Western Australia
September 22, 2014
Preliminary frost research on cereals is underway to better understand how farm management practices influence this potentially devastating weather event.
While there have been few incidences of severe frost recorded in Western Australia to mid-September, mild frost in early August did impact on crops in the far eastern wheatbelt.
However, a frost event caused considerable damage to cereal crops in South Australia, Victoria and New South Wales.
The Department of Agriculture and Food WA is leading several large scale frost trials, as part of the Grains Research and Development Corporation’s National Frost Initiative Management program.
The project aims to scientifically explore grower observations about how stubble, soil inversion, crop canopy and grazing influences frost severity, duration and damage.
DAFWA Research officer Ben Biddulph (pictured) said the first two years of the research would provide the foundations for future research into different wheat and barley responses to frost.
“This is an experimental approach to get some good quality data about what management practices influence frost and to what extent,” Dr Biddulph said.
“Once we get a better understanding, this knowledge can then be integrated into recommending and refining these practises.”
Precision agriculture trials have been sown in the Central, upper Great Southern and Lakes regions of WA to examine the influence of different stubble management practices on frost.
These large scale plots are part of a national network of trials that include the mid-north and Riverlands of South Australia, the Victorian Mallee and Wimmera and the central west slopes, plains and Riverina in New South Wales.
Dr Biddulph said the stubble work would build on previous research, which found that stubble retention increased the severity of frost.
“These trials will examine whether there is a different frost response at different rates of stubble retention,” he said.
“It will also examine the influence of different stubble reduction treatments, such as burning, raking and harvesting low with full stubble retention.
“We’re not looking at varieties specifically in this project, rather general management responses to frost.”
Another component of the research will investigate frost responses to soil inversion, by way of mould board ploughs and rotary spaders.
Dr Biddulph said anecdotal information had shown some reduction in frost risk by changing the soil profile, depending on the soil type.
“There have been observations that bringing heavier or darker coloured soils, like clay or gravel, to the surface reduces the frost risk, while the opposite can happen when lighter textured soil types,” he said.
“This research seeks to validate this observation and determine why this happens – whether it is because the heavier soils hold more moisture that better radiates heat; or the soil colour; or something else completely.”
Trials at Newdegate and Kondinin in WA, at Condobolin, Wagga Wagga and Parkes in NSW, and at Hopetoun in Victoria will also investigate the influence of crop canopy architecture on frost.
Skip rows have been sown to create different band widths of crop canopies, sown at various nitrogen and seeding rates, to evaluate the impact of frost on different biomasses.
“Information to date suggests a reduction in crop canopy closure also reduces frost severity,” Dr Biddulph said.
“By getting a better understanding of this phenomenon other related issues can then be addressed, including plant types, as well as weed, pest and disease control and an economic analysis of the yield trade off.”
Another complementary trial at Wickepin is also assessing the role of grazing to delay flowering and exposure to frost.
“Grazing is one of the few things that growers can do once the crop is sown to address the frost risk so the outcomes from this research will be very useful,” Dr Biddulph said.
The partners in the project include the Living Farm group, the University of Adelaide, NSW Department of Primary Industries, ConsultAg, the Facey Group, the WA No-Tillage Farmers Association and the Birchip Cropping Group.
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