TITLE:
Quantifying Hydrologic and Water Quality Responses to Bioenergy Crops in Town Creek Watershed in Mississippi
AUTHORS:
Prem B. Parajuli, Sarah E. Duffy
KEYWORDS:
Perennial Grass; Water Quality; Watershed; SWAT
JOURNAL NAME:
Journal of Sustainable Bioenergy Systems,
Vol.3 No.3,
September
13,
2013
ABSTRACT:
Bioenergy crops are considered as a feedstock source,
which can be grown in marginal soils. However, these crops may have different
levels of crop yield potential and environmental benefits. The objectives of
this study were to model and compare the effects of four bioenergy crops (corn—Zea mays, soybean—Glycine max (L.) Merr.,
miscanthus—Miscanthus-giganteus,
and switchgrass—Panicum virgatum) in
the Town Creek watershed (TCW) in northeast Mississippi using the Soil and
Water Assessment Tool (SWAT) model. The calibrated SWAT model for TCW was used
to quantify impacts to streamflow, crop yield, and sediment yield. The SWAT
model reasonably (3·s-1) from the TCW when
compared with the USGS observed stream flow (29.34 m3·s-1.
In addition, model reasonably predicted (±6%) average annual corn yield (4.66
Mg·ha-1) and soybean yield (1.42 Mg·ha-1) as compared to
National Agricultural Statistics Service (NASS) reported average annual corn
(4.96 Mg·ha-1) and soybean yield (1.34 Mg·ha-1) from the
watershed. Further, the model simulated results from this study determined that
long-term average annual feedstock yield from TCW is the greatest when growing
miscanthus grass (817,732 Mg) followed by switchgrass (477,317 Mg), corn
(236,132 Mg), and soybeans (65,235 Mg). The SWAT model predicted the greatest
annual average sediment yield (6.62 Mg·ha-1) from continuous corn
crop scenario while the perennial grasses (switchgrass and miscanthus) had the
lowest sediment yield (2.91 Mg·ha-1 and 3.20 Mg·ha-1 respectively). Overall, producing a perennial grass in the TCW would provide
the largest biomass feedstock source with the least environmental impact. The
results of this study will help to