Wilson, Grace Linnea2012-02-272012-02-272012-01https://hdl.handle.net/11299/121175University of Minnesota M.S. thesis. January 2012. Major: Applied plant sciences. Advisor:Paul Porter. 1 computer file (PDF); vi, 99 pages, appendices A-C.Cropping systems that incorporate perennial vegetation have been shown to improve water quality compared to annual cropping systems. The goal of this study was to evaluate the effect of perennial forage-based cattle production systems on land-use and water quality in Southeastern Minnesota. A scenario was developed where a fraction of the land area currently used for corn and soybean production was changed into use for pasture and hay. The area of land needed for pasture and hay production was assumed to equal that needed to feed the number of cattle necessary to provide for current consumer demand for beef in Southeast Minnesota. The soil and water assessment tool (SWAT) was used to evaluate the effects of this alternative, increased grazing scenario on water quality in a representative watershed within Southeast Minnesota, the South Branch of the Root River. Three different approaches were used for determining the location of the grazing lands within the watershed: targeting areas of high slope, targeting areas of low crop productivity values, and randomly distributed. The results of the study show that to provide enough beef to meet demand for Southeast Minnesota, a minimal change in land-use is needed; only 2.6% of the total land area of the region would be needed for use perennial forage and pasture. When placed on annual cropland areas with high slope, this 2.6% change in land area into perennial forage showed reductions in sediment and phosphorus field losses up to 13% and 10%, respectively. These results indicate that when strategically placed, altering land-use from annual cropping systems to perennial forage systems could result in notable improvements in water quality.en-USApplied plant sciencesThesis or Dissertation