- Assessing the impact of machinery and the potential benefits of switching to controlled-traffic farming (CTF) can be a daunting task
- The CTF calculator allows growers to assess current and future machinery purchases to better understand the area trafficked
- The calculator can also estimate the impact of compaction on yield
Matching machinery for controlled-traffic farming (CTF) can be a daunting prospect for growers looking to make the switch.
Every farm is unique and the path to adoption of CTF can often involve significant changes to machinery affecting every operation on the farm. The number of different options and calculations may seem overwhelming, but help is at hand with the CTF calculator (found at: www.ctfcalculator.org).
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The CTF calculator is a web-based tool designed to help farmers and their consultants make CTF machinery investment decisions.
The calculator is based on the 'Trackman' wheel track calculator, originally developed in 1998 by Peter Walsh and Troy Jensen at the then Queensland Department of Primary Industries - and Geoff Newall, from the University of Southern Queensland. It was first made available online by Precision Agriculture in 2015.
Now, an enhanced version of the CTF calculator is available following development by the Western Australian Department of Primary Industries and Regional Development, with GRDC investment.
The CTF calculator provides valuable information on the area trafficked to help growers assess the impact and potential benefits of matching machinery in their system.
The calculator estimates the percentage area of the paddock that is trafficked by different machinery combinations and the estimated benefit of managing compaction through the adoption of CTF.
Users can enter their current machinery combinations into the calculator for each farming operation - for example, seeding tractor, air cart and bar or spreading tractor and spreader.
The calculator generates the percentage area that is trafficked for each farming operation and an overall combined percentage for all operations over the season.
Inputs required include tyre size, track gauge (tyre centre-to-centre dimension) and operating width.
Users can compare different options for matching up track gauges to reduce wheeling percentage by entering the details of proposed new and modified machinery.
For example, the calculator shows that a typical machinery fleet that is not matched (see Figure 1, top) traffics 48.6 per cent of the paddock, while a fully matched CTF system on a three-metre track gauge (see Figure 1, bottom) traffics only 13.2 per cent.
Calculating the cost
The benefit of matching can be calculated, as the model has compaction penalties for different soil types that are combined with the grower's own grain price and yield.
In the example in Figure 1, the estimated benefit of adopting a fully matched CTF system in sand with a compaction penalty of 30 per cent is $47 per hectare (based on a grain price of $220 and average yield of two tonnes per hectare). In a red loam with a compaction penalty of 10 per cent the benefit is $15/ha.
Growers can use the calculator to evaluate how changing machinery specifications would alter the percentage of the paddock trafficked.
For example, if a CTF system running a 36.6m sprayer, 12.2m header and 18.3m seeder is upgraded to a 55m sprayer and 18.3m header - which matches 3:1 - the trafficked area is reduced from 18 per cent to 13 per cent.
Assessing the impact of matching machinery and the potential benefits of CTF provides vital information for machinery investment decisions.
It is usually not economically feasible to convert to fully matching machinery in one or two seasons.
Changing machinery in line with an existing farm machinery investment plan is a good approach to developing a fully matched CTF system without incurring the massive expenditure of a rapid change.
Many successful CTF farmers have taken eight to 10 years to develop a fully matched CTF system. But the key to success over any time frame is to develop a machinery plan to achieve the CTF system you want and then stick to it, even if it takes longer than planned.
GRDC Research Code DAW00243