Article
Impact of Lane Use Change Due to Bioenergy on Midwestern US Hydrology
Bioenergy and Water
(2013)
Abstract
The objective of this paper is to analyze and discuss the impact of land use change due to
bioenergy on Midwestern US hydrology. Together, soybean and maize form the largest single
ecosystem type of the contiguous United States. This agro-ecosystem represents the largest single
land-use in the Midwestern US and dominates regional ecosystem services such as food
production, water quality, evaporation of water to the atmosphere, nutrient cycling, carbon
sequestration, as well as other services. In addition to being two of the dominant food crops
grown throughout the US and the world, these two crops represent the dominant feedstocks used
for bioenergy production in the US with close to 40% of the total corn harvested in the US being
used specifically for grain ethanol production. The recent increase in the percentage of harvested
corn dedicated to ethanol production is coupled with an increase in total area of land planted in
corn.
Biophysically-based land surface models provide an opportunity to investigate the consequences
of land use change over longer time scales and over larger spatial scales. For example, one such
model was used to evaluate changes in Midwest U.S. hydrology resulting from large-scale
conversion from the existing land cover to one that contains miscanthus and one that contains
switchgrass. The new algorithms for miscanthus and switchgrass were created through
integration of an existing grass algorithm with crop management modules. These algorithms were
calibrated by adjusting model parameters based on observations of miscanthus and switchgrass at
the University of Illinois south farms and at a number of locations in Illinois. Regional
simulations with the current land cover, miscanthus and switchgrass land cover scenarios were
conducted to examine the impact of large-scale perennial grass production on the hydrologic
cycle.
Land use change to accommodate production of miscanthus and switchgrass are likely to
influence more than the quantity of water flowing through vegetation and other major
components of the hydrologic cycle. Current agricultural practices result in large amounts of
nitrogen fertilizer leaching out of maize/soybean fields through subsurface runoff (drainage)
which reaches the Gulf of Mexico causing an area over 10000 km2
of hypoxic conditions. Since
perennial grasses require less fertilizer than maize, the potential exists for cellulosic feedstock
production to decrease the leaching of nitrogen into the water improving water quality.
Alternatively, if the hydrologic cycle is perturbed by an increase in rates of ET, less water
flowing though streams and rivers could potentially be more concentrated in pollutants, thereby
degrading water quality. In either case, large-scale changes in ET and nutrient application
compared to existing land cover has the potential to alter the flux of nitrate through the
Mississippi River Basin to the Gulf of Mexico.
Keywords
- Evapotranspiration,
- water use efficiency,
- surface hydrology,
- climate
Disciplines
Publication Date
2013
Publisher Statement
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.
Citation Information
Carl J. Bernacchi, Andy VanLoocke and Stephen W. Nesbitt. "Impact of Lane Use Change Due to Bioenergy on Midwestern US Hydrology" Bioenergy and Water (2013) Available at: http://works.bepress.com/andy_vanloocke/14/