title: At-grade stabilization structure impact on surface water quality of an agricultural watershed.
abstract: Decades of farming and fertilization of farm land in the unglaciated/Driftless Area (DA) of southwestern Wisconsin have resulted in the build-up of P and to some extent, N, in soils. This build-up, combined with steep topography and upper and lower elevation farming (tiered farming), exacerbates problems associated with runoff and nutrient transport in these landscapes. Use of an at-grade stabilization structure (AGSS) as an additional conservation practice to contour strip cropping and no-tillage, proved to be successful in reducing organic and sediment bound N and P within an agricultural watershed located in the DA. The research site was designed as a paired watershed study, in which monitoring stations were installed on the perennial streams draining both control and treatment watersheds. Linear mixed effects statistics were used to determine significant changes in nutrient concentrations before and after installation of an AGSS. Results indicate a significant reduction in storm event total P (TP) concentrations (P = 0.01) within the agricultural watershed after installation of the AGSS, but not total dissolved P (P = 0.23). This indicates that the reduction in P concentration is that of the particulate form. Storm event organic N concentrations were also significantly reduced (P = 0.03) after the AGSS was installed. We conclude that AGSS was successful in reducing the organic and sediment bound N and P concentrations in runoff waters thus reducing their delivery to nearby surface waters.
authors: Dep. of Land and Water Resources, Dane County WI, 5201 Fen Oak Dr., Madison, WI, 53718, USA.
authors: Kyle R
authors: KR
authors: Minks
authors: Department of Soil Science, University of Wisconsin-Madison, 1525 Observatory Drive, Madison, WI, 53706, USA. Electronic address: mdruark@wisc.edu.
authors: Matthew D
authors: MD
authors: Ruark
authors: Department of Soil Science, University of Wisconsin-Madison, 1525 Observatory Drive, Madison, WI, 53706, USA.
authors: Birl
authors: B
authors: Lowery
authors: Department of Soil Science, University of Wisconsin-Madison, 1525 Observatory Drive, Madison, WI, 53706, USA.
authors: Fred W
authors: FW
authors: Madison
authors: Discovery Farms, University of Wisconsin-Extension, 40195 Winsand Drive, Pigeon Falls, WI, 54760, USA.
authors: Dennis
authors: D
authors: Frame
authors: U.S. Geological Survey, Wisconsin Water Science Center, 8505 Research Way, Middleton, WI, 53562, USA.
authors: Todd D
authors: TD
authors: Stuntebeck
authors: U.S. Geological Survey, Wisconsin Water Science Center, 8505 Research Way, Middleton, WI, 53562, USA.
authors: Matthew J
authors: MJ
authors: Komiskey
authors: College of Natural Resources, University of Wisconsin-Stevens Point, Stevens Point, WI, 54481, USA.
authors: George J
authors: GJ
authors: Kraft
mesh_terms: D000383:Agriculture; D005618:Fresh Water / Q000032:analysis*; D009584:Nitrogen / Q000032:analysis*; D010758:Phosphorus / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014877:Water Pollution, Chemical / Q000517:prevention & control*; D060753:Water Quality; D014922:Wisconsin
chemical_list: D014874:Water Pollutants, Chemical; D010758:Phosphorus; D009584:Nitrogen
keywords: At-grade stabilization structure; Nitrogen; Phosphorus; Sediment basin; Storm runoff