Low-flying planes will drop a pellet of herbicide called teburthiuron on areas plentiful with sagebrush. Teburthiuron is a soil-activated herbicide that stops photosynthesis.
The BLM has selected areas where sagebrush densities have surpassed historic, naturally occurring levels, according to a BLM news release.
The areas include east of Navajo Reservoir south to Counselor.
"Reducing the density of sagebrush will result in an increase of native grasses, forbs and other herbaceous vegetation," Jeff Tafoya, a range land management specialist for the BLM, said in a prepared statement. "Our goal is to improve species diversity, which will benefit wildlife, range lands and the watershed."
Tafoya said the herbicide will have no affect on grasses and forbs and the pellets won't drift outside the treatment areas. The pellets won't be dropped near waterways, he said.
The BLM treats dense sagebrush areas to reduce the risk of fire damage.
In 2011, the BLM treated 214,600 acres of sagebrush. The agency plans to treat 466,000 acres in 2012, according to the BLM's website.
The Farmington Field Office is scheduled to thin safebrush in the county from Oct. 15 through the end of the month.