This was the question Department of Primary Industries and Regional Development’s (DPIRD) research officer Bindi Isbister posed to the crowd at the Liebe Women’s Field Day last week.
Ms Isbister has 17 years experience in agricultural research and extension in WA.
This has led to an exciting career working with researchers, agronomists, farmers and ag equipment suppliers across Australia to help farmers apply new technologies such as GPS, yield mapping, controlled traffic management and soil management techniques to increase farm profitability.
At the field day she shared her findings on Controlled Traffic Farming (CTF) and the benefits it has for soil compaction.
Ms Isbister aimed to inform those gathered that new machinery may very well be needed to assist in getting a farm ‘on-track’.
“A CTF farming system is built on permanent wheel tracks where the crop zone and traffic lanes are permanently separated to minimise the impact of machinery-induced soil compaction,” Ms Isbister said.
“It requires matching of the operating widths and wheel tracks for all cropping machinery to reduce the area of the paddock wheeled, therefore investment in machinery or modifying existing equipment is usually required.
“Moving to a fully matched CTF system can be challenging if the farm machinery fleet is not well matched or existing machinery can’t be modified to suit.
“Therefore buying new machinery may be required and the transition to CTF can be done in line with the farm machinery investment plan.”
Ms Isbister said many successful farms have taken eight to 10 years to be fully matched and the process can be expensive.
“Decide where you want to go with CTF in the future and upgrade your machinery over time,” she said.
The main goal of a CTF system is to decrease the wheeling percentage of your paddock.
With a fully matched CTF system wheeling percentage is about 13 per cent of the paddock.
“The aim over time as you start to line up your machinery tracks is to minimise that percentage,” she said.
Ms Isbister said DPIRD and Grains Research and Development Corporation (GRDC) research showed that controlled traffic farming can improve profitability and sustainability.
“CTF increases profit through higher yield, better grain quality and reduced costs,” she said.
“There are environmental benefits, with less nutrient leaching, less water erosion, better infiltration and less greenhouse gas emissions.
“Implementation needs a clear, long-term plan and prioritisation of soil health.”
The department has looked at ways farmers can decrease soil compaction, using deep ripping to remove compaction or ways to manage and minimise compaction which is through CTF.
Ms Isbister said compaction can be machinery induced or natural form, but essentially it slows root growth.
“When there is compaction, plant roots can slow growth to half a centimetre a day, compared to deep ripping trenches where the root can grow up to 1.4cm a day,” she said.
Compaction is caused essentially by machinery and with machinery getting heavier and heavier compaction has become more of an issue.
A fully loaded header can weigh up to 30 tonnes and Ms Isbister said the new John Deere airseeder can weigh up to 48t fully loaded.
The weight of the machine drives how deep the compaction goes. A 5t weight on the axle can put the compaction down to 50cm and 10t or more have a depth of compaction down to 75cm.
Ms Isbister said it’s no new concept that deep ripping removes soil compaction.
“The research has been around for 30 years proving that deep ripping our sandplains benefit crop yield,” she said.
“In sandy soils there is limited natural reduction in compaction.”
Ms Isbister said compaction is getting deeper so instead of having to rip at 30cm they are now having to go down to 50cm.
DPIRD research has found that any ripping on red loam, shallow ripping at less than 45cm deep and deep ripping more than 45cm deep, only shows a seven per cent increase in yield. Compared to pale and yellow sand where you can see a much bigger response with over 60pc yield increase with deep ripping and 30pc yield increase with shallow ripping.
“That’s quite a big negative and reduces return on your deep ripping investment.”