Iowa Corn Production and its Impact on The Dead Zone in the Gulf of Mexico

Schimmel/Conrades Science Center Atrium

Agricultural runoff from corn farms in Iowa is believed to contribute to the growing dead zone in the Gulf of Mexico (Beman et al., 2005; Minnesota Center for Environmental Advocacy, 2016). This natural, but mostly human induced phenomenon (Simmon, 2012), also termed a hypoxic (low oxygen) zone, is partially driven by an increase in the demand for food and biofuel production, prompting farmers to have a heavier reliance on phosphorus- and nitrogen-rich fertilizers. Loose topsoil containing these phosphorus and nitrogen-rich fertilizers are transported into streams during heavy rainfall events, travelling through the Mississippi River system and emptying into the Gulf of Mexico. The excess nutrient loading creates massive algae blooms and subsequent hypoxic conditions. The growing number of hypoxic zone events contributes to the range of this dead zone, spanning 5,052 square miles as of August 1, 2014 (Simmon, 2012). These events contribute to massive fish kills which threatens fisheries and a large human food source (Altieri & Gedan, 2015; Bruckner, 2012). Analysis of this urgent manmade problem relates trends in Iowa corn production to the increasing dead zone conditions in the Gulf of Mexico during 2010- 2015. To mitigate these effects, this work seeks to better understand our current farming practices and to assess alternative techniques that are believed to be less impactful on the hydrologic environment.