US ag interests are pressuring the country's EPA to back away from a proposal to restrict use of the herbicide, atrazine. They argue that it is critical for maize and sorghum growers and dispute the Agency's conclusion that the current mitigation measures are failing to protect aquatic ecosystems.

Farm groups including the American Farm Bureau Federation, the National Corn Growers Association, and the Agricultural Retailers Association, along with state farm bureaus and grower groups and the National Association of State Departments of Agriculture have all filed similar comments with the EPA warning of dire consequences for US farmers if the proposed restrictions are imposed.

"We are greatly concerned about the implications of the proposed revisions and the fact that, should they be adopted, it could mean the loss of atrazine for agricultural producers," according to the Farm Bureau. We adamantly urge the agency to re-assess this document… and use legitimate science and evaluate the chemical fairly. The loss of this crop protection tool could prove devastating for hundreds of thousands of American agricultural producers."

Revisions and concerns

The industry pressure comes amid growing concern by some farmers that the Biden administration is directing the EPA to take a more precautionary approach to pesticide regulation. Under President Biden's tenure, the regulator has banned use of the insecticide. chlorpyrifos, on food crops, agreed to take a close look at the possible cancer risks from glyphosate, and signalled its intent to consider stricter labelling requirements for seed treatments.

But environmentalists are urging the EPA to go further, and have long pushed for a ban on atrazine, a known endocrine disruptor that was banned more than a decade ago by the EU because of health and ecological concerns.

The EPA has so far resisted that call but in July proposed updating its 2020 interim registration decision for atrazine, the second most widely-used herbicide in the US. Maize and sorghum growers rely heavily on atrazine for weed control, with the Agency estimating that the country's famers annually apply some 72 million lb (36.2 million kg) of the herbicide to 75 million acres (30.3 million ha) of crops.

The EPA's 2020 interim decision included new mitigation measures to limit farmworker exposure and curb the environmental and public health impacts from atrazine, but critics said that the Agency had failed to fully consider the herbicide's toxicity and ignored ample evidence that it posed undue risks to human health and the environment. Environmentalists also filed a suit in the US Court of Appeals for the Ninth Circuit to vacate the registration, alleging that the EPA had wrongly relaxed the regulatory threshold intended to protect aquatic species, potentially harming the environment and undermining efforts to keep atrazine out of drinking water.

The legal landscape shifted with the Biden administration, which asked for a partial remand to address criticism about the EPA's decision to set the allowable level of atrazine in watersheds—referred to as the concentration equivalent level of concern (CE-LOC)—at 15 parts per billion (ppb).

The Ninth Circuit granted the EPA's request last December, prompting the new proposal to amend the 2020 interim decision. Central to the proposal is the EPA's call to revise the CE-LOC from 15 ppb to 3.4 ppb, a move that the regulator said would ensure protection for the "entire aquatic ecosystem."

The Agency is also proposing to bar the application of atrazine in saturated fields and during rain or when a storm event is likely to produce run-off from a treated area forecasted to occur within 48 hours following application.

The revised registration would include a ban on aerial applications of all formulations and restrict annual application rates for sorghum, field maize and sweet corn to 2 lb or less per acre (2.2 ha/kg) per year.

In addition, the EPA is proposing to add a "picklist" to labels that would require growers to select a combination of application rate reductions and/or run-off control measures when using atrazine in watersheds with concentrations that exceed the CE-LOC of 3.4 ppb. Those areas account for some 18% of all US watersheds.

Environmental and economic benefits

The ag interests contend that the new mitigation measures—and particularly the move to revise the CE-LOC—are unwarranted and do not reflect the real-world use and risks of atrazine.

The EPA appears not to be fairly considering the environmental and economic benefits of atrazine, according to the Farm Bureau. On the environmental side, the organisation says that the use of atrazine enables "added environmental benefits for farmers seeking to utilise conservation tillage and no-till practices".

"These methods help to conserve soil, preserve and increase nutrients, and improve water quality," says Farm Bureau. "In addition to trapping excess carbon in the soil and reducing greenhouse gas emissions, no-till techniques play an integral role in reducing run-off and protecting aquatic ecosystems and water quality. Without atrazine, many farmers would not be able to utilise these methods that provide environmental benefits."

On the economic side, the farm groups contend that atrazine provides a low-cost, long-acting weed control for farmers that helps boost yields and improve crop quality.

The Farm Bureau notes that the annual value of maize production in the US exceeds $50 billion and the value of sorghum tops $1 billion.

"Given the value of the markets and their impact on the economies in both agriculture and rural America, it is imperative farmers maintain access to atrazine as there is no substitute for this affordable, off-patent and well-understood product," the Farm Bureau says. It adds that the EPA estimates that atrazine saves maize farmers an estimated $8-20 per acre ($19.80-49/ha) and sorghum farmers $16-24 per acre ($39.50-59.30/ha).

Recommendations

The Farm Bureau and its allies are honing in on the CE-LOC, suggesting that the EPA set the level at 15 ppb, which had "resulted from years of exhaustive scientific review".

"There is no scientific reason to reconsider and change the published 15 ppb level of concern," the Farm Bureau says. "In fact, previous attempts by EPA to reduce the CE-LOC to this level were not supported by credible science and were based on studies EPA's own Scientific Advisory Panel rejected."

"At a minimum, EPA should convene a FIFRA Scientific Advisory Panel to study the science behind the currently proposed 3.4 ppb CE-LOC," the Farm Bureau says. "The arbitrary mitigation measures proposed by EPA will ultimately decrease conservation tillage and no-till practices, remove a reliable tool for farmers, increase expense, and possibly put at risk the very ecosystems the revisions claim to mitigate risks for."

by Jonathan Pegg, Senior Journalist

This article was published by S&P Global Commodity Insights and not by S&P Global Ratings, which is a separately managed division of S&P Global.