Piece of evidence: Underpants

Soil enables human life on earth, as it is crucial to almost every aspect of life on land. However, little is known about the creatures that live and thrive in it. This joint venture of the University of Zurich and the Swiss federal research institute Agroscope aimed at investigating soil life together with private gardeners, farmers and other interested citizens with the help of underpants. Underpants? That’s right: underpants.

Participants buried cotton underpants all over Switzerland, dig them up after a while, took a photograph and dried them. The more degraded the underpants, the more active the soil life and – the healthier the soil. This experiment should show, whether the decomposition of cotton fabric by soil organisms is a suitable indicator for soil life activity.

Photographs and background information were uploaded to an online platform and were made visible on an interactive map. In addition, simple do-it-yourself tests were presented, so participants could examine and understand soils on their own.

Underpants and a soil samples were sent to the Agroscope-Lab, where, the grade of decomposition of the underpants was determined and the soil sample was analysed for soil biodiversity, biological activity and soil quality. Interested citizens were also involved in this analytical process.

The aim of the project was to shine a spotlight on the essential but rather unknown and fascinating universe below our feet. The public got the opportunity to experience that soil is more than a surface to walk on, more than dirt sticking to our white sneakers and more than substrate to pot our plants into.

Soils accommodate billions of bacteria, fungi, insects, worms and other creatures. Their abundance and activity are central features of healthy soils. The more diverse the soil community, the better the soil can function. For soils, functioning means to be able to produce food and raw materials, filter water and protect against natural hazards.

With this project, we wanted to get an overview of the biological activity in Swiss soils and find out under which conditions soil organisms thrive. However, we did not only wish to collect and evaluate data, we also wanted to give back and provided the participants with tools and knowledge to enable them to independently observe their soils in the future. A picture book created as part of the project introduces the key players in soil life and provides interesting background information.

Through the project "Beweisstück Unterhose" (Piece of evidence: Underpants), an indicator for soil life activity was developed together with the Swiss population, thus making the topic of soil quality and soil biodiversity tangible.