Broomehill, Western Australia, growers Scott and Lisa Thompson took a decade to move their whole farming operation to a controlled-traffic farming (CTF) system. Scott first toyed with the idea back in 2001 and it was not until seeding 2012 that he had all his machinery matched on permanent wheel tracks.
It may have been a long time in the planning, but Scott believes the steady strategy of gradually turning over his machinery to fit his 12-metre CTF system has been worth the wait, with the benefits now clear on his 4000-hectare property.
For growers in the higher-rainfall zones – Scott’s annual average rainfall is 405 millimetres – moving to a CTF system may appear to be a massive hurdle, especially with the added challenge of a mixed livestock and cropping rotation.
However, Scott says that making it a measured move with a long-term aim to line up all machinery on the same tracks was not daunting, and the strategy fits his business and management style.
Scott began his progression into CTF by matching machinery purchases with his 36m self-propelled sprayer. All machinery is now based on a 3:1 principle, in multiples of 12m, with 25-centimetre row spacings on the seeder bar.
Scott admits he did not have clear goals at the start of the process, but says the benefits and opportunities have now become clear, including improved trafficability in wet paddocks, greater fuel efficiencies, better stubble management and improved moisture retention in the crop rows during the growing season.
Ultimately, though, a steady increase in crop yields since 2012 has been the clear validation for his decision to move to CTF.
“While the CTF system might not be the only contributor to these yield increases, we have seen improvements in the order of eight to 10 per cent over the past five years, so something has certainly changed since we implemented this system,” Scott says.
“Having a controlled-traffic-farming strategy has also allowed me to improve my management, and every year I’m learning to do things a little better.”
One of the most significant opportunities to come from the implementation of CTF on the Thompsons’ property has been their ability to manage weed seeds during harvest.
“I spread straw over the paddock and I put chaff on the tracks using a chaff deck,” Scott says.
He says weeds germinate early in the season on the wheel tracks and he can usually get a good ‘knock’ before seeding.
“There is a portion of seeds that don’t germinate at all, because they have been through a mulching process. Of what’s left, there are higher numbers on the tracks, but not too many to worry about.”
Scott says he has considered a shielded sprayer, which may give him added weed control on the track lines.
“That’s something that I will look at in coming years as I see how the wheel tracks handle the weed burden,” he says.
Scott is now inter-row seeding every second year.
“By doing this my theory is that there will be increased trash flow, and because I’ll have the two furrows, it will allow for more residue,” he says.
“This will increase trash flow at seeding and in the long term I would expect to increase residue cover. I’m hoping to maintain moisture in both furrows.”
He also believes there is a biological advantage to the system: “We don’t seem to have enough science out there to measure what is happening below the surface, and perhaps we don’t have enough respect for what is going on underneath. But I think this system, and the increased residue, is the start of trying to protect the health of the soil and I think I’ll see the benefits of that over time.”
Scott began implementing CTF in a small number of paddocks, and over the past few years has applied the wheel tracks to paddocks as they come out of pasture.
But Scott is the first to admit the new system comes with its challenges, particularly with sheep being a critical part of the business structure.
While he has downsized his flock dramatically in the past three years, from 12,500 Merinos to just 4000 this season, sheep will continue to be part of the rotation, at least for the short to medium term.
“Going forward, the sheep are really just going to be a weed-control tool within a long-term cropping rotation. It’s difficult to stick to CTF with sheep walking all over the lines, and having to drag the sheep feeder across the paddocks,” Scott says. “Over summer, while we graze most paddocks, there is about 10 per cent I don’t graze. By keeping sheep out of those paddocks I keep the weed seeds on the surface. I don’t want the sheep to cultivate those seeds into the soil. They also put tracks through the chaff, and I have noticed water infiltration is much poorer in the following season after too much grazing.”
The change to a CTF system was also a mental shift for his workers and contractors.
“I have to use contractors who fit into my system, particularly spraying and harvesting contractors,” Scott says. “We have to enter and exit a paddock in the one spot, and put field bins in strategic places during harvest. It takes a level of discipline, and for the first couple of years it was difficult. It was a whole new paradigm that we all had to get used to.”
Tackling the myth
WA Department of Primary Industries and Regional Development (DPIRD) officer Bindi Isbister, who works with growers considering a CTF system, says there is a myth that this move can be too expensive.
Bindi says results from a 2016 survey of more than 100 growers, consultants and agronomists looking at soil-compaction management strategies for a WA DPIRD-managed, GRDC-funded soil-compaction project showed only 22 per cent of growers were using CTF – although this was up from 17 per cent recorded in a 2012 survey.
“Growers, agronomists and consultants are saying that incompatible machinery and financial limitations still remain key limitations to the adoption of soil-compaction management, particularly the introduction of CTF,” Bindi says.
“But Scott and Lisa’s strategic approach has demonstrated that, with proper planning, those two limitations can be overcome. Apart from the purchase of some guidance equipment, Scott hasn’t found the outlay any more significant than his normal machinery turnover program.”
Scott believes the opportunities presented by CTF have far outweighed the challenges.
“It’s taken me 10 years to accumulate all that gear for the CTF system, and most growers would turn over their gear in 10 years, so there really isn’t a huge difference in the financial outlay,” he says. “There is also plenty of second-hand machinery out there that will do the job – you don’t have to purchase new.”
Scott says his only regret today is not establishing the wheel tracks in 2001 when he was first thinking about it.
Picture - Scott Thompson, who farms in the higher-rainfall zone of Western Australia’s Great Southern region, has shown that moving to controlled traffic does not need to happen overnight.