water Assessment Tool (SWAT) model was implemented for the Arkansas-White-Red River Basin, an area in which cellulosic biofuel production is economically feasible. Model runs include climate change scenarios with longer and more severe droughts and more severe storms. Using results from this model, we quantify tradeoffs between crop yield and water quality, including uncertainties in those estimates, to understand spatial variation in risks.

Abstract Author(s): Jamie Smedsmo, Henrietta Jager, and Latha Baskaran