Recycling diesel emissions for farm fertilizer?

by Marian Lyman Kirst

The summer of 2007 was one of the driest and hottest on record in Montana. Fields withered along the state's arid Hi-Line. But in the small, north-central town of Rudyard, one emerald-green cornfield stood out amid the brown. The field was a test plot grown with a technology that only a fed-up farmer could have invented: a system that turns diesel tractor exhaust into plant food.

That farmer is Canadian Gary Lewis, a trained mechanic and the inventor of Bio-Agtive Emissions Technology, a tractor add-on that recycles diesel emissions into fertilizer.

He came up with the idea back in 2001, when despite his careful applications of pricey fertilizer, his timothy hay fields failed to grow. Lewis, who has a wife and five kids, was devastated.

He believed that years of dousing his fields with chemical-heavy fertilizer had made the soil too salty, less biologically active and unable to retain moisture. So he decided to jump off the chemical treadmill and find another way to tend his plants, which on their luxury diets had grown lazy.

Lewis, who looks like an "American Gothic" version of John Elway, has the tenacity of a champion quarterback. He spent the next year poring over plant-science textbooks like Horst Marschner's Mineral Nutrition of Higher Plants. Armed with a new understanding of soil and plant health, Lewis used his automotive skills to implement what he fondly calls his "crazy idea": harnessing the carbon dioxide, nitrogen gas and heavy metals -- zinc, copper, magnesium and iron -- in tractor exhaust and using them as fertilizer.

His invention cools the exhaust, runs it through a metal tubing system, and feeds it into the tractor's air seeder. Those emissions are then injected into the ground along with the seeds. Lewis believes this stimulates soil microbes and beneficial root fungi, whose activity liberates nutrients already in the ground and increases the plants' ability to absorb both nutrients and water.

"My tractor became a living thing, burying all of its energy to feed things in the soil –– bacteria and fungi and micro-invertebrates," he enthuses.

The Bio-Agtive process also coats the seeds with emissions, which Lewis believes protects them against soil pathogens. Some of the minor emissions from diesel engines, such as formaldehyde, are the same chemicals used in protective seed treatments, he says.

More than 100 farmers in the U.S. and Canada have purchased Bio-Agtive through Lewis' company, N/C Quest Inc. But like any innovation that promises revolution, the system has its skeptics. "People thought I was burying poisonous gas in the soil!" says Lewis. Admittedly, diesel emissions are far from healthy for people. Yet Lewis contends they are fine for plants.

To help prove it, he enlisted the support of Montana State University Northern's Bio-Energy Center, which began testing Bio-Agtive on spring wheat crops last year with the help of a Montana Research and Commercialization Board grant. Though preliminary, the results are promising: The center didn't detect any dangerous heavy metals in the grains or tissues of emissions-treated plants, and, after one season of testing, found higher yields and increased soil phosphorous levels in those, compared to fertilized fields. What's more, the acidic condensate associated with the cooled emissions helped reduce the test plots' alkaline soil (common in the arid West) to more neutral levels. The center is also testing Bio-Agtive with biofuels like camelina biodiesel, the use of which could reduce farmers' dependence on both fossil fuels and fertilizer.

Canadian soil ecologist Jill Clapperton has spent the last five years investigating Bio-Agtive's effects on soil, seeds and plants, working both with the Bio-Energy Center and the National Research Council of Canada.

"When a farmer uses Bio-Agtive," says Clapperton, the seeds "become extremely coated with soot and exhaust emissions … they get very, very black." But the coating does not seem to reduce germination rates, as she had suspected it might. She also looked for negative effects on soil health -- respiration, the microbial community -- but found none.

Lewis, she says, may be correct that emissions-coated seeds are better able to fend off potentially pathogenic fungi, but she stresses that more research is required. Clapperton's less sure, however, about Bio-Agtive's potential as a fertilizer. There are clear differences between the control and emissions-treated plots, she says. "But whether (those changes) relate to Gary's theory as he sees it is another question." Montana State University agronomist David Wichman worries Lewis' too-good-to-be-true tech is just that. He did not see yield increases in his research trial of Bio-Agtive on winter wheat, though he acknowledges the testing was limited in scope. He cautions farmers to wait for scientific proof before spending $30,000-$55,000 on a Bio-Agtive system.

Lewis responds that the price is "about the same as one truckload of fertilizer." Indeed, small-grain farmer and Bio-Agtive distributor Craig Henke of Chester, Mont., says the system saves him $50,000 a year in phosphate fertilizer costs. He still applies some nitrogen to his plants but says he has seen a four-fold increase in soil phosphorous levels since he started using Bio-Agtive six years ago.

For Lewis, it's all about helping farm families gain some independence and security.

"When you are addicted to something, it's hard to take the risk to quit. But the best thing with this technology is that, in the gambling game of farming, you are keeping money in your pocket.

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