Exotic-killing herbicide is ousted from the range

BLM's most promising tool for fighting cheatgrass backfires in Idaho

  • Dan Schaeffer holds a handful of the dust that carriedOust onto his sugar beet fields

    Guy Hand
  • Map of Highpoint Fire near Paul, Idaho

    Diane Sylvain

PAUL, Idaho - Last spring, Dan Schaeffer noticed something odd going on in his fields. He'd been farming this patch of southern Idaho most of his life and had never once seen sugar beets acting the way these were. They would pop out of the ground, spread their leaves, and just when he thought all was well, the plants would turn almost purple, start rolling up, and, after a short, dramatic struggle, die.

The same drama was playing out in his neighbors' fields. "We had some guys that had just a beautiful, perfect stand," Schaeffer says, "and then two days later there was nothing there. All dead." It didn't add up. "You'd look out there and think, this crop needs water. So we'd water." Some farmers irrigated until ponds formed in their fields. But that just made things worse. It was as if some enemy had sneaked onto this farmland near Paul, Idaho, and salted the earth.

Many calls, consultations, and soil samples later, Schaeffer and his neighbors began to connect their dying crops to a helicopter they'd seen flying west of their fields the previous November. It had tacked back and forth across a large expanse of public land devastated in an August fire. They'd assumed the chopper was reseeding that barren ground. But instead of seed, it was dropping a potent herbicide called Oust.

A state investigation confirmed that the Idaho Bureau of Land Management had contracted the helicopter company to spray Oust adjacent to the farmers' fields as part of a program to eradicate non-native grasses and noxious weeds from public rangeland. But tests proved the DuPont-manufactured herbicide had drifted, via strong winds and dry, fire-charred soil, onto the nearby farms.

This April, more than 100 farmers sued the BLM, DuPont, and the spraying contractors. Their suit alleges that more than 100,000 acres in 11 counties were damaged by Oust, resulting in the loss of hundreds of millions of dollars in farm revenue.

Yet bad as the agricultural losses were, public rangeland losses could be worse: The BLM suspended its use of Oust after the incident, thus losing its most effective tool to restore the once vast expanses of sagebrush on the Snake River Plain - an ecosystem, the agency says, that's on the verge of collapse.

Magic potion?

Cheatgrass, an alien annual grass, slipped into North America via shipments of grain in the late 1800s and exploded across the West (HCN, 5/22/00: Fire and cheatgrass conspire to create a weedy wasteland). As cheatgrass and other non-native weeds invade the range, they turn it into a tinderbox more than 500 times as likely to sprout flame. Schaeffer and his neighbors frequently fight fires like the one that hit the area west of Paul that August afternoon. But that blaze burned extra hot. Although Schaeffer's property made it through, neighboring farmer Perry Vantassell's did not.

"Once it hit a power line out there, it was all over," Vantassell says. "It was just rolling in. It burnt through 400 acres of barley. We lost several hundred tons of hay. We lost corn silage. We lost sheds. It was devastating for us."

Vantassell was able to save his cattle, pulling them out of barns, their hides smoking. But another neighbor lost 700 head. "We helped shoot and bury cows for days," he says. That, however, was just the beginning. "Then the dust started coming. And I mean it just blew. There was days you couldn't even see the sun. There was drifts across the road."

The Oust-spraying helicopter that clattered over the horizon in November was the culmination of a carefully developed BLM program to combat fire-prone weeds using the DuPont herbicide.

South of Boise, near where the program began, BLM rangeland ecologist Mike Pellant takes in the view. Decades before, he says, this land was covered in sagebrush, native bunch grasses, and a delicate crust of lichens and moss - as was much of the Great Basin. Today Pellant sees mostly cheatgrass.

"Estimates are that 250 million acres (across the country) were once covered with various species of sagebrush," he says. "We've lost 100 million acres of that sagebrush now."

The BLM began testing Oust in May 1992, starting with small plots, then progressing to larger sites like the Snake River Birds of Prey National Conservation Area. Home to the highest concentration of nesting raptors in North America, the NCA's native habitat is disappearing - along with the food sources that hawks, eagles, and falcons depend on. In the last 15 years, the number of prairie falcon nesting pairs has dropped by half.

Oust showed real promise in the Birds of Prey NCA. It killed cheatgrass far more effectively than other weed-control tactics, and gave native plants and animals a chance to reestablish themselves.

"Whenever we plowed or disked," says Pellant, "we created an environment that was conducive to other weeds coming in, or if our seeding failed, for cheatgrass to become even more dominant." The herbicides, however, don't disturb the soil, and Oust did a particularly good job of killing cheatgrass without harming native plants.

For several years, the Idaho BLM worked with DuPont, fine-tuning the herbicide's usage until it seemed certain that Oust could be safely applied. In 1996, Idaho moved forward with full-scale spraying in concert with traditional weed eradication methods. BLM offices in other states soon followed Idaho's lead.

Coming up empty

But the parched, flour-fine soil near Schaeffer's farm was the perfect medium for lifting Oust into the air and floating it east over sugar beet, hay, grain and corn fields.

BLM public affairs specialist Barry Rose acknowledges the incident was tragic, but he maintains the agency was following the protocols it had developed with DuPont. "The label says not to apply Oust unless there's a likelihood of precipitation," says Rose. "That's exactly why we apply Oust in the fall, because that's when there's the highest likelihood that you'll have precipitation." BLM sprayed 34,000 acres of rangeland in south-central Idaho, including the nearly 20,000 acres that burned in the fire. But little rain fell that fall, and the next spring crops began dying.

Today, a year and a half after the BLM sprayed the herbicide, no one is sure how long the damage will last. One estimate suggests six years. This season, Dan Schaeffer, Perry Vantassell, and many others have rented fields farther from the affected area and planted lower value, more Oust-resistant crops. Some farmers have simply declared bankruptcy.

A settlement from the lawsuit would help. But the federal tort claim process is slow, and another growing season will pass before there's even a chance of compensation for the farmers.

Even after the case is decided, the cheatgrass - the enemy common to both plaintiff and accused - will remain. And now, after over a decade of testing its weapon, the Idaho BLM must start looking for a replacement for Oust. At the earliest, the agency estimates it could have a new herbicide in the field by the fall of 2004.

"It puts us in a holding pattern," admits the BLM's Pellant as he works his way through what was, until recently, a weed-free stand of sagebrush where he brought visitors to see a remnant of good rangeland habitat. Now, even this ground is sprouting cheatgrass.

"It's kind of sad to see this site," Pellant says. "If this little patch burns, cheatgrass will completely take over."

Guy Hand is a writer and radio producer living in Boise, Idaho.


  • Mike Pellant, Idaho Bureau of Land Management, 208/373-4000, www.id.blm.gov;
  • Idaho Department of Agriculture, 208/332-8500, www.agri.state.id.us.

Copyright © 2002 HCN and Guy Hand

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