Atrazine an Important Tool for Conservation Farming

In a case of supreme irony, a recent report from Environmental Protection Agency (EPA) is highly critical of atrazine, an herbicide that helps reduce soil erosion and runoff, keeping our soil healthy and our water clean.

EPA released its draft ecological risk assessment for atrazine in June 2016, as part of the re-registration process for the herbicide. If the recommendation in the assessment stands, it will effectively ban atrazine, which plays an important role in conservation cropping systems that reduce soil erosion.

Tillage, or turning up the soil, is an effective means to control weeds, but it disturbs the top layer of the soil, leading to a loss of as much as 90 percent of the crop residue from the top soil. The practice damages soil and leaves it exposed to erosion, particularly by wind and water. Soil erosion leads to more runoff of fertilizer and pesticides.

The introduction of atrazine and other herbicides significantly changed conservation tillage practices, said Bob Hartzler, professor of weed science at Iowa State University.

"Atrazine was one of the first products used on a large acreage because it is broad spectrum and has a wide margin of safety. Prior to that tillage was the primary means of weed control. Atrazine makes it possible to reduce trips across the field," said Hartzler. "The extra two or three trips farmers were making across the field to control weeds loosened the soil and made it prone to erosion."

Farmers have made significant progress adopting reduced tillage and no-till methods of growing a crop, and atrazine plays a key role in making these more sustainable practices possible, Hartzler said. 

"Atrazine isn't the only tool used today, but it has a unique chemistry that makes other chemicals work better. That synergy is documented, and the benefit is it allows farmers to manage weeds effectively, especially problem weeds, and it allows reduced use of these other chemicals," Hartzler said.

Atrazine is one of the best tools on the market today for combatting resistant weeds that waste water and nutrients. It has also been shown to improve wildlife habitats.

NCGA President Chip Bowling called on EPA to consider the whole picture when evaluating the environmental impacts of atrazine and other crop inputs.

"The EPA's mission is to protect the environment. Atrazine plays an important role in sustainable agriculture, and banning it will hurt the environment, not help it," said Bowling.

"Farmers care deeply about keeping America's land and water safe for our families, our neighbors and our communities. The safe, responsible use of herbicides such as atrazine are an important part of modern, sustainable farming. Farmers need access to tools that ensure a safe, abundant, and affordable supply of food and fuel for consumers around the world," said Bowling.

Nebraska Corn urges farmers to voice their concerns about EPA's atrazine proposal at fightepa.org. The deadline to submit comments is October 4.