For the past two years, SA Arid Lands Landscape Board's Sustainable Agriculture Facilitator Andrea Tschirner has been burying underwear in paddocks as part of an initiative to help spread awareness about soil health in pastoral areas in SA's north.
Along with a range of hands-on soil testing activities with pastoralists, this work has been undertaken as part of the From the Ground Up program that is funded by the Australian Government's Future Drought Fund - an initiative to test and improve soil health.
"The project involved burying 100 per cent cotton underwear in the soil for at least two months to observe the level of decomposition, which indicates microbial activity and overall soil health," Mrs Tschirner said.
She said the project's goal was to collect "high-quality data" by helping pastoralists understand soil science.
"We have focused on pastoral areas from north of Port Augusta all the way up to the Northern Territory and across to Queensland and New South Wales," Mrs Tschirner said.
"A lot of soil science traditionally focuses on agronomy areas, like crop and grain production and viticulture, but we wanted to generate excitement about soils in the rangelands again.
"Given the recent severe national drought, it was the perfect time for people to learn more about soil conservation."
Mrs Tschirner said that formally measuring and monitoring soil biology, requires the refrigeration and freight of soil samples to a testing lab in Adelaide within a very short time period. This is not only expense, but often near impossible from rural locations. From the Ground Up has used methods developed the Australian National University ‘Soil your Undies’ initiative – to trial in low rainfall and arid regions….and it has shown great results!
She said a few years back, the ‘From the Ground Up’ initiative teamed up with the Australian National University, which got Bonds involved to donate cotton underwear for testing.
But why underwear?
"Soils with a healthy mix of bacteria and fungi can break down organic matter like cotton, hence the use of cotton underwear," Mrs Tschirner said.
"We bury pairs of cotton underwear in different areas of a paddock and check on their biodegradation after a few months."
In essence, the faster the underwear decomposes, the healthier the soil is considered to be as it indicates thriving microbial activity and excellent soil health.
"It's all part of the learning we do together with landholders - testing soil pH (pictured above), describing soil texture and profile, measuring rainfall infiltration, soil temperature, and soil biology/health," she said.
Mrs Tschirner said the underwear in the main image above was buried close to each other, but the difference in soil health was incredibly varied, illustrating the positive influence of root growth and plant cover on soil biology.
"The pair that is more degraded was buried under an Acacia shrub and would have decomposed in the more rich and vibrant soil," she said.
“To us it highlights the impact of really good grazing and land management in terms of maintaining vegetative cover to help build soil health.
"We hope people who have attended our case study trips (pictured left) go home and might think about the influence of pasture management on soil health and erosion risk. Having access to soil test results and case study sites helps land managers to review their practices or confirm that what they're doing is on the right track.
To learn more about the work that the South Australian Arid Lands Landscape Board does across SA, visit here.
