Pioneering the future of acid sulfate soils

In a career spanning more than 50 years, Fitzpatrick was the first to provide national and international leadership in recognising and establishing the importance, extent and severity of inland acid sulfate soils in Australia and worldwide.

Acid sulfate soils are the nastiest soils in the world because when disturbed, they create significant environmental damage, water contamination and decades of ongoing soil issues.

As the inaugural Director of the University of Adelaide’s Acid Sulfate Soils Centre (ASSC), Fitzpatrick and his team deliver solutions to issues faced by industry and the acid sulfate soils community. His team are working to pioneer acid sulfate soil research to improve environmental science, mineral exploration, forensic science and outcomes for society, highlighted below.

Dry soil – damage in drought

Fitzpatrick and his colleagues have worked to identify, map and predict the formation and distribution of acid sulfate soils in vulnerable inland wetlands prone to droughts. When dry, these soils produce sulfuric acid which can cause severe and long-term damage to ecosystems and infrastructure.

During the Millenium Drought (2007 – 2010), Fitzpatrick utilised his encyclopaedic knowledge of acid sulfate soils and intrepid fieldwork to lead environmental mitigation and recovery work.

He also spearheaded the development and leadership of the Atlas of Australian Acid Sulfate Soils, allowing anyone in Australia to check for these soils before digging via the Australian Soil Resource Information System (ASRIS).

Fitzpatrick’s technical soil classification and regional risk maps have influenced best management principles and new policies for several regulatory agencies.

“Across this work we’ve had many valuable findings. Acid sulfate soils act as critical indicators for predicting environmental deterioration due to drought and climate change. These soils can also act as global indicators for hazard prediction, estimating soil-water and biological responses to environmental changes. Additionally, assessment and monitoring of acid sulfate soils can bridge the gap between disciplines involved in environmental conservation and engineering.” said Fitzpatrick

Mineral exploration

Fitzpatrick and his team have also made significant advancements in understanding inland acid sulfate soils, which led to the publication of the first ever book on inland acid sulfate soils in 2008. They discovered elevated concentrations of elements such as copper, lead and zinc on the hydrous iron-oxide mineral known as schwertmannite and observed irregular lead isotope compositions in acid sulfate soils. This led to successfully introducing a new geochemical sampling medium for deeply buried or blind lead and zinc sulfide orebodies and the discovery of two zinc-lead mineral deposits, one of which was eventually mined.

He has improved classification schemes for acid sulfate soils, including the identification of minerals like schwertmannite and jarosite, which serve as diagnostic criteria for recognising extremely acidic sulfuric material (pH < 4) in Australian and international soil classification systems. These improvements facilitate easier identification of acid sulfate soils.

Forensic support – crime scene soil

At the request of the Australian forensic community in 2003, Fitzpatrick set up the Centre for Australian Forensic Soil Science (CAFSS) after providing critical soil evidence that linked the suspect to the crime scene of a double homicide in Adelaide.

Fitzpatrick has found major satisfaction in utilising his knowledge to assist law enforcement, contributing to over 200 specialised soil forensic investigations.

Collaboration has been essential in solving these complex cases. Fitzpatrick has worked with a diverse group of partners to develop and apply new innovative techniques, methods and strategies to uncover information to solve complex forensic investigations.

For example, his team utilised advanced X-ray diffraction technologies at the Australian Synchrotron to analyse minute particles of acid sulfate soil embedded in pyjama fabric to help solve a 1983 homicide cold case.

The experience gained from conducting case studies, together with specialised research has led Fitzpatrick to develop the national Soil Forensic Investigation User Manual.

“It has been both challenging and rewarding to have successfully presented this complex, new information as evidence to juries and judges in Supreme Court hearings throughout Australia in high-profile criminal cases such as homicide, rape, kidnapping, counter terrorism and major environmental pollution,” Fitzpatrick says.

Soil and society

One of Fitzpatrick’s proudest achievements has been his leadership in developing a specialised Soil Assessment Manual to minimise soil damage to the Australian telecommunication optic fibre cable network caused by shrink-swell soils and soil corrosion. His methodology has been successfully employed by telecommunication engineers, installed across phone and internet networks.

“It has saved millions of dollars,” he says.

Fitzpatrick has made many other contributions across descriptive information on soils, hydrology, and best management practices. These advancements have revolutionised the communication of complex landscape information to land managers and advisors.

“Practical handbooks, guidelines and user-friendly classification systems are already in use in many sectors, including broadacre farming, viticulture, irrigation, commercial afforestation and wildlife conservation,” Fitzpatrick says.

Earlier this year, Fitzpatrick was awarded the Pons Medal in recognition of his outstanding contribution to acid sulfate soil science and practice by the International Union of Soil Sciences (IUSS) at the 9th International Acid Sulfate Soils Conference in Adelaide.

Across his career, he has supervised 21 PhD, 8 MSc and 10 Honours students and won many additional awards for his soils work over the years.

With thanks to The University of Adelaide and CSIRO Mineral Resources.