IT’S still a work in progress.
But many South Coast farmers are starting to see rewards for their efforts in ameliorating soil.
It includes clay delving, lime and gypsum applications, along with deep ripping, spading and mulching practices.
And in high rainfall broadacre cropping districts, it is becoming more common to hear about crop yields of five or six tonnes a hectare.
According to Agronomy Focus principal Quenten Knight, getting the right agronomic package could result in a conservative boost of between 10 and 20 per cent on those yield figures.
“There’s certainly an appetite for more research and development in high rainfall areas to find the right agronomic package to grow higher-yielding crops, but it needs grower support and funding,” Mr Knight said.
Perhaps unsurprisingly, as new frontiers are pursued, there remains a lot of naysayers and fence-sitters.
But Mr Knight said leading producers inevitably would provide the economic evidence most farmers wanted before making any decisions.
“We have some leading producers along the South Coast who have been ameliorating their soils for more than 20 years and have been trialling new crops and pastures and have found the economics are working in their favour,” he said.
“Admittedly we’re talking about a low frost-risk environment but I believe there is massive scope for a significant productivity jump along the South Coast.”
Mr Knight and some Esperance growers have travelled to New Zealand and Tasmania over the past 12 months, supported by a Grains Research and Development Corporation grower development grant to observe first hand the agronomy package required to produce high yielding cereal crops.
Part of the agronomic package comes back to management, paying attention to earlier sowing, timing of fungicide applications, assessing longer growing season varieties and perhaps the introduction of plant growth regulators to shorten crops and thicken stems to avoid crop lodging.
“Fungicide application is an important consideration and we learnt that farmers in high-yielding areas of Tasmania and New Zealand have adopted a three to four-spray program during the growing season to keep leaves disease-free,’’ he said.
“In WA the common fungicide application practice is for an in-furrow treatment plus one flag leaf spray, so that’s one of the areas that requires a bit more R&D.”
With earlier time of sowing, Mr Knight said there were seeding opportunities in March and April.
“But the agronomic package would have to include longer growing-season winter varieties to replace out Spring wheats,” he said.
Mr Knight and several Esperance growers have already implemented some of the knowledge gained from New Zealand and Tasmania farmers, observing clear visual responses that will be validated this harvest.
The premise for all of this, of course, is getting soils right – pH balance and structure-forming to allow access to air and moisture.
And the proof of this ‘pudding’ is happening with many of his clients.
An example is Lennoch Park, Neridup (north east of Esperance), owned by James Lewis, who learnt a lot about soil amelioration from his uncle Ross Whittle.
Mr Whittle, who died in 2012, was a keen advocate of deep ripping and clay spreading, a practice continued by Mr Lewis on the nine metre controlled traffic system started more than a decade ago.
In the past three years a farm average of between 3-3.5 tonnes a hectare was considered a good result but this year Mr Lewis is hopeful that might kick up to 5t/ha.
He is hosting deep ripping trials on his property for the Department of Primary Industries and Regional Development but already is convinced of the value of the practice.
And Mr Knight believes it is part of the ‘hyper-yielding’ agronomic package.
“This sort of country often carries too much water in the middle of winter,” he said.
“Deep ripping helps get the moisture and air into the deeper soil profile while allowing plant roots deeper access to moisture during spring and you will often see crops hanging on a lot better in deep ripped country compared with non-ripped where plant roots are shallower and unable to access moisture at depth, leading to plant stress.”
Mr Lewis agrees.
“The crops on our ripped country are hanging on really well and it gives you confidence to increase inputs to boost yields knowing the plant roots can get down to the stored moisture, particularly from summer rains,” he said.
Over the past 10 years, Mr Lewis also has applied between 5-6t/ha of lime on deep ripped paddocks and now has surface soil pH between 6-6.5 with the deeper profile moving from 4.2 to 5.
“This has allowed us to bring barley back into the rotation in these paddocks,” he said.
“Before, it couldn’t handle the compaction and the acidity.”
Surveying another paddock of potential 4t/ha-plus wheat, it used to grow silver grass and it was full of diseases.
“We did a spring claying, then ripped it (600 millimetres) and brought it back into production,” Mr Lewis said.
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According to Mr Knight, attention to improving soil opens up a lot more avenues to start pushing a system.
And this is where soil mapping technology such as EM (electro-magnetics) and radiometrics could become an integral part of the hyper-yielding package.
In fact Mr Knight sees EM and radiometrics being a great asset because of the ability to identify soil constraints limiting yield potential.
“We have the capability of developing deep ripping maps, identifying areas that need claying or delving and variable rate nutrient application maps such as potassium maps,” he said.
“There are a whole multitude of uses for this technology and we can develop a five year plan that can prioritise those jobs and evaluate what will give the bigger return on investment.
