370-2 Climate Impacts on Nitrogen Loads in Rivers of the Upper Midwest.
Kari Wolf – University of Minnesota
1991 Upper Buford Circle St. Paul, MN 55108
Satish Gupta – University of Minnesota, St. Paul, MN 55108
Excess nitrogen in rivers of the Midwestern United States has been linked to the hypoxic condition in the Gulf of Mexico. Much of the nitrogen in these rivers is from agricultural landscapes through tile drainage. In recent years, there has also been 10-15% increase in precipitation in the upper Midwestern United States. This study evaluated the impact of increased precipitation on nitrogen loads in various rivers of the upper Midwestern United States. The river included the Minnesota River at Jordan, the Raccoon and the Des Moines Rivers at Des Moines, IA. The results showed that much of the increase in N loads in these rivers is due to increased precipitation not only in the current year but also in the previous year. Five year moving average trends of N loads vs. precipitation showed that the relationship of N loads to precipitation has not changed much since 1970s. In this presentation, we also discuss the role of warming temperatures in recent years on possible increased N loads in these rivers.