Grower snapshot, Robin Schaefer and John Gladigau, 'Bulla Burra'
- Location: Loxton, South Australia
- Soil types: sandy rises, loams, heavy constrained flats and small areas of shallow stone
- Average annual rainfall: 275 millimetres
- Growing-season rainfall: 175mm
- Property size: 8000 hectares
- Crops: wheat, barley, canola, lentils, chickpeas, field peas, lupins and vetch
- CTF system: 1:2:3 CTF ratio, with 12.2m-wide seeders, harvesters and roller, 36.6m-wide sprayers and spreader either 24.4m or 36.6m wide.
The key message that comes from the controlled-traffic farming (CTF) experiences of South Australian growers Robin Schaefer and John Gladigau is that the system needs to be one part of a whole-of-farm approach - to improve crop root growth, increase crop access to water and nutrition and, consequently, to boost yield potential.
Along the way they also report improved vehicle trafficability, particularly on sands, which has made operations such as deep ripping more efficient and improved the consistency of inter-row sowing.
Robin and John's jointly run business, 'Bulla Burra', is an 8000-hectare continuous cropping enterprise near Loxton on a landscape of sandy rises, loams, shallow stone and heavy constrained flats.
About a decade ago, wheat made up 80 per cent of the program. But this has been reduced to 55 to 65 per cent as barley, canola, lentils, chickpeas, field peas, lupins and vetch now give shape to a much more diversified regime. All of the cropping is based on no-till and variable-rate applications.
It is important to have a clear goal when planning the move to controlled-traffic farming - it might take 10 years, but you'll get there eventually.
'Bulla Burra' began its foray into CTF in 2012 with the alignment of machine wheel tracks and the purchase of a tractor with track tyres.
The main aim was to alleviate compaction, particularly on sands, and give crops better access to soil moisture and use of summer rainfall.
Robin and John say the main issue was managing logistics and efficiencies during the time it took to gradually introduce new or modified machinery to suit CTF.
Accurate guidance was also an issue, as a real-time kinematic base station network was not then available.
Today, new John Deere receivers and differential correctors mean the property doesn't need repeaters and they have access to three-centimetre guidance accuracy.
There have been ongoing wind erosion issues on wheel tracks running over sandy rises and these are repaired as soon as erosion begins to appear, to avoid the problem escalating.
CTF has improved the consistency of inter-row sowing through paddocks being sown west or north on even run lines and east or south on odd run lines.
This means the seeder can more easily keep between the previous stubble lines while still compensating for the slight variances in machine-row alignment and the tendency to crab sideways on hillsides.
The machinery modifications to convert to CTF are based on a 1:2:3 CTF ratio, with 12.2-metre seeders, harvesters and roller, 36.6m sprayers, and spreader either 24.4m or 36.6m wide.
All equipment has three-metre wide wheel tracks. Robin estimates that the CTF machinery footprint sits at about 12 per cent of the total paddock area for most operations.
Overall, Robin says, CTF has helped increase machinery and operational efficiencies and there is a clear difference in the friability of the soil and resilience of crops. This is particularly noticeable in seasons with a dry finish.
"We notice that the plants growing on wheel tracks die off very quickly, which is a good indication that minimising machinery compaction on the rest of the paddock is beneficial," he says.
All up, the changes to their farming system, including no-till, crop diversity, variable rate, deep ripping and CTF, have combined to lift the crop water use efficiency.
In the past three years they have been able to harvest crops in the sort of low rainfall that would have led to crop failure twenty years ago.
The plants growing on wheel tracks die off very quickly, which is a good indication that minimising machinery compaction on the rest of the paddock is beneficial.
Robin says one of the key lessons for growers considering CTF, or any major change to the farming system, is to have a clear goal and plan that is based on a long-term objective.
"It might take 10 years, but you will get there eventually," he says.
More information: Robin Schaefer, 0417 877 578, John Gladigau, 0428 874 315, firstname.lastname@example.org