THE SCOOP ON AUTONOMUS WEEDING ROBOTS

In July I attended a field day hosted by the University of Vermont Northwest Crops and Soils Program featuring autonomous weeding robots. These machines, developed by a company called Greenfield Robotics, are designed to fit between 30-inch rows and mow down weeds as they go. The machines can navigate corn rows on their own for several hours before returning to a base location for charging or a battery swap.

The goal of the company is to reduce or eliminate chemical herbicides through periodic mechanical clipping of the weeds. As you might expect, this doesn’t kill weeds to the root but just chops the top off of them. Back when I was in school I decided to test a similar approach to weed control by modifying a single-blade Toro riding mower to fit through 30-inch rows. While I was able to control broadleaf weeds reasonably well, the grasses growing between the rows recovered very quickly and still competed heavily with the crop. I also hit so many rocks that I am not sure how that poor little lawn mower survived it!

The researchers managing the robots had experienced similar issues. Flying rocks were noted as a major safety hazard as well as causing significant wear to the blades. The team also has experienced numerous mechanical problems with the robot track system, requiring robots to be rescued from the field at times. They also noted that programming routes for the robots required a lot more work than anticipated.

While the reliability of these machines will likely improve over time, I’m not sure how much utility they will have on larger dairy operations. A farm the size of Miner Institute, for instance, would require a fleet of twenty or more robots to cover all of the corn acreage in a week’s time. That’s not even considering the time it would take to shuttle robots and batteries out to remote field locations.

I see this technology as best suited for use on small, organic dairies that still want to grow corn for silage. Especially ones with close fields that don’t have too many stones. When used in combination with a roller-crimped cover crop, I think this strategy might work very well as a “clean up” pass that could take out most of the broadleaf weeds that grow through the cover crop residue. Tractor-mounted row mowers are also available and may be a more economical option in the long run.

So, unless you want a weeding robot for the coolness factor, I would prioritize robotic feeders, pushers, and milking machines if you are looking to automate your farm operation.

— Allen Wilder

wilder@whminer.com