Farmers keen to swap fertiliser for emissions

Haidee VandenbergheCountryman

Growing crops from nothing but tractor fumes might sound like a pipedream, but the Johnson family at Burakin are giving it a go.

Canadian inventor Gary Lewis designed a system that takes the exhaust fumes from a tractor, cools them and then injects them into the soil through the air seeder.

The exhaust fumes travel through a six-inch stainless steel pipe and then down a flexi tube to the air seeder. The fumes are cooled by a fan, after which they are dispersed evenly through hoses into the ground.

The emissions are said to boost soil carbon and nitrogen levels, thereby encouraging microbes that consume greenhouse gases and convert them into plant nutrients. Nutrients contained in the soil are unlocked and root systems are said to become more vigorous.

By using the system, Mr Lewis claims fertiliser needs, soil acidity and carbon dioxide emissions can be reduced.

While the system has drawn scepticism from some quarters, and some claim the supporting science is lacking, Mr Lewis’ Bio-Agtive Emissions Technology has a growing number of fans throughout Australia.

It’s the first year that Brett Johnson, who farms with his parents Trevor and Helen and fiance Sarah Burrage, has used the system.

The family began looking at the system as a way to reduce fertiliser costs.

Mr Johnson said although they had taken a cautious approach, they had already saved $70,000 in fertiliser costs — more than the cost of the $60,000 system.

“Normally, we’d put 60kg of DAP down the tube with the wheat and 40kg to 60kg of Flexi-N after seeding, ” he said.

“We still spray Flexi-N on all the crops, but we’ve cut out DAP. Instead, we’ve spread 60kg of single phosphate with trace elements just as a safeguard.

“If this doesn’t work, then our land hasn’t gone backwards at all — it’s still kept all its levels up where it should be.”

It’s a system that sounds almost too good to be true, but Mr Johnson said they had invested with their eyes wide open.

“If it works, that’s fantastic, but if it doesn’t we’ll be going back to fertiliser — it’s that simple, ” he said. “We looked at this for about three years and we weren’t too sure about it. We spoke to farmers from around Australia about it and they had nothing negative to say.

“One farmer in South Australia is now in his fourth year. He’s bitten the bullet and isn’t using any fertiliser at all. He couldn’t be happier with it, but we wanted to do our own trials and feel it out for ourselves.”

The family has several trials in this year to determine the efficacy of the system, and Mr Johnson said they would continue the trials as long as it took to prove whether sequestering the emissions worked.

“We’ve done one plot of just single phosphate spread out and the next plot has got single phosphate plus the exhaust system, ” he said.

“The next plot has got single phosphate, the exhaust and that will have some Flexi-N on it afterwards.”

There is also a plot with DAP and Flexi-N — the family’s usual crop treatment — another using just the exhaust system and a control plot that has had no fertiliser or exhaust application.

It’s early days, but Mr Johnson said after being seeded a month ago there were no visible differences between the plots. But the jury is out until the plots have been soil and tissue tested and the yields have been recorded.

Nevertheless, Mr Johnson said there were impressive results on several patches of acidic soil.

The family has attempted to seed the areas for the past four or five years without success. But this year is another story.

“We’ve put oats and some serradella into it, seeded dry in late April and we can’t believe it — there’s crops growing on it, ” Mr Johnson said.

He’s not sure whether it’s the exhaust system or getting the seed depth right, thanks to a new seeding module.

“We were having issues before with soil throw, ” he said. “You could get your seed depth right behind a tyne, but the next tyne passes through next to it throws dirt on top of your row and your seed depth is double what it should be.

“Now we’ve got Manutec press wheels independent of the tynes and it’s working incredibly well.”

The young farmer said even if the exhaust system did not hold true to all its claims, it still might come in handy in a climate where farmers may have to be accountable for their emissions.

The system comes with a monitor that shows the fuel to air ratio, as well as the heat of the fumes. It logs the amount of carbon passing through the tubes, but Mr Johnson said in the near future the monitor would be able to calculate the amount of carbon sequestered.

“This was more about achieving efficiency and trying to make farming profitable again, but if the emissions trading system comes in, then with this (exhaust) system, we’ll probably be onto a winner, ” he said.

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