Frost research to refine management
GroundCover™ Issue: 116
National frost researchNational research is investigating:
- the influence of burning, raking, harvesting low and stubble retention on frost damage in cereals;
- frost responses to soil inversion by way of mouldboard ploughs and rotary spaders;
- the influence of crop canopy architecture on frost; and
- the role of grazing in delaying flowering and exposure to frost.
With frost costing $360 million annually, the GRDC is supporting national research to investiage practical ways growers can mitigate their losses
Frost research on cereals is underway to better understand how farm management can influence this potentially devastating weather event.
While there were few occurrences of severe frost in Western Australia to mid-September 2014, mild frost in early August did affect crops in WA’s eastern wheatbelt.
However, frost caused considerable damage to cereal crops in South Australia, Victoria and New South Wales.
The Department of Agriculture and Food, WA (DAFWA), is leading several large-scale frost trials as part of the GRDC’s National Frost Initiative.
The project aims to explore grower observations about how stubble, soil inversion, crop canopy and grazing influence frost severity, duration and damage.
DAFWA research officer Dr Ben Biddulph says the first two years of research will provide the foundation for future research into different management practices to mitigate frost damage.
“We are developing an experimental approach to collect quality data about what management practices influence frost and to what extent,” Dr Biddulph says.
“Once we improve our understanding, this knowledge can then be integrated into recommending and refining management and assessing other practices.”
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 methods on frost.
These large-scale plots are part of a national network of trials that include the Victorian Mallee and Wimmera and the Central West Slopes, Plains and Riverina regions of New South Wales.
Dr Biddulph says the stubble work will build on previous research, which found that under mild frosts (canopy temperatures of –1ºC to –2ºC) stubble retention increased the severity and duration of frost and caused more frost damage.
“These trials will examine whether there is a different frost response at different rates of stubble retention, crop yield potential and frost severity,” he says.
“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 in wheat and barley.”
Another component of the research will investigate frost responses to soil inversion by way of mouldboard ploughs and rotary spaders.
Dr Biddulph says anecdotal information and previous research on delving had shown some reduction in frost risk by changing the soil profile, depending on the soil type.
“There have been observations that bringing clay or gravel to the surface reduces the frost risk, while the opposite can happen when lighter-textured soil results after soil amelioration,” he says. “This research seeks to validate this observation and determine the likely changes in frost damage that may result.”
Trials at Newdegate and Kondinin in WA, Condobolin, Wagga Wagga and Parkes in NSW, and Hopetoun in Victoria will also investigate the influence of crop canopy architecture on frost.
Crop canopies have been manipulated in a variety of ways, including skip rows to create different bandwidths of crop canopies and various nitrogen and seeding rates to create different biomasses to evaluate their impact on the severity and duration of frost.
“Information to date suggests a reduction in crop canopy closure also reduces frost severity,” Dr Biddulph says.
“By better understanding any potential benefits under frost, other related issues may be addressed, including weed, pest and disease control and an economic analysis of the yield trade-off.”
Other trials at Wickepin, Kellerberrin and Newdegate in WA are assessing the the potential of grazing to delay flowering and exposure to frost.
“Grazing is one of the few things growers can do after the crop is sown to address the frost risk so the outcomes from this research will be very useful,” Dr Biddulph says.
Project partners include Living Farm, the University of Adelaide, the NSW Department of Primary Industries, ConsultAg, the Facey Group, the WA No-Tillage Farmers Association and BCG.
More information:Dr Ben Biddulph
08 9368 3431
GRDC Project Code DAW00234, DAW00241
Region North, South, West