Swiss soil health citizen science study

Researchers from the University of Zurich and Agroscope have released findings from a large-scale citizen science project titled ‘Beweisstück Unterhose’ (Proof by Underpants/Underwear Evidence) to assess soil health across Switzerland.

Spanning five years and involving approximately 1,000 volunteers, the study utilized the burial of over 2,000 pairs of organic cotton underwear and 12,000 tea bags or filters at various locations. Because cotton is composed of cellulose, the rate of its decomposition serves as a metric for biological activity from bacteria, fungi, and earthworms. Researchers established an ‘underwear index’ to quantify this microbial activity.

The results, published in the journal ‘Plants, People, Planet’, indicate that decomposition rates vary significantly depending on land use. Private gardens and orchards exhibited the highest levels of soil activity and organic matter, with cotton decomposing more rapidly in these fertile environments. Conversely, manicured lawns and conventional agricultural lands showed lower decomposition rates, suggesting differences in microbial density and soil vitality. The research aims to improve the understanding of microscopic organisms essential for nutrient cycling, fertility, and overall ecosystem services.