Twenty years of conservation effects assessment in the St. Joseph River watershed, Indiana

Lake Erie has a long and storied his-tory with water quality impairment and conservation. Following the pass-ing of the Clean Water Act in the 1970s, total phosphorus (P) loading to the lake substantially decreased through permitting of point sources and through conserva-tion efforts to decrease sediment loss from agricultural fields. While total P losses to Lake Erie have remained relatively stable since the 1990s, dissolved P has increased and resulted in increases in the extent and severity of algal blooms over the past two decades (Smith et al. 2015b). Both agricultural industry and environmen-tal quality are vital to local and regional economies. To achieve a balance between these important resources, there is a criti-cal need to better understand the effect of agricultural practices on crop production and water quality in the national priority Lake Erie watershed.