The quality of our surface waters is important to human, ecological, and economic health in our state. Certain agricultural practices can degrade surface waters by contributing excess amounts of sediment and phosphorus. If we wish to maintain or improve the quality of surface waters in the state of Wisconsin, or elsewhere, we need to find out how much sediment and phosphorus (P) is being lost by farm fields (a large fraction of the land use in Wisconsin) and the effectiveness of conservation techniques to reduce these losses.

Erosion research in the past has focused mainly on studies on small uniform plots. While this research has been very informative, it is difficult to scale up to entire fields, where topography and soil conditions are not uniform. The research described below is part of two related studies that seek to address the scaling up issue.