Toward Progress on Nutrient Reduction

Kristin Peterson
Newsletter Issue: 
April 2015

Researchers out in rows of crops
Above: University researchers test cover crops, shown to improve soil
quality and reduce nutrient run-off.

Cropland in the United States is a vital part of the economy. Cropland provides the U.S. with food, fuel, fiber and other materials. But, with croplands comes an added environmental risk. Farm nutrients, animal manure and fertilizers like phosphorus and nitrogen can seep into waterways causing pollution. The consequences of nutrient pollution are particularly evident where the Mississippi River enters the Gulf of Mexico. There, a dangerous hypoxic (low oxygen) zone threatens fish, shrimp and other marine animals.

Nutrient management plans have the potential to help reduce environmental impact while making nutrient use more efficient for the farmer.

 In 2011 EPA issued a nationwide directive, “Working in Partnership with States to Address Phosphorus and Nitrogen Pollution through Use of a Framework for State Nutrient Reductions.” The agency asked states to develop state nutrient management plans that accelerate nutrient reduction efforts.

This national effort put out by the EPA to all 50 states has received a response from much of the United States.

“We’re very excited about the groundwork underway,” said Ellen Gilinsky, Senior Advisor in the Office of Water for the EPA. “To date, 32 states have nutrient management plans, including all 12 of the hypoxia task force states. “

John Lawrence, Associate Dean and Director of the Iowa Nutrient Research Center at Iowa State University, has been leading Iowa’s nutrient management effort. The approach has focused on actionable, yet voluntary steps as historically farm organizations have resisted proposals that require or mandate reductions.

Nutrient programs can cost the farmer money in the short run, ask them to change the way they have been doing things or, in some cases, ask them to do more than before. To ease the transition, the EPA has offered financial incentives to lessen the economic burden of making environment conscious changes.

Lawrence explains that there are many different nutrient management methods from fertilizer reduction and grass buffers to wetland protection and bioreactors, structures constructed to intercept water and help break down nutrients. Research projects like CenUSA Bioenergy are seeking to develop grass-based biofuels and bioproducts that are both profitable and have the potential to improve water quality.

Lawrence said that Iowa will be monitoring the environmental impacts over the long term to see if more positive environmental results can be achieved. Iowa has agreed to EPA’s clean water reduction request, setting a goal to reduce nitrogen and phosphorus loading by 45 percent. Although ambitious, the plans have been criticized for not setting timelines for achieved reductions, something environmental groups feel is essential to achieve progress. 

Although it is uncertain what impact the state nutrient strategies will have, expectations for nutrient reductions are high and many farmers are adopting more aggressive nutrient management on their fields.

“Everyone wants clean and safe water. Nitrates and algal blooms can be health hazards,” Gilinsky said.

You can learn more about Iowa’s nutrient management strategy here: