Weed-eliminating robots

Clint Brauer had a problem. Marestail and pigweed were wreaking havoc on his soybean fields. The third-generation farmer employs organic and regenerative practices on his Kansas farm and realized there was no way to stay ahead of weeds on broadacre crops without relying on chemicals. 

“My goal has always been to get chemicals out of farming,” Brauer says. “I also knew I couldn’t simply say I wanted to get rid of chemicals without defining how I could achieve that.”

Then he had a crazy thought: What would happen if he cut the weeds using a mower?

“It seemed like a stupid idea that would never work,” Brauer says. “So, I reached out to a friend as well as our crop consultant at the time. Frankly, neither knew what would happen.”

Rather than discard his idea, Brauer decided to test the concept on his fields. For two summers, he used knives and rotary mowers on weeds, cutting at different heights. 

Those trials led to the creation of WeedBot, a robot that moves between the rows, cutting weeds at a half inch or lower while the crop is growing. Brauer recruited former colleagues Steven Gunter and Carl Sutter who had backgrounds in engineering to help build the prototype. 

In 2018, the trio launched GreenField Inc. and began testing WeedBot on Brauer’s soybean fields. Weighing in at about 350 pounds, the machine is 24 inches wide and 3 feet long, travels at about 3.5 mph, and is water-resistant.

Monitored from the edge of the field, a robot can cover about an acre per hour.

“On a 100-acre field, we would deploy a fleet of 10 WeedBots,” Brauer says. “In 10 hours, we would be done weeding the field.”

Bringing WeedBot to farmers

Two aspects of the GreenField team’s project intrigued MKC, a full-service agricultural cooperative that serves Kansas producers. 

First is the automated nature of the robots and the potential to possibly reduce worker hours through robotics and automation.

“Finding labor in rural areas has been increasingly difficult, so trying to utilize robotics and automation to be able to maximize the productivity of our labor and to provide a benefit to our members is something MKC is very interested in,” says Erik Lange, MKC chief operations officer. “Additionally, helping our farmer customers grow crops that meet the specifications of end users is something we strive to do.”

MKC can help its customers reduce herbicide applications by using GreenField robots and thus farm in a more regenerative manner to meet the market for regenerative products.

Employing a robot as a service business model, the WeedBot costs about $35 per acre. WeedBots usually weed up to three times per season depending on the climate.

While Lange says it is still too early to tell definitively where this technology will end up, MKC will continue to partner with innovative companies such as GreenField. 

“Ultimately, in this fast-changing environment, our job is to bring solutions to farmers that help solve their problems to be successful,” he says.

Although the robot can be used on any farm, Brauer says it was designed for those following regenerative principles where there is always a living root in the ground, cover crops are employed, and no-till is utilized. 

“There is no resistance to a spinning blade,” says Brauer, who hopes to expand the use of the WeedBot into other crops such as sorghum, cotton, and canola. He also plans to add more capabilities to WeedBot including micro-spraying, cover crop planting, soil sensing, and nighttime operations.