Switzerland soil health study uses cotton decomposition to map microbial activity

Researchers from the Swiss agricultural research institute Agroscope and the University of Zurich have published results from a large-scale citizen science project designed to map soil health across Switzerland.

Initiated in 2021, the study, titled ‘Beweisstück Unterhose’ (Underwear Evidence), involved approximately 1,000 volunteers who buried more than 2,000 pairs of cotton underwear and 12,000 tea bags in various locations, including gardens, meadows, and agricultural fields. The decomposition rate of the cotton served as a proxy for biological activity; higher microbial activity, driven by bacteria and fungi, leads to faster breakdown of the cellulose material.

The findings, published in the journal ‘Plants, People, Planet’, indicate that soil usage was the most significant factor influencing decomposition rates. Specifically, the study found that organic matter decomposed most rapidly in private gardens compared to other land types. This research aims to improve the understanding of microscopic organisms essential for nutrient cycling, fertility, and overall ecosystem services.