Posted 31 August 2015. PMN Crop News.
Atrazine Monitoring Continues to Help Reduce Runoff
Source: Louisiana State University Press Release. www.lsuagcenter.com
St. Gabriel, Louisiana (August 10, 2015)--Representatives from the chemical manufacturer Syngenta shared information on monitoring atrazine, one of the most commonly used herbicides in agriculture, at a meeting of Louisiana agriculture officials on Aug. 6 at the LSU AgCenter Sugar Research Station.
In Louisiana, atrazine is used primarily in corn, sorghum and sugarcane production.
Mark White, regulatory stewardship manager for Syngenta, said in 2000 the EPA determined that atrazine was not likely to cause cancer. Atrazine went under a comprehensive scientific reevaluation from 2009-2012.
As part of the monitoring effort, White said, Syngenta has examined 75 sites in watersheds across the country for the past 13 years. The monitoring site in Louisiana is currently the Boeuf River in Richland Parish.
Another site in Iberville Parish had been part of the monitoring program but was released in 2013 because sufficient progress had been made in lowering atrazine levels in that watershed.
“The monitoring is to help the EPA set a level of concern. This is a threshold for aquatic life criteria. The goal is to protect algae because it is a lower level organism that plays an important role in the life cycle,” White said.
LSU AgCenter sugarcane specialist Kenneth Gravois said atrazine is not a major runoff issue in sugarcane crops in Louisiana. “The fact that the site in Iberville Parish is no longer being monitored after nearly 15 years shows it is not a major problem,” Gravois said.
White shared data that looked at atrazine levels over the past five years (2010-2014) in the Boeuf watershed. The data showed that levels were lower in even years and higher in odd years. The data also showed that rainfall was higher during the odd years which may have caused higher atrazine runoff.
White also indicated ways to reduce atrazine runoff. “One of the best ways is label education. Growers need to follow that label and the directions on it,” White said.
He said careful field evaluation and preparation can identify potential problem areas that may cause issues in the future.
“Rate reduction is another method to reduce runoff,” White said.
According to White, incorporating or mixing atrazine in the soil is the best way to reduce runoff, but it is rarely done because it would conflict with other conservation practices such as no-till farming.
Other techniques to reduce runoff include splitting the application into two parts instead of putting it all out at once and by maintaining vegetative strips of at least 60 feet along fields that border a waterway.
The presentation was part of the registration review for the herbicide, which is required by the U.S. Environmental Protection Agency.
Representatives from the LSU AgCenter, the Louisiana Department of Agriculture and Forestry and the American Sugar Cane League attended the meeting along with agricultural consultants.