TY - JOUR
T1 - Evaluation of selected watershed characteristics to identify best management practices to reduce Nebraskan nitrate loads from Nebraska to the Mississippi/Atchafalaya River basin
AU - Mittelstet, Aaron R.
AU - Gilmore, Troy E.
AU - Messer, Tiffany
AU - Rudnick, Daran R.
AU - Heatherly, Thomas
N1 - Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/5/1
Y1 - 2019/5/1
N2 - Nebraskan streams contribute excess nitrogen to the Mississippi/Atchafalaya River Basin and Gulf of Mexico, which results in major water-quality impairments. Reducing the amount of nitrogen (N) exported in these streams requires the use of best management practices (BMPs) within the landscape. However, proper BMP utilization has rarely been statistically connected to potential controls of N export within watersheds, particularly precipitation and soil characteristics. In this study, 19 watershed variables were evaluated in five categories (hydrological, physiographic, point sources, land use, and soil properties) to determine the characteristics that influenced variable nitrate nitrogen (NO 3 -N) concentrations in 17 Nebraska watersheds with known high NO 3 -N export rates. Each characteristic was derived from publicly-available datasets in an effort to develop a multiregional method. Of the 19 variables evaluated, 10 variables (developed, cropland, herbaceous, forest, excessively-drained soils, precipitation, base-flow index, slope, organic matter and point sources) were identified to statistically influence stream NO 3 -N concentrations. The 17 watersheds were divided into five subset groups using principal component analysis. Distributions of the 10 watershed variables were then used to determine the most applicable BMPs for NO 3 -N reductions for each stream subset: excessively drained with high baseflow index (Groups 1 and 2), dominantely row crop land usage with well-drained soils, higher precipitation, and an increased tendency for surface runoff concerns (Group 3), highly developed watersheds (Group 4), and single river dominated by wastewater treatment plant discharge (Group 5). Based on the most influential variables a variety of BMPs were recommended, including N fertilizer application management and accounting for N credit from mineralization and NO 3 -N in irrigation water (Groups 1 and 2), installation of riparian buffers and wetlands (Group 3), urban BMPs such as bioretention cells and permeable pavement (Group 4), and upgrades to the wastewater treatment plant (Group 5). This study provides an improved technique for facilitating watershed management by linking BMPs directly to the characteristics of each watershed to reduce current nitrate export.
AB - Nebraskan streams contribute excess nitrogen to the Mississippi/Atchafalaya River Basin and Gulf of Mexico, which results in major water-quality impairments. Reducing the amount of nitrogen (N) exported in these streams requires the use of best management practices (BMPs) within the landscape. However, proper BMP utilization has rarely been statistically connected to potential controls of N export within watersheds, particularly precipitation and soil characteristics. In this study, 19 watershed variables were evaluated in five categories (hydrological, physiographic, point sources, land use, and soil properties) to determine the characteristics that influenced variable nitrate nitrogen (NO 3 -N) concentrations in 17 Nebraska watersheds with known high NO 3 -N export rates. Each characteristic was derived from publicly-available datasets in an effort to develop a multiregional method. Of the 19 variables evaluated, 10 variables (developed, cropland, herbaceous, forest, excessively-drained soils, precipitation, base-flow index, slope, organic matter and point sources) were identified to statistically influence stream NO 3 -N concentrations. The 17 watersheds were divided into five subset groups using principal component analysis. Distributions of the 10 watershed variables were then used to determine the most applicable BMPs for NO 3 -N reductions for each stream subset: excessively drained with high baseflow index (Groups 1 and 2), dominantely row crop land usage with well-drained soils, higher precipitation, and an increased tendency for surface runoff concerns (Group 3), highly developed watersheds (Group 4), and single river dominated by wastewater treatment plant discharge (Group 5). Based on the most influential variables a variety of BMPs were recommended, including N fertilizer application management and accounting for N credit from mineralization and NO 3 -N in irrigation water (Groups 1 and 2), installation of riparian buffers and wetlands (Group 3), urban BMPs such as bioretention cells and permeable pavement (Group 4), and upgrades to the wastewater treatment plant (Group 5). This study provides an improved technique for facilitating watershed management by linking BMPs directly to the characteristics of each watershed to reduce current nitrate export.
KW - Leaching
KW - Nitrate-N
KW - Principle component analysis
KW - Surface water
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U2 - 10.1016/j.agee.2019.02.018
DO - 10.1016/j.agee.2019.02.018
M3 - Article
AN - SCOPUS:85062443782
SN - 0167-8809
VL - 277
SP - 1
EP - 10
JO - Agriculture, Ecosystems and Environment
JF - Agriculture, Ecosystems and Environment
ER -