ARS | Publication request: Effect of shifting crop production for biofuel demand on soil and water quality

Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: March 23, 2011
Publication Date: April 27, 2011
Citation: Beeson, P.C., Sadeghi, A.M., Daughtry, C.S., Tomer, M.D., Arnold, J.G. 2011. Effect of shifting crop production for biofuel demand on soil and water quality [abstract]. Abs. 4, BARC Poster Day.

Technical Abstract: The effect of shifting cropping systems to dominantly corn for biofuels, in particular ethanol production, could have serious implications on soil and water quality. Proper land management for biofuels production in agriculture is critical to achieve because of maintaining the sustainability of land resources. The South Fork of the Iowa River, for example, covers about 780 square-kilometers (193,000 ac) and is one of 15 benchmark watersheds of the USDA Conservation Effects Assessment Project (CEAP). The South Fork is historically 80-86% agricultural land with mainly either corn or soybean cultivation. In 2000, the watershed was 44% corn and 41% soybean, since then the disparity has grown and the maximum difference is seen in 2007 when the watershed was 59% corn and 21% soybean. We are using a watershed and field process-based water quality model to track changes in soil and water quality due to the increased fertilizer application and field operations resulting from the shift from corn-soybean rotation to continuous corn. The average annual nitrate load trends upward, with a maximum difference of 125% (2005 to 2007); however, this increase also corresponds to a large increase in annual rainfall. Furthermore, some agricultural areas could see a switch to strictly corn production in order to meet federal ethanol production goals. This scenario was also simulated to show the impacts to soil and water quality from large-scale expansion of corn cultivation.