Grazing cheatgrass reduces fire threats

Research projects in Nevada and Oregon have demonstrated the value of late-season grazing to remove cheatgrass and reduce fire danger. According to Bob Alverts of Science and Management Consulting, Tigard, Ore., fire has become the biggest threat to natural resources in Western states, destroying wildlife habitat, timber resources and livestock forage.

Grazing cheatgrass reduces fire threats

 

Research projects in Nevada and Oregon have demonstrated the value of late-season grazing to remove cheatgrass and reduce fire danger. According to Bob Alverts of Science and Management Consulting, Tigard, Ore., fire has become the biggest threat to natural resources in Western states, destroying wildlife habitat, timber resources and livestock forage.

“A map showing location of large fires since 1970 was recently prepared by the National Interagency Fire Center in Boise, Idaho. A huge area in the northern Great Basin is where most of the serious fires have been concentrated. It correlates with range adjudication, when BLM started reducing cattle grazing on public land, under the false notion that this would improve rangeland health,” Alverts says.

“They forgot that ungrazed forage becomes fuel. Then nature removes it with lightning-caused fires. With excess fuel loads, fires burn hot enough to destroy all plants; former grass and shrub plant communities are replaced by invasive annual grasses like cheatgrass. Fire return intervals are shortened, fire burns more readily the next time, and range condition and fire danger keep getting worse,” he says.

“Using animals to manage vegetation works. We don’t see as much fire damage on a properly grazed range or well-managed forest. It’s all about plant density and fuel loads,” he says.

Land management agencies need to allow more grazing, not less, to reduce fuel loads. “I was in southern Idaho a few years ago looking at a fire reduction project on the Snake River Plateau. A rancher had grazed 1,000 yearlings on state land all winter, taking all the AUMs [animal unit months] that he was allowed, and then removed the cattle. In late May a lightning storm hit that area, and there was still so much fuel that it burned the entire pasture. If we don’t take enough grass off, it is still going to burn,” says Alverts.

Grazing in late fall removes the old dry grass. “The seeds remain viable for several years, but without the old grass to provide shade protection, the new plants don’t thrive as well the next spring and don’t compete as much with perennial grasses. If cattle keep grazing the cheatgrass off every fall, soon the perennials move back in.”

Cheatgrass projects

Alverts was involved with a cooperative project between the University of Nevada, the Bureau of Land Management’s Burns District, Oregon Cattlemen’s Association, Oregon Beef Council, Harney County, and Bill and Pat Wilber’s Drewsey Valley Ranch in southeast Oregon. The ranch has a permit for up to 400 cows on a 14,000-acre allotment, and for the past three years, BLM allowed them to graze it in the fall.

“The perennial grass is dormant at that time, so grazing won’t hurt it. This allows us to really hammer invasive annual plants like cheatgrass. When the rancher distributes protein supplement around the pasture we can influence how and where the cattle graze cheatgrass,” Alverts explains. Over time this enables perennial grasses to come back.

“I have another project on the Roaring Springs Ranch. It’s only a 1,400-acre pasture, but it’s on private land” so they can manage it any way they choose. “They put 1,500 cows in there the first year [2012] to eat all the cheatgrass. There was 2,000 pounds of cheatgrass per acre in that pasture. The cows were there 60 days and grazed it off to a fuel load less than 100 pounds per acre,” he says.

“When we get below 200 pounds per acre, fire risk is significantly reduced. The likelihood of catastrophic fire is largely gone when fuel loads are under 100 pounds per acre,” Alverts says. “With competition from cheatgrass gone, we are starting to see shrubs come back and perennial grass — plant communities that are not as prone to catastrophic fire. We have changed the plant community in a positive way.”

Smith-Thomas is from Salmon, Idaho.

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alverts

Oregon ranch part of research project

Bill and Patsy Wilber’s Drewsey Valley Ranch lost 39 head of cattle on their range allotment in southeastern Oregon during the Buzzard Complex fire in July. “This is a perfect example of the problem we are trying to prevent. We are currently in a research project in concert with University of Nevada,” says Wilber.

Begun in 2012, the study looked at how fall grazing could reduce fuel loads. Wilber moved 330 cows into a 14,000-acre pasture in early October for more than 90 days of grazing on cheatgrass-dominated range. “Prior to moving the cattle into this pasture, some of the cows were evaluated as to body condition score. Those same cows were evaluated when brought out of the pasture in January. There was improvement in body scores and weight gain,” he says.

“In 2014, we again body-scored 20% of the cows prior to going into the pasture, and again when they were removed. The body condition scores were substantially higher after the cattle came out of the cheatgrass pasture,” he says. They did very well on the dry cheatgrass, supplemented with protein.

“The late-season grazing has been successful in three ways,” he says:

The cows ate the buildup of fuel.

It saved substantial cost in hay during that period; protein supplement was cheaper than hay.

The cattle maintained themselves well and most gained weight.

The Bureau of Land Management cooperated in this project by allowing cattle to be out there later than usual. “They recognize that fuel buildup is a serious issue, and the only way to remove it is by grazing. We put our cows into a very large pasture that burned in 2007 because it had too much fuel load, and after the fire, it grew back even thicker to cheatgrass and medusahead — a weed that is also a significant problem,” says Wilber.

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bill wilber

This article published in the June, 2015 edition of WESTERN FARMER-STOCKMAN.

All rights reserved. Copyright Farm Progress Cos. 2015.

Crop Management

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