Swiss Citizens Bury Underpants for Soil Health Study

Citizen Science for Soil Health

A unique citizen science initiative in Switzerland engaged 1,000 individuals in burying cotton underpants for two months. This project, dubbed "Proof by Underpants," aimed to map out soil health across 25 countries by observing the decomposition rates of the cotton material. The findings from this experiment have been published in the journal Plants People Planet.

Importance of Soil Quality

Marcel van der Heijden, an agroecologist at the University of Zurich and co-author of the study, stated that soil management significantly impacts both soil life and overall soil quality. Healthy, biologically active soil is crucial for fertility, nutrient cycling, and various other ecosystem services, which are vital for agriculture and global food security. The authors note a worldwide decline in soil health.

Measuring Decomposition Rates

Decomposition rates of complex organic matter serve as a key indicator of soil health. While commercially available teabags are commonly used for this purpose in what is known as the "teabag index" (TBI), researchers sought a simpler method. The teabag index requires careful handling and specific tools, such as a fine-scale balance. Prior research had indicated that cotton strips could also effectively assess decomposition.

The "Proof by Underpants" Approach

To make the assessment more accessible and engaging, the researchers opted for a playful approach using cotton underpants. Volunteers buried the underpants, then retrieved them after two months to record the decomposition. This method allowed for a large-scale national study involving different land use types, providing insights into how human activities affect soil biological diversity.