Grower snapshot, Gavin and Hayley Hill
- Location: Holt Rock, Western Australia
- Property size: 6340 hectares (arable)
- Annual average rainfall: 320 millimetres
- Soil types: 65 per cent heavy - loam (salmon gum/mallee); 35 per cent light - yellow gravel sand (grevillea)
- Soil pH: 5.5 to 7.0 on heavy soils, 4.5 to 6 on light soils
- Enterprise: continuous cropping
- Crops: wheat, barley, oaten hay, canola, lupins, field peas, medic clover
- CTF system: nine-metre multiples on 3m wheel-track centres.
Improving water use efficiency was the main driver in the shift to controlled-traffic farming (CTF) for the Hill family from Holt Rock, Western Australia.
The family established their permanent nine-metre tramlines with 3m wheel-track spacing in 2007.
"We chose this width because we could get away with buying cheaper machinery then," Gavin says.
"Now it complements the hay enterprise, with most passes on the tramlines except the mower and bale stacker."
They are more than happy with the results and have achieved an average water use efficiency of 12 to 14 kilograms of grain per hectare per millimetre of rainfall for cereal crops, even with losses from frost events.
"We can see the difference on-farm in a dry spell, as the headlands will pinch off where traffic is not controlled, while the middle of the paddock won't be showing as much moisture stress," Gavin says.
We can see the difference that controlled traffic makes to our water use efficiency.
Over the years, weed management has been one of the Hill family's biggest challenges.
They trialled chaff decks as a form of harvest weed seed management to deposit weed seeds on the tramlines and left the high-traffic trams bare, but found that they became a source of weeds in this lower-biomass-producing area.
"We weren't getting the weed control we needed, particularly where the headers turned on the headlands," Gavin says.
"This led us back to burning windrows and sowing the tramlines, which has helped with competition.
"In 2019, we invested in weed seed destruction technology for the harvesters. They have performed pretty well so far, with minimal impact on productivity and next to no maintenance."
Their area is prone to devastating frost events and the frequency of these events is a big part of the reason why growing export hay now covers as much as one-third of their land.
Hay production generally gets double-stacked in the rotation plus another break crop, so Gavin can get on top of ryegrass. This means that while the cropping enterprise is full-CTF, all paddocks will see random traffic during this phase.
"The balers and rakes are on the tramlines, but we can't make it work for mowing and bale mustering," Gavin says.
"We recently invested in a bale stacker that can run on the tramlines, but it's inefficient to do so in the lower-yielding years."
It is possible to get triple-deck mowers that would match the tramlines but I'm not willing to sacrifice the faster drying time.
Gavin currently runs a 4.5m Massey Ferguson mower conditioner with double conditioners either side of the tramlines, which has one of the quickest curing times for his hay.
While he says it is possible to get triple-deck mowers that would match his tramlines, he's not willing to sacrifice the faster drying time.
"After controlling traffic for a while, we have found that on some soil types the primary tramlines have sunk up to 100 millimetres, this being mainly caused by the wet years of 2016-17. Seeding depths are shallower in these areas but we haven't seen the need to renovate as yet."
Overall, the Hills are pretty happy with the performance of the controlled-traffic system and believe it has made a difference to their viability in this low-rainfall area.