A Manitoba farmer is now selling a contraption he says cuts down on pollution from diesel tractors and helps improve the quality of farmland at the same time.

Darrel Carlisle, a grain farmer near Souris, Man., collects the exhaust emitted by his diesel tractor and uses it instead of outside air to move seed and fertilizer in his air seeder, in a system designed to help improve the soil by renewing its carbon and carbon dioxide, reducing the need for fertilizers.

Carlisle began testing units last year in Manitoba; an Alberta partner has been using the system for six years. The pair have launched the operation of about 50 units across Western Canada and the United States, and so far, testing has suggested the system works, Carlisle told CBC News.

"Everything we've seen here so far has been quite positive," he said Tuesday.

"We're growing good crops. Our soil tests, our tissue tests and everything else are holding their own or getting better. We appear not to be depleting anything in the soils right now. Everything's looking quite positive so far."

The system puts about eight kilograms of carbon dioxide into the soil per hectare, which reduces the tractor's emissions by about 95 per cent, Carlisle says, and it doesn't appear to add any toxins.

"Everything coming out of your smokestack is stuff that's naturally in the ground to start with. Basically what your fuel is, is crude oil coming out of the ground in the first place," he said.

"With the equipment we're running or analyzing with, we analyze every nutrient coming out and there's no toxic nutrients we're putting back in the soil."

The equipment is not cheap; each unit costs nearly $50,000. But Carlisle estimates a farmer with 600 hectares could recoup that cost in fertilizer savings in one season.

As yet, the project has not received funding from a federal or provincial government, but Carlisle hopes that will change.

"We've been working on trying to get the [federal] Environmental Farm Plan on board," he said.

"If we could get them on board to help the farmers with their up-front costs to get the system up and running, then we'd all be doing something good for the environment. That's the whole idea of this plan, is my understanding."