THE idea of using your tractor as a mobile fertiliser factory, by capturing engine exhaust emissions and recycling them into the soil to stimulate plant growth, may seem a little far-fetched.
And with the scientific jury still "out", waiting for peer-reviewed trial results, any thought of adopting such a technique, at best would be considered risky.
Most would consider it madness to plant a crop using no fertilisers.
But Cunderdin farmers Ian and Jodi James don't consider themselves mad, particularly having taken the plunge, building a home-made mobile exhaust emission fertiliser factory and excitedly watching crops bolt out of the ground.
This year is a nil-fertiliser input for the pair, who are firmly convinced they are involved in a proverbial win-win situation by reducing greenhouses gases while sequestering carbon and bolstering gross margins with their cropping and livestock enterprises.
Jodi spent countless hours "surfing the net" to glean information on the subject, while Ian looked at internet pictures and read blogs as he formulated a plan to build his own system.
He couldn't afford to buy and license a commercially-available system made by Canadian farmer Gary Lewis, who developed a mechanical system to deliver tractor exhaust emissions via an air seeder to seeding boots.
Working with a WA-made Phillips Acremaster 401 tractor boasting a 20L V12 Mercedes Benz engine, an eight tonne Fusion air seeder and a John Shearer Trashworker equipped with DBS seeding modules, Ian built an integrated system before the start of this year's seeding season.
The centerpiece is a cylindrical shell and tube heat exchanger mounted on the back of the Acremaster with a port on top of the cylinder to connect a pipe from the engine exhaust manifold and a port at the bottom connecting a hose to the trailing air seeder blower inlet.
The importance of the heat exchanger is to ensure that the exhaust is at an optimum temperature that does not cause detriment to the seed or airseeder hose equipment.
According to Ian, emissions from the engine enter the heat exchanger around 400°C and are cooled to 60°C before it reaches the air seeder fan.
It then is mixed in the air stream that carries the seeds to the boots on the Trashworker with the temperature of the emissions dropping to 30°C by the time it interacts with the soil.
"We didn't use any compound fertiliser or N at all this year," he said. "It was a huge leap of faith and it's like ripping a dummy from your mouth thinking, how can I survive without traditional chemical fertiliser.
"We will monitor plant health using tissue testing and if deficiencies show up in the next couple of months, we can apply biological foliar spray applications, although from the way the plants bolted out of the ground, it doesn't look like we'll be doing any foliar."
Ian is excited at the prospect of growing export hay (the farm's main enterprise) and also improving pastures for a 2200 ewe flock (Prime SAMM-Awassi-cross) which produces for the lamb trade.
"Jodi did all the research on the tractor exhaust emissions including gaining a break down of chemicals in the emissions and travelling to the Carbon Farming Conference in Orange, NSW, last November," Ian said.
"Apart from the obvious nitrous oxides and carbon dioxide, you're looking at trace elements like molybdenum, copper and zinc.
"But the real X factor is the microbiology stimulant effect which can release locked up fertilisers applied years before."
From their research and talking with Gary, Ian and Jodi believe the emissions act as an ameliorant as well as stimulating microbiotic life, which have incredible beneficial effects such as unlocking available phosphorous and calcium and other nutrients and making it available to plants.
"Research has shown that there is no yield penalty from using this method and that levels of available P can increase from eight parts per million (ppm) to 20ppm after two years of wheat sown with emissions and zero fertiliser," Ian said.
"Work that one out.
"We have massive reserves of N, P, K and other minerals on our property because for the last 60 years we have slavishly done what we've been advised to do.
"We've put on way more than we needed and ended up with a toxic soil caused by pumping raw chemical compounds at very high concentrations into the soil.
"It has been piled onto the land and I think using this new system and stimulating the biology I will have plenty of plant-available P for many years to come.
"I've also noticed that the emissions are damp, condensing as it cools, creating a vapour that absorbs the nutrients present in the emissions, delivering it deep into the seed bed, so we're getting a degree of nutrient rich moisture around the seed right from the start and that excites me because I want to get hay crops in early to capitalise on yield potential.
"It was evident how this moisture assisted our late sown lupin crop (sown June 10).
It was up within five days in very dry conditions so we are setting up a far more drought- tolerant crop, since the plant can grow to its natural biological potential without reacting to artificial chemical stimulants and then dying later in the year if things dry out.
"The other aspect of that is with the system we believe we can lessen the frost risk to our crops because our Brix testing of the plants is showing sugar readings around 16, with 14 being good and 18 excellent."
Ian and Jodi say they are recognising many beneficial factors emerging from a system that is compatible with Mother Nature.
"We now classify ourselves as biological farmers," Jodi said. "This year the only addition to the exhaust emissions was our own biological brews for seed dressings.
"And we're seeing benefits not only in improved crop growth but also in the pastures from last year's biological inputs where the sheep obviously are healthier.
"There's a whole dynamic that we can achieve in terms of soil health, crop and pasture health and livestock health that is beneficial to us staying on the land."
On that score, Ian sees lower input cost farming as a huge part of moving into a profitable and sustaining enterprise.
"We've moved from a cost of around $270 a hectare to put the crop in to a figure around $80/ha," he said.
"That means less pressure in lower-yielding years where my break-even is now 50 per cent less, in terms of yield, than what it normally would be.
"And I believe we can bring a lot more of our under-performing land up to scratch so it is no longer a burden to the bottom line."
And if the Federal Government introduces an Emissions Trading Scheme (ETS), Ian and Jodi say they'll be ready.
"We're effectively sequestering carbon with the emissions systems and it is easily measured," Ian said.
"So potentially there could be another income stream for us while we're contributing to depleting greenhouse gases."
