Snapshot

• Growers: Michael and Larissa Pfitzner; Drew and Danielle Pfitzner
• Farm name: Hill End
• Farm size: 3300 hectares
• Location: Griffith, NSW
• Soil type: Red sandy loam
• Average annual rainfall: 400 millimetres
• Soil pH: 4.6 to 5.2 (calcium chloride)
• Enterprise: Continuous cropping
• Crops: wheat, barley, canola, lupins, vetch and lentils

Viewing a large-scale, on-farm cropping trial in a high-resolution satellite image convinced New South Wales grower Michael Pfitzner it was time to convert his grain business to controlled-traffic farming (CTF).

Michael was initially looking at an aerial image of the trial to find ways to reduce his fertiliser costs during a period of high fertiliser prices in 2008. What he saw was almost 50 per cent of the paddock covered in wheel tracks.

“We weren't originally looking at getting involved in CTF," he says.

"At the time, fertiliser prices were going through the roof; it was towards the end of a number of years of drought and dry conditions, and we just thought that we couldn't farm like this any longer, so we were looking at alternative fertiliser options in this trial."

The image revealed a corresponding link between wheel tracks and plant biomass.

"We were surprised to see so much of the paddock covered in wheel tracks because we had been practising no-till farming for many years, and the paddock had just one pass of the seeder and harvester, while the sprayer used a separate set of wheel tracks," he says.

Compelling image

After seeing the satellite image, Michael was convinced the answer to improved yields on his property would be to reduce machinery traffic across the paddock.

Drew Pfitzner sowing wheat during May using an NDF disc seeder on his family's controlled-traffic farm. Photo: Michael Pfitzner

Extrapolated data from measurements taken from one paddock confirmed his belief, with yield results translating into a $152 per hectare difference in net return between random trafficked and trafficked zones.

"Even though this is data taken from my own measurements, it highlights there can be a big difference in profitability in dry years and, if you assume the same result could be achieved over the whole farm, then the benefit in profitability can be quite large," Michael says.

"For this particular paddock, we estimated we achieved $20,000 extra profit, so the journey for us to a complete controlled-traffic system pays for itself over and over again every year."

While this data comes from Michael's own measurements, researchers agree the economic benefits are significant under a CTF system.

Bindi Isbister, a Western Australian Department of Primary Industries and Regional Development (DPIRD) researcher and Australian Controlled Traffic Farming Association (ACTFA) board member, says research has measured compaction penalties on crop yields ranging from two to 40 per cent, depending on soil type, with the penalty much higher in sandy soils than loams.

Ms Isbister says economic modelling estimates a 51 to 67 per cent increase in profit using CTF for a mixed farming enterprise of variable soil types in the WA wheatbelt.

"To my knowledge, this modelling has not been applied on a national scale, however we know anecdotally that CTF is a very profitable addition to any broadacre business," she says.

"Increasing profit comes from higher crop yields, better grain quality and increased fuel and fertiliser efficiency."

She says it is difficult to accurately quantify the complete economic benefits of long-term CTF given the flow-on effects, which create significant opportunities throughout the farming system.

Making the change

Unlike many grain businesses starting on the CTF journey, the change to a 12-metre/3m system happened relatively quickly for the Pfitzners.

"After we made the decision in 2008, we upgraded our seeding equipment to replace our 52-foot (15.85m) Flexi-Coil air drill," Michael says.

"We were looking at doing this anyway and I had already put down a deposit on a tyned machine, but I changed our order to a 12m disc machine because I thought it would allow us to travel across the paddock more efficiently than a 60-foot (18.29m) tyned machine."

The family's harvester fronts were upgraded to 40 feet (12.2m) wide, which fitted perfectly into the system, and the air cart and chaser bin were both on 3m-width wheel tracks, so the only remaining major piece of machinery to change was the sprayer.

"To save costs, we decided to build our own self-propelled sprayer to fit the system, which has worked well and is still in use," Michael says.

