From Spray to Strike: Could Electricity be the Herbicide of the Future?
Dr Mike Diprose spent a career at Sheffield University researching electrical weed control. No, I don’t mean managing weeds around electrical lines. His research focused on using electrical energy to kill weeds, an approach some now refer to as an “electricide”.
Dr. Diprose’s son Andrew and his team at Rootwave are now commercializing this technology.
“How the technology works is relatively simple” says CEO Andrew Diprose. “You touch a weed and create a circuit. Then you get a flow of electricity. Then the natural resistance of that weed turns the electrical energy to heat, which boils the weed from the inside out from the roots upwards.”
The result is a weed control solution that Rootwave believes is just as effective and affordable as other methods, while being friendlier to the environment and more sustainable long term.
If you’ve ever grown anything, you know weeds are a big challenge. Common solutions to this challenge are herbicides and tillage of the soil. While effective, these come with their own challenges.
Herbicides are becoming increasingly regulated, even in some cases banned. Instances of resistance are making some herbicides less effective over time. Also, herbicides require water which can be in short supply and expensive to transport in some areas.
Recently, Europe considered a ban on glyphosate that ultimately extended the license for five more years, partially due to unavailable alternatives for farmers. At the same time, there have been lawsuits alleging that work-related exposure to certain herbicides has caused cancer. The validity of these claims aside, this regulation and litigation presents large challenges for future herbicide use.
Other weed control measures involve soil disruption through tillage, which can have negative effects such as erosion, carbon emissions, and reduced soil quality.
Rootwave hopes their herbicide-free alternative will help farmers manage all species of weeds without soil disturbance and without breaking the bank for farmers.
Zapping Weeds at Scale
When I first discovered Rootwave, I saw a picture of an individual physically touching every individual weed with an electrical rod. While clearly effective, I could not picture anyone managing weeds this way on a large scale.
As it turns out, that was just an early version of the technology to show it’s effectiveness. What Rootwave is commercializing is a product that, coupled with computer vision, “sees” and “zaps” individual weeds quickly as they are pulled across a field.
“Rather than redevelop the wheel when it came to the vision technology that spots what’s a weed and what’s not, we’ve actually partnered with a company called Stecketee now acquired by Lemken in The Netherlands”, says Diprose. “(They) have a very advanced mechanical weeder that they’ve been selling globally for ten years that uses cameras to spot the weeds in and around row crops. Then they currently hoe (the weeds). By hoeing it, you disturb the soil which comes with all of the disadvantages of soil erosion, carbon emissions, disease, etc. So we are lifting those hoes out of the ground and electrifying them so they zap the weeds as they go through the field. So what we have and are currently testing is a solution that goes through your row crops, has a camera system to spot what to weed, and then zaps them; all without disturbing the soil, and all in an automated fashion pulled behind a tractor.”
Andrew also sees this technology pairing nicely with an autonomous tractor in the future. The energy for the electricity used can be from a generator, alternator, or battery. The current setup utilizes the tractor’s PTO and an alternator using three-phase energy.
Electricity vs Flame
Perhaps you’ve seen the videos of farmers using flames to burn weeds. Andrew points out that Rootwave’s approach is very different. The thermal (flame) approach allows for a lot of collateral damage to the area around the weeds. There is also a lot of energy wasted in the ambient air and ground. Finally, these thermal methods only apply the heat externally and above ground. Rootwave boils the plant from the inside out and from the roots up.
This electricide approach ends up being energy efficient because it only uses energy when it comes into contact with the weed. Andrew says it’s also very safe. Beyond the normal safety protocol that must be followed with any farm equipment, there are minimal additional risks.
Currently the technology is being used in trials in Europe, with plans for global commercialization in 2020. They are primarily treating a weed that’s 1–5 centimeters tall in under 200 milliseconds. Part of the appeal is that it is not limited to any particular species or group of weeds. “Anything green, we can zap” says Andrew. They are working through issues such as how to handle varying crop row spacing and weeds in less managed fields.
Credibility From The Yield Lab
Rootwave is a part of The Yield Lab, a global agtech accelerator that began in the U.S. and has since spread to Europe, Asia, and South America.
The accelerator invested €100,000 into the company, as well as facilitated a nine month program to provide the company with the tools, training, connections, and resources to get to market as fast as possible.
For Andrew, the credibility that The Yield Lab provided was the best part. With such a reputable name behind them, doors began to open more easily as the company nears commercialization.
I was able to chat with Connie Bowen of The Yield Lab on another episode of the podcast, which you can listen to below.
With the help and credibility of The Yield Lab, Andrew and his team hope that a lot more farmers will be electrocuting weeds in the very near future.