July 22nd 2014

Agricultural Impact on Water Quality 

Over the decades, farming nationwide has continued to develop and expand. According to the U.S. Environmental Protection Agency, more than 330 million acres of agricultural land in the United States now produces food and other products for the world. The state of Iowa alone produces 28 percent1 of U.S. pork and remains the nation’s No. 1 producer of corn and soybeans.  

As the industry grows, so does the use of fertilizers, pesticides, and other pollutants that can end up in lakes, rivers, and streams. Not only does this pollution threaten the water quality locally, but it also affects water sources across that nation as Iowa water flows through the Mississippi River and into the Gulf of Mexico.

Increased amounts of nutrients, sediment loads, fecal coliforms, and other agricultural runoff can damage aquatic ecosystems and public drinking water. In 2004, the National Water Quality Inventory2 reported agricultural pollution as the leading source of water impairment to rivers and streams.

Sources of this pollution include soil that washes off fields, chemical and natural fertilizer runoff, manure runoff from animal operations, and pesticides. Such pollutants can lead to clouded waterways and algae blooms, which cause decreased oxygen sources, killing fish and other aquatic plants. Such pollution also results in contaminated ground and drinking water.

Iowa’s Efforts to Improve Water Quality

As a national leader in agriculture, Iowa has made improving water quality a priority by executing new programs that promote conservation practices. In the past year, a voluntary water quality strategy was implemented in the state. The nutrient reduction strategy3 is offered to match farmers’ funds when he or she applies a water-quality improvement practice, such as planting ground cover. So far, the nutrient reduction strategy seems to be a success, and according to the Iowa Department of Agriculture, more than 1,000 Iowa farmers signed up4 for the cost-share funding in less than two weeks last fall.

Farmers also invested time to attend informational sessions, such as the workshops offered at the Iowa Power Farming Show in January, 2014. The show had 44 workshops that focused on utilizing cover crops. More than 1,000 farmers attended these workshops. Half of them reported they had never used cover crops before, but were interested in learning more.

Promising Future for Iowa Waterways

Recent studies of a few major rivers in Iowa indicated a declining trend5 for nitrates and phosphorus levels. For example, the Iowa Farm Bureau reported a decrease in nitrate concentration in the Raccoon River from 9 parts per million (ppm) in 2006 to 5 ppm in 2013. This fact was welcomed after the Raccoon River’s nitrate levels had increased to record levels last year after much rainfall.

While nutrient-laced waters leaving the state still exist, these decreasing nutrient concentrations levels are a win for the state’s nutrient reduction strategy and should be seen as encouragement to continue integrating conservation practices.

Recent Rainfall in Iowa

Although conservation practices have been put in place to decrease water pollution, recent rainfall in Iowa has caused fertilizer and manure to run off into local waterways. MMP360 enables producers to instantly run scenarios of compliant conservation practices that can continue to contribute to this downward trend of nitrate levels and better water quality in Iowa.


1. Iowa Farm Bureau. "Ag Facts." 2014. Web. 21 July 2014. <http://www.iowafarmbureau.com/public/167/ag-in-your-life/ag-facts>.

2. United States Environmental Protection Agency. The National Water Quality Inventory: Report to Congress for the 2004 Reporting Cycle – A Profile. By United States Environmental Protection Agency Office Of Water. Jan. 2009. Web. 20 June 2014. <http://water.epa.gov/lawsregs/guidance/cwa/305b/upload/2009_01_22_305b_2004report_factsheet2004305b.pdf>.

3. Iowa State University. "Iowa Nutrient Reduction Strategy." Web. 20 June 2014. <www.nutrientstrategy.iastate.edu>.

4. Northey, Bill. "Farmers Engaged in Iowa Water Quality Initiative.” Iowa Department of Agriculture, 11 Apr. 2014. Web. 21 June 2014. <http://www.iowaagriculture.gov/press/2014press/press04112014.asp>.

5. Love, Orlan. "Nutrient Levels Falling in Some Iowa Rivers." The Gazette. The Gazette (Eastern Iowa)22, 22 July 2014. Web. 21 June 2014. <http://thegazette.com/2014/03/09/nutrient-levels-falling-in-some-iowa-rivers-2/#ixzz2yPJJhDoV>.