New technologies and alternative scientific disciplines are being harnessed in a bid to improve frost monitoring methods and mapping of damage to grain crops following frost events.
UWA PhD student Bonny Stutsel splicing fibre optic cable as part of her work under a new GRDC National Frost Initiative (NFI) project.
“If successful, this could enable growers to customise their own frost management tool kit,” said Nik Callow, of the School of Earth and Environment at The University of Western Australia (UWA).
Dr Callow and PhD students Bonny Stutsel and Mary Murphy, also from UWA’s School of Earth and Environment, are in the WA grainbelt gathering data under a national project managed by CSIRO and funded and coordinated by the Grains Research and Development Corporation (GRDC) National Frost Initiative (NFI).
Several frost events have occurred in the WA grainbelt during recent weeks which have resulted in extensive damage to crops.
Dr Callow said that, traditionally, growers had relied on weather stations to gauge frost severity but there was growing recognition of the benefits of using temperature monitoring equipment within a paddock in frost-prone areas.
“But the key question for growers is: Where should I measure temperature within the crop?” he said.
“Temperatures can vary by as much as 2oC or more between the soil and the plant canopy, and monitoring temperatures well below the canopy may underestimate the likely damage to a crop, particularly during marginal frost events.
“Bonny Stutsel’s PhD is focused on understanding where to monitor temperatures that will give growers data that reflects the temperature that critical parts of plants have been exposed to and the likely damage.”
The team is using fibre optic cable in the field to conduct ‘distributed temperature sensing’ (DTS), a new research technology which allows temperature to be measured every 25cm along many kilometres of the cable, that can be placed in crops.
“While this technology is too cumbersome and costly to use in normal farming systems, the research will allow us to make better recommendations on where to place temperature loggers and whether you need to move them as the plants and canopy grow,” Dr Callow said.
“This will help ensure that low-cost loggers provide realistic data to determine temperature and likely frost damage.”
The other focus of the project is post-frost event detection methods, including the use of Remotely Piloted Aircraft Systems (RPAS), also known as drones or Unmanned Aerial Vehicles (UAVs).
This is investigating whether spectral cameras, which can measure the wavelength of light reflected from plants, or thermal cameras, which can measure plant stress and potentially frost damage, are the best sensors to use in RPAS to map frost damage after an event.
“Mary Murphy’s PhD is looking at how data from the visible and non-visible (infrared) light spectrum generated by spectral cameras may allow frost damage to be assessed well before the visual signs of damage appear,” Dr Callow said.
“Spectral data can be collected from handheld sensors or remote aircraft and the team will evaluate these options and make recommendations on how to most accurately map frost with RPAS.”
Dr Callow said thermal images of crops, also collected from handheld and airborne thermal sensors, could provide an alternative approach to spectral sensing and measure crop stress.
NFI steering committee chairman Peter Roberts said the project included researchers with skillsets not traditionally applied in agriculture, reflecting the multi-disciplinary approach taken by the NFI to address the complex issue of frost.
Mr Roberts, who also chairs the GRDC Western Regional Panel, said the GRDC had long acknowledged the severe implications of frost on crop production and since 1999 had invested about $13.5 million in more than 60 frost-related projects nationally.
“In 2014, GRDC increased investments into frost research through the establishment of the five-year NFI,” he said.
“NFI is a five-year project tackling frost from several angles to deliver growers a combination of genetic, management and environmental solutions to help mitigate risk.
“It is also exploring tools and tactics to help the grains industry better plan for, predict and respond to frost events.”
Information about frost management and links to useful resources are available in the GRDC Paddock Practices article - Tactics to manage spring frost, available via this link.
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