Getting down and dirty in the National Soil Archive

By  Gabrielle Corser 11 September 2024 5 min read

It's the ground beneath our feet and the source of our food. It filters our water and regulates our atmosphere. And getting down and dirty in the garden is said to be nature’s medicine.

But did you know contact with soil can actually release your 'happy hormone'? Contact with a specific soil bacteria, Mycobacterium vaccae, triggers the release of serotonin in our brains.

Soil also underpins nutrients in our food and is the source of life-saving medicines, such as antibiotics. So, it’s vital we monitor its health and ensure its sustainability. Enter the Australian National Soil Archive (ANSA) in Canberra.

We caught up with the manager of the Archive, soil detective Georgia Reed, to learn more.

How did you end up at the Archive?

I’ve always had a keen interest in biological and anthropological collections. My masters’ studies in Archaeological and Evolutionary Science, and Museum and Heritage Studies at Australian National University (ANU) was completed across the road from CSIRO. During that time, I applied to do casual work in the Australian National Insect Collection and the Herbarium. This morphed into the full-time role at the Soil Archive. I’ve been at the Archive since 2023 and am proud to now manage the facility

What does an average day at the Soil Archive look like?

There is no average day at the Archive! There’s a lot of ‘invisible’ work before soil samples can be archived.

Cleaning and curating soil data is a time-consuming process. First, the data is ingested into our database Natsoil. Then, I can begin the process of physical archiving, which includes subsampling for our spectral library. We use specialised equipment to analyse the properties of soil samples, such as mineral content and colour. This information helps us build a comprehensive database that can be used for research and environmental monitoring.

You can also find me in the archive compactus, where I organise and retrieve loaned samples. Or I could be in the lab, processing new submissions and preparing smaller portions of archived samples for loan requests.

The most enjoyable thing about the job is the people I get to work and interact with (especially my team in Soil Monitoring and Information). I get great satisfaction from supporting researchers to accomplish their goals and am fulfilled knowing I’m contributing to Australia’s sustainability goals.

What are some of the challenges of managing the Archive?

Working at ANSA has turned me into a soil data detective!

This is because samples without data cannot be archived. So, I often have to fill the gaps in our knowledge. With samples dating back to as early as the 1920s, it can be tricky to track down all the data. Sometimes, details can be found on old hand-written site cards, in old journal articles, or in notepads. I’ve had projects where the location of soil samples has been recorded as ‘x miles from the local pub’.

The work is very challenging and often fruitless but persisting can be rewarding when old samples are finally archived and made publicly available for reanalysis.

What’s an interesting fact about the Archive?

As of 2024, ANSA holds over 85,000 archived specimens collected from over 23,000 sites across Australia.

These little jars of soil are invaluable time capsules for assessing temporal and spatial changes in soil properties, particularly as new analytical methods are developed. The older specimens from the 1920s to the 1950s were collected prior to the widespread application of pesticides and herbicides, the introduction of microplastics in our environment, and before the start of nuclear testing. So, they represent an important historical record.

Each specimen housed in the collection has an estimated value of around $1,000. You have to consider the cost of field work, sample preparation, chemical, and physical laboratory analysis. I guess you can say that makes us an 85-million-dollar facility.

Exploring new soil science technologies

Peter Wilson is our Manager of National Soil Information.

He says soil science is central to our survival, and the Archive plays a vital role in Australia.

“As a national collection, these 85,000 specimens of soil dating back over a century, give us a window into how soil has changed. They reveal the effects of agriculture, fertiliser use and other land management practices across Australia," Peter says.

“The Archive provides access to soil specimens for new research, and application of new soil science technologies. These include the development of the national soil spectral library and prediction of soil properties through infra-red spectral scanning and modelling.”

Infra-red spectral scanning involves directing infra-red light at soil samples to analyse how it is absorbed and reflected, revealing details like organic carbon content and clay minerals. This data is then used in modelling to predict other soil properties, such as fertility and structure, and to understand how the soil might respond to different environmental conditions.

“Scientists can access soil from right across the country, saving their projects thousands of dollars and significant time as they don’t have to mount expensive field sampling campaigns,” Peter says.

“The Archive also allows integration with systems such as the recently launched Australian National Soil Information System, ANSIS.”

The Australian National Soil Archive support diverse research projects, including:

• mapping soil carbon stocks across Australia using new infrared scanning technology
• studying soil property changes over time by re-analysis of South Australian acid sulfate soils (using specimens from the 1920s)
• examining the potential of soil analysis as a forensic method (by the Australian Federal Police)
• rapid assessment of the distribution of soils with toxic levels of boron
• evaluation of the utility of lead isotopes as tracers by studying Australian dust sources to the Pacific Ocean
• calibrating new soil property measuring instruments.

All archived soil material and data is searchable and publicly accessible.