The Soiling Your Undies challenge has people all around Australia burying pairs of undies in the name of research, with citizen scientists tasked to investigate their soil biology.  

While the concept seems bizarre, the state of undies after eight weeks buried in soil holds the key to identifying just exactly how active their soil is, and whether it can be improved.  

Professor at University of New England Dr Oliver Knox says that not just any regular pair of pants is up to the job, with entrants of the challenge being sent pairs of undies made of 100% cotton.  

“The cotton plant has spent a lot of time stitching sugar together to make cellulose, and so by burying the pants, we’re basically saying to the bugs in the soil that they can have the sugar, but you and your buddies are going to have to work to get it,” Dr Knox said.   

If, after eight weeks, all that is left of the undies is elastic and polycotton stitching, it’s a clear indication that the soil life is very active and of high quality.  

“If the pants come back out and look like you could give them a shake and put them straight back on, you’ve got some problems,” he said.  

According to Dr Knox, the undies test was originally implemented in farms as a way of gauging the nutrients in different paddocks and, more often than not, where cropping and vegetation thrived was often reflected in the undies progress in decomposing.  

“In a lot of cases, farmers put one in their paddocks and one in the native vegetation or riparian land nearby and were able to get a feel for how their fields were comparing and behaving in terms of their soil biology,” he said.   

For many discussions, the testing has led to discussions of improving soil and the crops it produces by improving stubble retention or finding organic manures.   

“There’s a whole host of reasons as to why a crop might not be performing. It could be a physical constraint on your soil, or it could be chemical. If it is a chemical issue, then you would see less breakdown in your underpants as well.”  

While the challenge was announced as part of last week’s science week and continues for the eight weeks, the researchers at the forefront of the project were both thrilled and disappointed that the challenge’s popularity depleted their underpants stocks with 300 pairs of undies being sent around Australia. 

“People can definitely still take part, but I think we’ve probably bought every pair of white cotton underpants that our supplier had this year. So, it’s a bring your own pants situation at the moment I’m afraid,” said Dr. Knox.  

After the eight-week challenge has finished, the results from every participant – who are located across Australia, as far as Christmas Island – will capture a snapshot of the health of Australian soils.  

“The big win is just to get people thinking about soil biology. This is an invisible part of our world that we take for granted. A pair of underpants can get people thinking about that soil biology and I think that primes us for having a more sustainable future.”