On Minnesota farm, robots equipped with hoes test new approach to weed control – InForum

In a sugar beet field a few miles east of Moorhead, small four-wheeled robots roll up and down the rows of beets.

Powered by a solar panel, the robots use cameras to spot weeds and then guide sharp-edged hoes to pull them out of the ground.

This is the first year that Redmond, Washington-based Aigen has deployed the weeding robots.

“We’re using a method that’s been around for thousands of years,” said Chris Benner, Aigen’s director of field operations. “It takes just a hoe to pull weeds out of the ground, with a little extra technology built in.”

Today, farmers use herbicides to prevent weeds from invading their crops. But nature adapts very well and weeds are increasingly resistant to pesticides.

Kochia and tuberous amaranth are two common weeds with widespread herbicide resistance.

A single surviving plant can spread thousands of seeds and grow more resistant weeds.

Weeding robots are designed to be simple. The goal is to set them down and forget them.

However, during this first year of deployment, teams of operators and engineers are working from trailers in the fields, monitoring the robots and tweaking software and hardware to improve performance.

Dan Gunderson / MPR News

Weeding robots look simple as they roll at a leisurely pace through a field of sugar beets. They are equipped with a solar panel, four wheels, cameras and two sharp blades on poles.

What is not visible is the artificial intelligence that operates the machine.

“Trying to figure out what a sugar beet is, what a weed is, and then pairing that with the ability to kill it while it’s moving, that link between software and hardware, is a very difficult thing to do,” Benner said as he watched a robot work. “That’s definitely the bread and butter of what makes the system work.”

Rich Wurden, Aigen’s co-founder and CTO, is among those working in a tech-packed trailer on the edge of a farm field. The former Tesla engineer started the company after a family member who farms in the Red River Valley told him about the problem of herbicide resistance.

Reducing pesticide use is a key goal for the company.

“There aren’t many good alternatives to chemicals,” he said. “Right now, we see herbicide resistance and immunity. But there’s no resistance to a steel tool.”

This summer, Aigen brought 50 robots to the Red River Valley. They work only in the sugar beet fields. It takes about 10 robots to patrol a 160-acre field. They can weed the entire field in a week, from sunrise to sunset. Then they do it all over again.

Dan Gunderson / MPR News

The company is keeping a low profile, but Wurden says there is a waiting list of farmers who want to try the robots.

“We’ve had to say no to a lot more farmers than we’ve said yes to,” he said. “We’ve done very little advertising because there’s so much interest in herbicide-resistant weed control.”

Dan Gunderson / MPR News

The goal is to increase the number of robots to 500 next year and begin using the machines in soybean fields. Eventually, the company wants to build a manufacturing plant in the Midwest so the machines can be built closer to a primary market.

Neil Rockstad is an Ada farmer and president of the American Sugarbeet Growers Association. Robots are working in one of his fields, and he likes what he sees.

“I think they’re doing a great job,” he said. “I guess we’ll know the results in a couple of weeks as to how well they’ve managed to control the weeds, but my initial reaction is that it looks really good.”

Rockstad remembers when migrant farm workers armed with hoes controlled weeds in sugar beet fields. Then sugar beets were genetically modified to make them immune to the herbicide Roundup. That eliminated manual labor and made weed control easier — until weeds evolved to resist Roundup and other similar herbicides.

Rockstad will evaluate the robots’ effectiveness and cost per acre before committing to a robotic future. But he’s optimistic he can reduce herbicide use in the future.

“I would love to live in a world where weeding robots take over everything and I don’t have to spray a single acre, and I think the consumer would be thrilled with that,” Rockstad said. “I don’t know if we can get there, but I’m certainly not ruling anything out when it comes to technology and our future.”

That’s unlikely to happen anytime soon. The robots are still learning. This year’s wet weather taught engineers some tough lessons about the sticky clay of the Red River Valley.

But Wurden sees the systems improving every day, and the company is working to fix bugs before expanding. The idea is to create a truly autonomous machine that will run on its own and send a message if it breaks down.

“We want to make sure farmers really like what we’re doing before we start developing it,” Wurden said.

“It’s pretty impressive how quickly they can take that picture, process that information and then get to a weed,” said Moorhead farmer Trent Eidem.

Eidem is concerned about the cost of buying or renting the robots, but he is eager to see how the company develops the machines.

“I think a few years ago, agriculture was slow to adapt to technology and that’s not the case anymore,” Eidem said. “Agriculture is a very tech-friendly industry and everyone wants to take advantage of what they can do to make their season successful.”

In addition to its plan to move the robots into soybean fields next summer, the company is developing other tools that it hopes will add value to the machine. The robots could be used to test soil nutrients or scan plants for early signs of disease.

And during the off-season, Benner said, the solar panels can generate electricity to help power the farm store.