Soil is a fundamental farm asset that underpins agricultural production and sustainability.
As farm sizes have increased in recent decades, the need for greater efficiency drove growers to invest in larger farms and ever-larger equipment. Growers soon realised that this efficiency was coming at a cost for soil structure.
Soil compaction became particularly evident in the highly responsive clay soils of central Queensland, where controlled-traffic farming (CTF) took off in the 1990s.
The uptake of CTF has spread across Australia and, while it is still more common in Queensland and high-rainfall areas, a growing understanding of compaction - even in sandy soils - is driving adoption across a wider area.
In the early days, getting the system to work was quite a challenge. But CTF has become far more accessible with the advent and widespread uptake of two-centimetre real-time kinematic (RTK) guidance systems for machinery.
Setting up for success
Essentially, CTF divides the paddock into two separate zones.
- The traffic zone is permanent wheel tracks or tramlines for all farm machinery, based on a standardised width (the distance between wheel centres).
- The remainder of the paddock, in between the tracks, is the cropping bed where the soft, uncompacted soil can perform at its best.
The benefits of minimising compaction are well known, starting with maintenance of soil structure and physical properties, which lead to better water infiltration, crop root growth and access to soil moisture and nutrients.
Ultimately, this improves yield and profitability and reduces risk - particularly in very wet or very dry seasons. These are all key priorities for Australian growers and GRDC.
Added benefits include:
- improved trafficability;
- increased longevity of soil amelioration;
- reduced fuel and power requirements; and
- reduced nutrient losses.
As the basis of precision agriculture, CTF enables growers to reduce overlaps or gaps, implement inter-row sowing and spraying and utilise other precision tools - such as variable-rate inputs.
Machinery needs
Implementing CTF on-farm can be a real challenge that takes a lot of planning.
While the cost of changeover may be perceived as a barrier, the actual costs can be quite low.
Most growers buy the required machinery as part of their normal replacement program - taking five to 10 years to end up with a fully matched CTF system.
Manufacturers now offer a suite of CTF-compatible machinery, meaning that matching wheel tracks is easier than ever. Growers need to develop a thorough CTF plan to start the change.
There are still challenges to overcome and, as with any system, CTF growers are continuing to innovate to increase system efficiencies.
We believe that CTF has the potential to play a valuable role across all types of systems and encourage growers to consider how it might help improve the profitability and sustainability of their business.
Research and development
Over the years, GRDC has supported a number of investments to measure the benefits of and promote CTF through research partners and in collaboration with the grower-led peak body, the Australian Controlled Traffic Farming Association (ACTFA).
Growers are often the greatest innovators when it comes to getting the system to work on the ground. CTF has the potential to play a valuable role across all types of systems and growers are encouraged to consider how it might improve the profitability and sustainability of their business.
More information: john.rochecouste@grdc.com.au, stephen.loss@grdc.com.au, rowan.maddern@grdc.com.au