Soil Your Undies is a unique experiment, used by Australia's cotton farmers to test for soil health. Undies are buried in the soil, and then dug up around six weeks later. The more degraded the undies, the greater level of microbial actvity in the soil - which is one important indicator of soil health.
This experiment also provides a clear, visual reminder of the high level of biodegradability of natural fibres as compared to synthetics like polyester. This video shows a recent example, on cotton farmer Scott Morgan's property near Gunnedah in NSW where he buried both a pair of cotton undies, and a pair of polyester undies. Six weeks later Scott's experiment clearly showed the cotton undies had degraded significantly due to the presence of microbial activity in the soil, but the polyester undies were in perfect condition and could be put on and worn again. The video also includes commentary from Australian cotton's soil health expert, Dr Oliver Knox whi explains the scientific processes of biodegradability.