Evidence from research in Queensland, West Australia and South Australia demonstrates that controlled traffic will increase yield by 10-15 per cent, while reducing fuel use and tractor size by 20-50 per cent, and improving soil structure. According to University of Queensland researcher Jeff Tullberg, farmers who have adopted controlled traffic confirm that the same thing happens in practice. Increase in cropping opportunities is equally important for northern region farmers.
Dr Tuilberg says controlled traffic challenges some conventional ideas.
Some examples of half truths that slow the adoption of controlled traffic, and Dr Tullberg's responses:
- 80 kpa or 12 psi is a very low tyre pressure — No. Ask someone who's been run over by a tractor!
- unplanted strips are a bad practice: they reduce yield and encourage weeds — No, Tyre-width strips have a negligible effect on yield, and allow more timely weed control
- soil structural damage is caused by tillage — Yes, but wheeling often causes more damage, further down the soil profile, where it's difficult to fix.
- zero-tillage will, fix all these problems anyway — Not when wheeling effects last two years, and we wheel 50 per cent of crop area even in zero-tillage production.
- controlled traffic means replacing all your equipment — No. Most controlled-traffic farmers started by lifting the planter tines behind their tractor wheels, and adjusting boom spray width to two or three times planter width. Bigger changes occur later, as part of normal equipment replacement