The Hill Country

Steep slopes don’t deter Idaho seed grower from irrigating with center pivots

Published online: Jul 02, 2018 Irrigation, Grower of the Month Andrew Oerman, Valley Irrigation
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This article appears in the July 2018 issue of Potato Grower.

The Atchley family ranch consists of 5,000 acres near Ashton in southeastern Idaho, just southwest of Yellowstone National Park. Their land lies on the Northern Snake River plain, with clean, mountain spring water. The soil is rich volcanic dirt. Clen Atchley says growing there results in fewer soil-borne viruses, bacteria and nematodes, and his crops experience less pressure from insects such as potato beetles and peach aphids.

It sounds like the ideal environment to irrigate potatoes with center pivots, right?

But did we mention his farmland is also at an elevation of 5,100 to 5,500 feet, and that some of his fields rest on inclines so steep trucks can’t climb them?


Tall Hills, Short Season

Theirs is a close family operation, with Clen’s daughter, Laura Pickard, managing the operation’s potatoes, canola and wheat. His son-in-law, Clay Pickard, handles the hay and the cattle. Clen’s wife, Emma, manages their greenhouse, Ashton High-Tech Seed, and somehow finds time to serve on the Idaho State Board of Education. Atchley “tries to stay retired, but fill[s] in when needed.” The operation also has six full-time employees who have worked on the farm for decades and are an essential element in the farm’s success.

“Our ground is close to the timberline and close to mountains, with a rolling base,” Atchley says. “There’s 30 feet of soil some places, one foot in others.”

The Atchleys’ landscape might be more extreme than most, but they face the challenges common to all potato growers, like concerns about PVY. “Keeping disease readings low is important,” he says. “And, of course, you need the right price and a good growing season.”

The short growing season in Ashton—longer winters mean Atchley usually can’t even start until May 1 or later—means seed potatoes are the best option for most growers in the area.

“More seed potatoes are grown in Ashton than anywhere because of the short season,” he says. “We keep the potato ground on a four- to eight-year rotation, which is beneficial for seed potatoes.”

The Atchleys harvest up to 300,000 sacks per year, selling seed primarily to other Idaho and Oregon potato growers.


Pivot Practice Makes Potatoes Perfect

Atchley passes on the many lessons learned over his 48 years in farming, including those related to different methods of irrigation. His grandfather homesteaded the land in 1901 but struggled to clear the volcanic rock. His father tried flood irrigation, but “it didn't take too long to figure out that didn’t work too well on hills.” The right amount of water is important to avoid runoff, Atchley explains: “Once an erosion line starts, you have to live with it for the summer.” Similarly, if the snow melts too fast, it can create gullies; the Atchleys create dams to help avoid that issue.

Atchley himself tried hand lines and wheel lines to irrigate his fields, but those weren’t satisfactory, either, because those methods were too labor-intensive and not responsive enough to the precise water application needs of potatoes, especially on steep inclines.

Today, Atchley’s operation has 30 center pivots from Valley Irrigation irrigating 4,000 of his acres. “It took a few years to make circles work on hills, too,” he admits with a chuckle. “Pivots can control the quality. As we learned how to use pivots, we could raise a better quality of potato—a prettier potato.”

The same gullies that spring runoff and hard rains can create are also a risk with pivot tracks, Atchley says, “but if you keep the soil loosened up, it’s not generally a problem.”


An Uphill Climb

Attractive potatoes aside, the hills Atchley’s pivots have to climb can be ugly. “Some of them are at least 40 degrees,” Atchley says. In fact, their harvesting equipment doesn’t work going up the steepest hills. “We have to harvest going downhill on some fields.”

The pivots Atchley purchased in 1982 continue to work well. He worked with Trent Angell of Golden West Irrigation, a Valley dealer in Rexburg, Idaho, to modify his pivots.

“We worked together to put three-wheel drives on the pivots that wouldn’t have the traction to handle the terrain,” Atchley says.

In addition, most of Atchley’s pivots need spans of 146 feet and shorter because, Angell says, their undertrussing and nozzles would drag on longer spans as they went over hills. The angle of incline isn’t the only challenge Atchley’s operation faces due to the often harsh landscape; one 120-foot span crosses a deep canal. Another wades through a shallow lake, which “took a bit of engineering to make work.”

These factors could add up to potential difficulties and damaging downtime, so to monitor his pivots, Atchley’s operation employs remote management technology and GPS tracking.

“We can check the pivots on computers and cell phones,” he says. “New technology can be great.”

It’s also important to monitor the pivots because potatoes are as sensitive to too much water as they are to not enough.

“Timing is critical, and poor irrigation can make a lot of off-type tubers,” Atchley says. “Laura is in charge of irrigation, and she seems to have it down as good as it gets. She understands potatoes and how to maximize production, despite all the meteorological and geological challenges.”

“Clen is someone who knows what he wants,” sums up Angell. “You do it right the first time; you don’t cut corners.”

Which is important when you’re irrigating in a circle on sharp slopes.