At a moment where fertilizer trade concerns are dominating headlines, a revolutionary sourcing alternative has emerged — as if from thin air.
The world has an almost insatiable demand for nitrogen. Crops need it to grow, but although it makes up 78 percent of our atmosphere, plants can’t just pull it in from the air the way they do with oxygen. Instead, they rely on bacteria in the soil to convert it into nitrate, a form they can use; in the case of agriculture, think of fertilizer spread by humans. Leaving aside organic options like cow manure, most farmers use ammonia produced mainly from natural gas using a technique called the Haber-Bosch process, which was invented in 1909.
Haber-Bosch is expensive and energy-intensive, responsible for up to two percent of the world’s annual greenhouse gas emissions. It’s also spurred a global nitrogen pollution crisis; as much as two-thirds of nitrogen fertilizer applied to crops is never used, and the excess escapes into the soil, air, and water, raising the cancer risk in nearby communities and contributing to climate change.
Researchers have been trying to find an alternative way to get nitrogen to plants for decades — turning to everything from microbes to human urine. But so far, these scientific advancements haven’t translated into much practical change for farmers, who for the most part still rely on ammonia (which, granted, is getting greener, but is increasingly vulnerable to global price shocks).
That could soon change with the growth in popularity of a new technology known as plasma activated water, or PAW. Around the U.S., scientists and startups are experimenting with this high-tech solution, which uses electricity to pull nitrogen from the air, mix it with water, and create fertilizer straight on the farm. The concept, on the surface, seems suspiciously rosy — on-demand nitrogen, in a form plants can use, at just the cost of electricity (and the initial price of the machine used to make it). But early adopters have told Offrange that it genuinely works.
“There’s a lot of skepticism from farmers because it seems almost too good to be true,” said Mark Quall, a South Dakota corn and soybean farmer who has been using PAW for the past year. But on his farm, he said, the technology “absolutely worked,” raising the yield of the fields he applied it to, once he was able to work out when and how to spread the nitrogen-infused water effectively.
PAW uses electricity to transform air into plasma — the fourth state of matter (besides gases, solids, and liquids), which typically forms at high temperatures. When the plasma comes into contact with water, it encourages chemical reactions that form nitrates — the type of nitrogen that plants need. Though this process was actually invented in 1903, even before Haber-Bosch, it required so much energy that it never achieved widespread use.
The concept, on the surface, seems suspiciously rosy — on-demand nitrogen, in a form plants can use, at just the cost of electricity.
But in recent years, those energy needs have gone down thanks to the development of “cold plasma” technology, which operates at less than 60 degrees Fahrenheit. It’s also used for medical sterilization and food safety, and over the last decade researchers have worked to develop new ways to apply it for agricultural production.
One of those researchers is Selma Thagard, a chemical engineering professor at Clarkson University who is working on scaling up PAW technology to meet farmers’ needs. Her design uses a spinning disc, which evenly distributes a thin layer of water, exposing a large area to the plasma and maximizing the device’s nitrogen output. The system is designed to operate using similar amounts of energy as common farm equipment, Thagard told Offrange.
“Our vision is distributed fertilizer production,” Thagard said. “Instead of manufacturing fertilizer in large centralized facilities and transporting it long distances, farms could produce nitrogen fertilizer locally using air, water, and renewable electricity.”
Peer-reviewed studies have backed up the idea that PAW can replace nitrogen fertilizer for agriculture, although a lack of uniform standards makes it difficult to apply that conclusion to all products currently on the market. A review of multiple PAW studies by researchers in Ecuador and the U.S. published last year found that aside from its fertilizer properties, PAW “enhances seed germination, plant growth, stress tolerance, and pest resistance.”
Researchers connected to the agricultural industry, such as the Precision Technology Institute, a research farm and educational center based in Illinois, have also conducted field trials with PAW. In a video explaining their results, Jason Webster, PTI’s lead commercial agronomist and director of farm research, stood next to a PAW machine, a white cube covered in metal bars about the size of a large refrigerator.
“There’s a lot of skepticism from farmers because it seems almost too good to be true.“
In the first year of testing, PTI found that applying PAW to commercial corn resulted in almost the same yield while reducing the cost of nitrogen by more than 98 percent. With organic corn, they had to use almost double the amount of nitrogen to achieve the same result, but the cost savings were still substantial.
Although the technology has proven itself in her lab and is now moving on to pilot testing in the field, Thagard said challenges still remain, such as figuring out the optimal nitrogen concentration for agricultural use. Some entrepreneurs, though, are already commercializing PAW. One company called Green Lightning got its start in 2020 when Travis Potter, who had previously worked in the organic food industry, teamed up with Joe Lewis, who patented a cold plasma technology he believed could be used in agriculture.
Green Lightning’s machines use electricity to compel water molecules to hold onto nitrogen — the same process that takes place during a lightning storm — an effect that gave the company its name. The plants then take up the nitrogen when they absorb the water, providing growers with on-demand fertilizer at just the cost of electricity (Green Lightning devices can be plugged into a standard 110-volt power outlet).
The company sells machines of varying sizes to accommodate farms with different acreage; a machine that can supply nitrogen for around 500 acres of cornfields costs $44,000 but saves farmers $60,000 per year in nitrogen costs, according to Matt Vanderhyde, a Michigan corn farmer who uses and sells Green Lightning products. This economic calculus is what got him to seek out the device for his own farm, though environmental concerns like nitrogen pollution also factored in.
“We cared about those things, but really we just wanted to save money,” Vanderhyde said last year on an episode of the Business of Agriculture Podcast.
“Instead of manufacturing fertilizer in large centralized facilities and transporting it long distances, farms could produce nitrogen fertilizer locally using air, water, and renewable electricity.”
Quall’s story echoes Vanderhyde’s. He came across Green Lightning three years ago through a YouTube video, and took some time to research it before deciding to buy a machine and apply it to one field of corn last spring using a drone sprayer. He saw higher yields in that field while reducing his fertilizer costs to under $5 an acre — just the price of electricity. After that, he began selling Green Lightning products through his company, Dakota Ag Solutions, and is now applying PAW to all of his 500 acres.
One of the benefits of the technology, PTI’s Webster said, is that it’s salt-free, allowing farmers to apply it multiple times in a season directly to furrows. (Nitrogen fertilizers that contain salt must be applied several inches away to avoid damaging roots and leaves). Still, it may not be a magic solution. Testing by agricultural company Beck’s Hybrids has found that PAW could only replace some of the nitrogen fertilizer crops needed, not all of it.
Quall said that the trick was knowing that since the nitrogen in PAW already comes in nitrate form, the one that plants use, there’s little point in applying it soon after planting, when corn requires little nitrogen to grow. Instead, he found that it’s most effective when applied three weeks to a month after planting. He and other farmers will keep experimenting with Green Lightning and other PAW products, and they see potential for it to permanently alter the economics of agriculture.
“The main thing is understanding how to utilize this product the way it’s intended to be used, and understanding how different nitrogen forms need to be applied and apply them accordingly,” Quall said. “You think nitrogen is just nitrogen, but it’s not.”
