Autonomous agriculture

Thanks to ongoing research, robots are advancing in the fields to take on pesky weeds, saving hours of tedious labor and the application of potentially hazardous herbicides to ensure a healthier, more abundant crop.

During the 2026 Midwest Farm Energy Conference June 17 at the University of Minnesota Morris, John Larson, renewable energy researcher with the West Central Research and Outreach Center, presented an overview of WCROC’s progress in agricultural robotics. He began his talk by pointing out that 98% of Minnesota’s nearly 8.5 million acres of corn harvested in 2025 had pesticides applied during the growing season, and 78% had glyphosate applications.

“Weed control using herbicides has been very effective but may have unintentional and harmful consequences to our air, land, water and wildlife resources,” Larson said. “One of these consequences is herbicide drift to adjacent land with negative impacts on desired native plant species, including pollinator habitats. Another is the evolution of … superweeds; globally, the resistance to herbicides by weeds is increasing. As of 2021, the number of unique resistant weeds in the United States was 138, the highest worldwide.”

While weed-hunting robots present themselves as a more efficient solution for field weed control, there are challenges in navigation, vehicle control, obstacle detection, field size and conditions, and weed identification and removal. WCROC’s goal in developing a weeding robot is to reduce herbicide impacts, replace fossil fuels with locally produced clean energy, save time and advance the field of agricultural robotics.

The first phase of WCROC’s initiative culminated in 2021 with the “CowBot,” an electric tractor for mowing organic pastures. The vehicle weighed about 1,800 pounds and operated with a 30-kilowatt electric motor powered by a 28-kilowatt-hour lithium-ion battery pack. As part of the project, the CowBot was equipped with a cargo trailer that carried a 15-kilowatt-hour battery, 3 kilowatts of retractable solar panels on the roof, a charger and climbing ramps so the mower could recharge without the need for an installed structure.

“The navigation … included both low-level navigation capabilities and high-level path and coverage planning,” Larson said.

The project’s second phase involved figuring out which weed removal method would work best for a robot. Mowing was found to be the most effective at preventing mature weeds from going to seed; other methods included various configurations of scythes and shears, as well as blasting a weed with nitrogen.

“The 40-watt carbon dioxide laser was good at cutting weeds at close distances but must be moved forward at slow speeds to cut or significantly damage weeds,” Larson said.
“This was tested using a pushcart, … which resulted in an estimated speed of one-one hundredth of a mile per hour, an unacceptable speed.”

WCROC then tested their Weed Terminator robot and its ground-engaging tools. However, the robot could only manage just under half an acre per hour and had difficulty mowing overgrown, mature weeds.

The third project phase resulted in the Lukas robot, named after three consecutive German foreign exchange students at UMN Morris who helped with the project. The robot was built around a used trench compactor, with a 10-kilowatt motor and a 26.5-kilowatt battery pack.

“Our robot is guided using a hybrid detection system — a machine learning model for the lane detector … to produce a binary mask of the lanes in an RGB (red, green, blue) frame, and a lane processor takes the binary mask and produces two parallel lines, which we can navigate,” Larson said. “A motion controller was developed to take in the two (angular) errors the perception system outputs and calculates the target angle for the vehicle to navigate.”

The Lukas robot continues to be developed by WCROC. This year saw the testing of its autonomous cultivation.

“Continual pressure to increase crop yields results in more stress on agricultural ecosystems,” Larson said. “Robotic weeding can eliminate some of this stress, allowing productivity gains without the negative side effects. Furthermore, an effective weeding solution for organic crops could lead to more widespread organic adoption, reducing the use of herbicides for weed control.”