New tech, old problem: How drones accelerate control of noxious weeds in eastern Idaho
Published at | Updated at
Steve Stuebner, Idaho Capital Sun
ST. ANTHONY (Idaho Capital Sun) — The South Fork of the Snake River, near Idaho Falls, is a treasured, native Yellowstone cutthroat trout fishing stream and a popular recreation area.
Multiple agencies work together to combat noxious weeds in the South Fork Canyon via the Upper Snake River Cooperative Weed Management Area.
Last year, a 5-acre steep hillside needed treatment for hound’s tongue and musk thistle in the South Fork canyon.
The Fremont County Weed Department treated the weeds with its big DJI T40 drone.
“There was one large hillside where a full crew with backpack sprayers spent four days on it. We took the drone up there, and took care of it in a couple of hours,” said Chase Hirschi, assistant weed manager for Fremont County and the drone pilot.
Officials with the Caribou-Targhee National Forest agreed.
“We have an area that’s really hazardous to walk, cruise up with a backpack, you can’t drive a vehicle on it, so we said, let’s try this out,” said Greg Hanson, range management specialist for the Caribou-Targhee National Forest.
“It was great. I got to sit at the bottom of a hill and watch five acres get treated without hiking up and down 200 vertical feet through lava rocks to treat the weeds,” he said.
Drones allow Idaho’s Fremont County to assist other public land agencies
Fremont County has been making big strides in its noxious weed control program by adding three drones to their fleet.
The drones allow Fremont County to treat more than 6,000 acres a year while also assisting partner agencies to treat weeds on state and federal lands.
The use of drones in natural resources management and agriculture is growing rapidly. Fremont County officials want to be on the leading edge of that trend.
“The drones have found their place in our county. They’ve performed well. We enjoy using them. They’ve done a good job,” Hirschi says.
“We’ll do contract work, the county work, roadsides, barrow pits, also rangelands, also have contracts with the Forest Service, BLM, railroad, (and) highway,” he said. “We do all of that work as well.”
Preventing the spread of noxious weeds is a big job for Idaho counties statewide. The spread of noxious weeds on Idaho’s rangelands is considered one of the top three threats to the shrub-steppe ecosystem. Noxious weeds can out-compete native plants, reduce natural food sources for birds and wildlife and increase the threat of destructive large wildfires.
“Rangeland pastures and non-crop are our specialty,” Hirschi says.
Fremont County invested in its first drone two years ago.
“We had a landowner who showed interest in it, and Bryce, my boss, wanted to stay current with technology,” he said. “The landowner heard about that, and he said, hey, this could be really beneficial to me as well. I’ll help put in for it, and let’s get going.”
The landowner contributed to the cost of the first drone, liked the results, and the Fremont County crew was off and running.
“He had cattle and rangeland. We sprayed a lot of his rangeland. Hard to reach areas for leafy spurge,” Hirschi says.
The county’s drones come equipped with tanks for holding herbicides approved for noxious weed treatment. The county’s smallest drone comes equipped with a two-gallon tank. That’s enough to cover one acre of ground. Their other drones hold five gallons and 10 gallons each. The bigger the drone, the faster you can cover a field.
“A lot of the jobs this small one has taken on. We used to do with backpacks. A backpack carries about a quarter-acre of herbicide at a time, you spend hours hiking. This knocks it out in minutes,” Hirschi says.
Treating weeds in Island Park
Another drone project that worked out well was treating weeds on the face of Island Park Dam.
“They used to spend all day, backpacking across that dam. This goes back and forth and does it all in 10-20 minutes,” he says.
Fremont County also carefully sprayed the islands on the world-renowned Henrys Fork of the Snake River, a blue-ribbon trout stream.
“In the past, there’s been no weed control on those islands. And it’s all being taken over by Canada thistle. Fly fisherman complain about it,” Hirschi says. “Took the drones out there, I could map them from the aerial map and what not, flew the drones in, sprayed all of those islands, super easy got it all taken care of.
“We’ve done that for a couple of years in a row now — helping in those areas,” he said.
The drone controls allow the operator to map the perimeter of the area you’d like to treat. Hirschi explains. “Most of the jobs I just set a boundary, it will grid it out, and I basically click Go. From takeoff to landing, I just monitor it,” he says.
Hirschi tracks the spray area and saves the digital image to keep track of areas that have been treated.
The drones do a more complete job than a human operator can do, he said. “I’ve actually seen more effective control with drones, in my opinion. Better coverage, no skips over overlaps, plants are reacting faster; I’d say they’re doing great.”
The drones help reduce damage to all-terrain vehicles used to spray weeds as well.
“People take their 4-wheelers to places where they shouldn’t as well. With 4-wheeler accidents, you have repairs, workmen’s comp, all of that comes in,” he says. “If the drone crashes, no one is at risk, no one’s hurt, the equipment is not being broken, it saves a lot of money there as well.”
Hanson says the Caribou-Targhee will be looking to create its own aerial weed control program in the future. The forest’s long-range management plan has been updated to allow aerial control of noxious weeds.
“We’re looking forward to getting a drone program of some type,” he said. “We’ve probably got enough acres we could treat with a drone all summer and maybe not get it all then.”
The same drones come with an attachment for spreading seeds to replant or reclaim a site.
The Jenkins family, for example, worked with the county to seed the banks of a gravel pit.
“That was a big step forward to reclaiming it and putting back the vegetation we need to hold the slopes,” said Neal Jenkins, owner of Jenkins Gravel, near St. Anthony. The gravel pit was initially developed after the failure of Teton Dam.
“I was telling you how great the county guys are, the county commissioners, everyone in the county is great to work with,” Jenkins says. “Taking ideas and doing something about it, and not just talking about it. Kind of putting their neck out there a little bit, why can’t we do it?
“I think they’re doing a great job,” he said.