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—Ross McKenzie

“You would likely only be adding an ounce or two of N per acre by injecting tractor exhaust into the soil and there is no phosphorus or

potassium in tractor exhaust.”

bourhood of $40,000 to $50,000. This is a very significant investment and likely would never pay for itself on the basis of just reduced greenhouse gas emissions and resulting carbon offset credits.

However, Lewis claims the real advantage of capturing and injecting the exhaust is the second component: the Bio-Agtive Emissions Method (BAEM). This is the management system Lewis created which Lewis says works in conjunction with the BAET and enables growers to use the tractor exhaust to replace most if not all of the fertilizer used in cereal and oilseed production. “It takes 18 tonnes of natural gas to make one tonne of fertilizer. And the emission from making fertilizer and the losses from fertilizer gassing off due to poor application and over-fertilization are much more damaging greenhouse gases than CO2.”

BAEM costs $15,000 for initial setup and then there is an annual technology use fee of $1,500. Growers need both the mechanical system and the technology to be able to reduce fertilizer usage and to participate in his carbon exchange platform.


Many soil and plant scientists question Lewis’s idea that exhaust from the tractor can replace fertilizer. Ross McKenzie, agronomy research scientist with Alberta Agriculture in Lethbridge, says only a minuscule amount of nitrogen is added to the soil from injecting tractor exhaust and most of this is volatile nitrous oxide. “You would likely only be adding an ounce or two of N per acre by injecting tractor exhaust into the soil and there is no phosphorus or potassium in tractor exhaust,” he says.

McKenzie also questions the wisdom of investing $50,000 and more in equipment and technology that has not yet been scientifically proven to work. He also questions a grower risking his primary source of revenue by no longer fertilizing. When asked about the success, some growers claim to have been using this system for three and four years without fertilizing and not seeing a significant yield drop. McKenzie wonders if these growers may not have simply built up fertility levels over years of good management and now their crops are being sustained by drawing down stored soil nutrients.

Lewis counters such arguments by stressing his system is not feeding the plants the way fertilizer does but rather he is “priming the seed and waking up the soil microbes which have the natural capability to provide all the nutrients plants need.”

Lewis says artificial fertilizers actually stop the soil bacteria that naturally fix nitrogen and the soil fungus that makes phosphorus available for the plant. By no longer fertilizing, bacteria and fungus colonies once again thrive and feed the plant.

Lewis claims this enhanced biological interaction can be viewed and measured in fields where his technology is being used. He says root mass is increased, soil respiration is increased, and soils are not as compacted. Lewis claims there are even biological changes in the plant. “The leaf becomes more positively charged which enables the plant to increase uptake of CO2 from the atmosphere.”


For the past three cropping seasons, Dustin Williams of Souris, Man., has injected the tractor exhaust into the soil using a modified Bio-Agtive system supplied by Darrel Carlisle, a farmer from Carroll, Man. Williams says Carlisle has injected the tractor exhaust on his own farm since 2006 and is a licensed dealer of the Bio-Agtive system.

The system Williams is using does not mix the exhaust with the seed, but rather injects the exhaust through the fertilizer openers on

his 50-foot SeedMaster drill. Over the past three years, Williams has varied the rate of N when injecting the exhaust. “The trials with no nutrients have not worked at all,” he says. “However there is definitely a credit in terms of N achieved by injecting exhaust into the soil.”

Williams has found he can reduce the amount of nitrogen fertilizer by about 30 per cent with the system he is using without any decrease in yields. Since soil testing reveals no decrease in organic matter in the soils in spite of decreased N application, Williams believes the injection of exhaust is boosting productivity of his soils.

“Definitely more work and research needs to be done on injection of exhaust into the soil but farmers should not write off this technology at first sight because it does provide a nitrogen credit,” says Williams.

Since 2005, Lewis has convinced about 150 farmers in North America, Europe, and Australia to purchase the equipment and technology. He is working with Jill Clapperton of EarthSpirit Land Resource Consulting, Montana, to determine how the exhaust actually does what it does in the soil. This research is partially funded by the National Research Council of Canada.

After two years of field trials, Clapperton has seen no detrimental effect on the soil from injection of tractor exhaust. Clapperton also has found the effect of exhaust on plant growth has been neutral or positive when compared to conventionally fertilized plots and significantly

better than plots which received no fertilizer or exhaust. “There is definitely a tendency for the plant grown with Lewis’s system to have more growth than the unfertilized control,” she says.

Clapperton believes exhaust stimulates soil micro-organisms, which then provide the nutrients a plant needs. “Soil organisms have the potential to provide much of the nutrients needed by plants. Most growers are likely using more fertilizer than is needed, but we really don’t know how much fertilizer is actually needed to augment the nutrients that can be supplied naturally. Farmers need to reduce the amount of fertilizer used and we need to think about how we can use fertilizer more appropriately. It is likely that even with this technology a certain amount of fertilizer will still be needed. But first, we need to find out what compounds in the exhaust are stimulating soil organisms, how much of the exhaust gets into the ground, and if the use of biodiesel further enhances this technology.”

Lewis says economics is what drives change on farm. And he is offering farmers a package that he claims will enable them to greatly reduce the fertilizer requirements and pay them an average $50 per acre for salable carbon credits. But before investing the $50,000 or so in the equipment and technology, remember, the equipment and Lewis’s theory has yet to be fully tested and proven. And his claims of the number and value of carbon credits used by the crop have not been verified by any of the standards organizations that monitor the carbon economy.

Lewis counters that zero tillage was once a radical idea that many people questioned the wisdom of and now it is the preferred seeding system. He has the same hope for his system.

So Lewis continues to market his equipment and technology, largely through word of mouth and the Internet, to farmers. He continues to seek funding from the provincial and federal governments to pay for research he continues to do on his system and theories. He continues to travel to Europe, Australia, and China to try to find support for his theories offshore. And he really hopes to convince governments and carbon regulators that his methodology for calculating carbon offsets is valid. Such a recognition would enable him to openly market his credits to all consumers and industry rather than simply offering them online to environmentalists.

If you are interested in further information on Lewis’s Bio-Agtive system, go to

Gerald Pilger farms near Ohaton, Alta.



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