Unintended consequences of biofuels production?The effects of large-scale crop conversion on water quality and quantity

Open-File Report 2010-1229
By: , and 



In the search for renewable fuel alternatives, biofuels have gained strong political momentum. In the last decade, extensive mandates, policies, and subsidies have been adopted to foster the development of a biofuels industry in the United States. The Biofuels Initiative in the Mississippi Delta resulted in a 47-percent decrease in cotton acreage with a concurrent 288-percent increase in corn acreage in 2007. Because corn uses 80 percent more water for irrigation than cotton, and more nitrogen fertilizer is recommended for corn cultivation than for cotton, this widespread shift in crop type has implications for water quantity and water quality in the Delta. Increased water use for corn is accelerating water-level declines in the Mississippi River Valley alluvial aquifer at a time when conservation is being encouraged because of concerns about sustainability of the groundwater resource. Results from a mathematical model calibrated to existing conditions in the Delta indicate that increased fertilizer application on corn also likely will increase the extent of nitrate-nitrogen movement into the alluvial aquifer. Preliminary estimates based on surface-water modeling results indicate that higher application rates of nitrogen increase the nitrogen exported from the Yazoo River Basin to the Mississippi River by about 7 percent. Thus, the shift from cotton to corn may further contribute to hypoxic (low dissolved oxygen) conditions in the Gulf of Mexico.

Study Area

Publication type Report
Publication Subtype USGS Numbered Series
Title Unintended consequences of biofuels production?The effects of large-scale crop conversion on water quality and quantity
Series title Open-File Report
Series number 2010-1229
DOI 10.3133/ofr20101229
Year Published 2010
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Mississippi Water Science Center
Description 6 p.
Larger Work Type Report
Larger Work Subtype USGS Numbered Series
Larger Work Title Welch, H.L., Green, C.T., and Coupe, R.H., 2009. The fate and transport of nitrate through the unsaturated zone at a site in northwestern Mississippi in Geological Society of America 2009 Annual Meeting, Proceedings: Geological Society of America Abstracts with Programs, volume 41, number 7, p. 29. Green, C.T., Welch, H., and Coupe, R., 2009. Multi-tracer analysis of vertical nitrate fluxes in the Mississippi River Valley alluvial aquifer, in Eos Transactions of the American Geophysical Union, 90 (52), Fall meeting, Abstract H31C-0799.
Country United States
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
Additional publication details