Soil science critical to food production in a climate challenged future

September 15, 2021

Australian farming is backed by a century of soil science critical to our capability to support food production in a climate challenged future. 

Image: Soil CRC Project Leader, Professor Terry Rose and PhD Student Cameron Copeland, Southern Cross University. Supplied.

Dr Michael Crawford gets a strong sense of a soil just by touching it. 

“When you pick it up, a healthy soil crumbles in your hand; it feels moist; it’s got a certain kind of smell,” he explains. 

But he says it’s thanks to a long — around 100 year — history of Australian soil science that soils can be assessed not just with senses, but with objective measures too. Crawford is CEO of the Cooperative Research Centre for High Performance Soils, or Soil CRC.

“Australia typically ranks in the top five globally in soil science output every year — most of the fundamental research comes from universities, but CSIRO and state governments contribute significantly too,” says Crawford. 

“We’re able to monitor soil chemistry, and markers of physical condition and biology, which viewed together give a measure of soil health.” 

Funded for a period of 10 years, the $167 million Soil CRC commenced operations in 2017. Eight Australian universities are major partners, along with the NSW Department of Primary Industries (DPI), the South Australian Grain Industry Trust and New Zealand’s Manaaki Whenua Landcare Research. 

“The Soil CRC aims to increase agricultural productivity and profitability through connecting the latest in university soil science with industry and farmers,” Crawford says.

Soils are estimated to directly contribute around $63 billion each year to Australia’s economy through agricultural production alone. Soils’ value increases to $930 billion a year when biodiversity and carbon storage are factored in as economic assets.    

Multidisciplinary approach to soil

Historically, Australia’s strengths in soil research tended to align with institutions that had agricultural science capabilities. Now the range of universities involved is much broader, incorporating basic soil science, agronomy, data, analytics, engineering as it relates to sensors, and social sciences such as economics, marketing and business.  

Crawford says the regional location and diverse expertise of university partners means the very latest in soil knowledge can be efficiently translated into action on the ground. 

The University of Newcastle’s Dr Liang Wang is a specialist in sensors for environmental monitoring, and leads a project aimed at creating affordable and rapid field-based soil tests.

“We’re applying sensing technologies to develop lab-on-a-chip technology for real time analysis of soil,” Wang says. 

The chips will measure dissolved organic carbon in soil, nutrients such as nitrate, phosphorus and potassium, and bioactivity linked with bacteria and fungi.

“We want farmers to be able to prepare a simple solution of their soil mixed with water, put a drop in the chip, and then instantly read the carbon or other nutrient concentration,” explains Wang. 

“We hope this capability will allow farmers to collect soil data in a cost-effective, simple way, and help them make decisions – things like what crop to plant, or how much fertiliser to apply.” 

The importance of organic carbon

Dr Lukas Van Zwieten works at the interface of soil science and agricultural practice. A University of Sydney graduate, he is a Soil CRC program leader, a researcher in NSW DPI, and a farmer himself. 

Van Zwieten says although inorganic carbon does exist in soils in mineral form, it’s organic carbon — found in decaying plant matter, soil organisms and microbes — that is vital for healthy soil. 

“The more organic carbon in soil, the better the cycling of nutrients,” he says. “This means your plants are more likely to grow better, you’ll be less reliant on continual fertiliser application, and healthier soil microbes will lessen the chance of plant disease.” 

“Also, you’ll have improved water-holding capacity, better soil structure and more aeration — together all those things improve resilience of the system and drive agricultural productivity,” says Van Zwieten. 

Murdoch University’s Associate Professor Frances Hoyle has a deep understanding of challenges faced by farmers in managing soil organic carbon.  She is the former WA lead for the ​National Soil Carbon Program, and was a communicator in the federal Carbon Farming Futures program. 

Recognising the broader drivers of climate and localised environment, Hoyle likens managing soil carbon to running an active working bank account.

“You make some withdrawals as you support food production systems, but you should make deposits over time too — things like retaining organic residues on land, optimising biomass production, minimising soil disturbance or keeping crop stubble in the ground all help,” she explains.

Hoyle is one of the Directors of SoilsWest, a body that translates fundamental discoveries in soil science and plant nutrition for applied agriculture and growth of farming businesses. SoilsWest started in 2016 as a partnership between the University of Western Australia (UWA) and the WA Department of Primary Industries and Regional Development (DPIRD). 

It’s now centred at Murdoch University, and continues to build collaborations and partners across Murdoch, DPIRD, UWA, Curtin University and CSIRO to support growers find ways to better manage soils.

“SoilsWest aims to enhance productivity and secure our food futures,” Hoyle says. 

How soil responds to stressors

Griffith University’s Dr Mehran Rashti is interested in soil resilience. 

“In Australian conditions, soils are confronted with drought, seasonal changes, compaction, extremes of acidity and alkalinity, and residues from herbicides and pesticides,” Rashti says. 

“While a soil can be healthy in the sense that it delivers good productivity in a single year, a resilient soil will deliver productivity over a long time frame, and despite exposure to stressors.” 

Mehran’s research aims to delineate how organic carbon delivers resilience in different types of soils, in various parts of Australia and for a range of crops. 

“I’m using a range of analytical approaches to distinguish between different forms of organic carbon to better understand their role in regulating soil resilience to stressors,” Rashti says.

Healthy soils are an asset Australia’s soil science capacity is set to grow. As part of a new National Soil Strategy, the May 2021 Budget launched the National Soil Science Challenge, making available new funding to address priority gaps in Australian soils science through a competitive grants program of $20.9 million over four years. 

“Australian soils aren’t easy — they have their challenges and their constraints,” says Crawford.  “Being able to understand and manage our soils into the future is fundamentally important.”

Written by Sarah Keenihan

First published in Australian University Science, issue 6

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