Phosphorus runoff to Clear Creek

Phosphorus is a nutrient crucial to row crop production, but phosphorus runoff from fields to nearby surface waters is a persistent problem that threatens the quality of rivers and streams. This is especially true for Iowa with its abundance of agricultural practices. In order to better understand the phosphorus dynamics of a watershed with agricultural land use, Clear Creek in Iowa was studied. Total, dissolved, and suspended reactive phosphorus concentrations were measured and mass fluxes were calculated. Through this research it was determined that most of the mass of phosphorus in Clear Creek is transferred during high flow events and is attached to solids. The headwaters area of this stream was found to be a major source of phosphorus due to the abundance of row crops and steeply sloped land.