
Principal Investigator: David J. Mulla, Professor, Department of Soil, Water, and Climate, University of Minnesota
USGS-WRRI 104B/ CAIWQ Competitive Grants Program
March 2005 - February 2006
The project hypothesized that water quality impairment is primarily driven by factors accounted for by agroecoregion boundaries, including major cropping system types, slope steepness, soil internal drainage, and mean annual precipitation. Within agroecoregion boundaries, at the scale of minor watersheds (watersheds encompassed by an 8-digit HUC), water quality impairment will vary primarily in response to the spatial variability in slope steepness, and density of animal units in feedlots. We hypothesize that the variability in water quality is greater for minor watersheds across different agroecoregions than for minor watersheds within agroecoregions.