Land management at the major watershed - Agroecoregion intersection

The watershed natural resources management framework is prevalent today bec ause land use in watershed is presumed to be reflected in receiving stream water quality. However, landscape characteristics affecting soil erosion an d water quality (e.g., precipitation, geomorphology, slope, soil internal d rainage, cropping system) often vary significantly within a single large wa tershed (> 200,000 ha). A uniform watershed best management practice would not account for this variability and would not be satisfactory for soil con servation water quality, or socioeconomic returns. It is highly unlikely th at stream water quality monitoring will take place on enough small streams within a large watershed to capture the landscape variation. We have develo ped "agroecoregions" to quantify this variation, bared on empirical data fr om the Minnesota River Basin (MRB). This approach is needed to help target cleanup efforts to the most sensitive soils and landscapes within the most critical watershed. Our work shows that soil erodibility index variability and stream biotic habitat scores were better represented by agroecoregions than by watershed. Stakeholder characterization and economic analysis revea l a large variance in attitudes and beliefs about pollution issues and miti gation costs in the MRB, due in part to problems of scale perception (e.g., entire basin, major watershed, county city, farm). We suggest that watersh ed management in highly agricultural watershed will be most effective when hydrologic watershed are used as a framework that is complemented by agroec oregions to identify and target regions where specific combinations of best management practices for agricultural sediment and phosphorus abatement ar e most appropriate.