The Effects of Increased Fertilizer Use on Nitrate Pollution in the Mississippi Watershed

Abstract

Reduction of nitrate pollution in the Mississippi Watershed is essential to improving water quality and reducing the formation of hypoxic zones (also known as a dead zones) in the Gulf of Mexico. Further concern about nitrate pollution has been caused by the speculation that increased global food demand will bring about an increase in fertilizer use per hectare. This research seeks to examine a typical creek in southeastern Iowa called Clear Creek. By measuring the nitrate levels in this creek, the amount of nitrate leached throughout the Clear Creek Watershed can be estimated. From this data, it is also possible to investigate the effect that increasing fertilizer application will have on nitrate pollution. This prediction gives a worst–case-scenario of what could happen if farming practices are not altered in a way that will decrease the leaching of nitrates from fertilized soil to waterways. Preliminary results indicate that a ten percent increase in fertilizer application could result in an additional 3,600 kilograms of nitrate in the Clear Creek Watershed during a single summer month.