Early challenges

Finding tyres suitable for the new system was an early challenge, with duals on the tractor changed to singles on a 3m system. But after experiencing some power hop on those singles, the Pfitzners changed again to a tracked tractor.

"We now even have tracks on the harvester and, in those wet years, it means we can still traffic paddocks without damaging tramlines when the going gets wet," Michael says.

They have also changed their "pizza cutter" tyres on the sprayer, which damaged the tramlines in the early years, to larger 650-millimetre tyres.

"We haven't had to renovate tramlines anywhere near as much since we have gone to tracked machines and changed the sprayer tyres," Michael says.

System benefits

While moving to CTF has lifted profits for the Pfitzners, they have noted numerous other benefits from making the switch, -some unexpected.

"Our farm has become an easy trial and experimental zone because everything is matched," Michael says.

"We can easily trial different seed, fertiliser and lime rates on different soil types, and it's incredibly simple to get hold of that real data off our own farm and turn it into a gross margin figure."

The Pfitzners run numerous trials each year and over time have managed to understand the role of nitrogen in their sandier soils.

"These sandy rises were under-performing every year, in both dry and wet years, only yielding about 1.5 tonnes per hectare at best, and there was always moisture left over for the weeds to grow in summer," Michael says.

"Since we are now confident in our data, we have managed to lift some of these poorer-performing areas with variable fertiliser applications to being as good as, or better than, other areas, now yielding up to 5t/ha in patches because we have been able to manage the data easily and implement agronomic changes."

Improved weed control has been a major outcome of the move to CTF, with the Pfitzners installing a chaff deck on their harvester to place their chaff and weed-seeds onto their wheel tracks at harvest.

The wheel tracks are not cropped, so a build-up of chaff placed there eventually rots the weed-seeds over time.

Michael has designed and built a shielded sprayer to kill weeds in the chaff line if seasonal moisture levels are not enough to mulch and rot the weed seeds.

"Some ryegrass still germinates, but the visual difference of weeds in the paddock compared to what we saw before implementing CTF has been significant," he says.

As a direct result, the Pfitzners make considerable savings on herbicides throughout the year.

Reduced dust

The other big positive is reduced dust after driving on the wheel tracks, which makes spraying easier and reduces any dust tie-up with glyphosate or paraquat on the wheel tracks.

"Since the tramlines have chaff on them right throughout the year, we don't have the dust problems, particularly during summer spraying, that we had before implementing CTF," Michael says.

He says CTF has also improved paddock trafficability, particularly in wet conditions.

"We aren't messing up the paddocks any more and the tramlines are hard enough now for all vehicles to get over the paddock at any time of the year," he says.

Engineer at work

CTF pioneer Dr Jeff Tullberg, who is also an ACTFA board member, says while broad-scale adoption of CTF principles in grain enterprises is still relatively low, the idea is not new.

Dr Tullberg became interested in the concept of reducing machinery compaction in soils during the 1970s and 1980s when, as an agricultural engineer, he studied the efficiency of traction.

"These were the days when tillage was king and I was struck by the amount of power that disappears between tractors and draught implements," he says.

"Tractors rarely get much more than half their advertised power through to a chisel plough or seeder, and much of that lost power goes into compacting the soil."

Dr Tullberg says his research began with an interest in machinery fuel consumption, but quickly moved into the areas of machinery impact on soil, rainfall infiltration and crop yield.

"Large-scale adoption took off in central Queensland in the mid-1990s and then we saw it used in Victoria and the high-rainfall regions of WA with the concept of raised beds," he says.

GRDC's Farm Practices Survey shows CTF adoption has increased from 15 per cent of Australia's cropped areas to 29.3 per cent by 2016.

However, Dr Tullberg says this national average conceals large regional variations, with 60 per cent adoption rates in central Queensland and falling to less than six per cent in the Victorian and South Australian Mallee region.

More information: Michael Pfitzner, Fiz001@bigpond.com; Dr Jeff Tullberg, jtullb@bigpond.net.au