Minnesota River Assessment Project Level II Land Use Analysis

Level II of the MRAP land use study focused on sediment and nutrients as primary pollutants. This was accomplished through the use if computer simulation models. Through this process it was determined that approximately 200,000 tons of soil per year are eroding from the 64,100 total acres of cropland. About 19% of his sediment makes it into the mainstem of the Minnesota River. The majority of the acreage was eroding as or below what is considered the tolerable level of 5 tons per acre per year. From the information gathered three alternatives were modeled. The most successful of these alternatives was the use of only conservation tillage. It was also determined that higher residue reduces runoff and erosion. Residue preservation along with spring application of fertilizers would reduce both soil and nutrient loss.