TITLE:
Modeling Water Quality Impacts of Growing Corn, Switchgrass, and Miscanthus on Marginal Soils
AUTHORS:
Mark A. Thomas, Laurent M. Ahiablame, Bernard A. Engel, Indrajeet Chaubey
KEYWORDS:
Water Quality Modeling, Perennial Grass, Runoff, Biofuels, Marginal Lands, GLEAMS-NAPRA
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.6 No.14,
October
31,
2014
ABSTRACT: The goal
of the study was to model water quality impacts of growing perennial grasses on
marginal soils. The GLEAMS-NAPRA and RUSLE models were used to simulate
long-term surface runoff, percolation, erosion, total phosphorus (TP), and
nitrate (NO3-N) losses associated with the production of corn-based
bioenergy systems (i.e. conventional
tillage corn and corn grain plus stover removal), switchgrass and Miscanthus on three marginal quality
soils and one good quality soil in Indiana. Simulations showed that switchgrass
and Miscanthus had no effect on
annual runoff, but decreased percolation by at least 17%. Results also
suggested a potential for reduction in erosion for Miscanthus across the soil types examined when compared to
corn-based bioenergy production. The production of switchgrass and Miscanthus did not have significant
effects on the simulated TP and NO3-N losses in runoff compared to
corn production systems. Nitrates leached from fertilized Miscanthus production were approximately 90% lower than NO3-N
leached from the production of fertilized switchgrass and corn systems.
Additional studies are needed to better understand the hydrology, erosion and
nutrient responses of Miscanthus and
switchgrass production to meet bioenergy demands.