Swiss citizens help map soil vitality by burying cotton underwear

In a nationwide Swiss experiment, more than a thousand volunteers buried cotton underwear and tea bags to provide a simple metric of underground biological activity. The initiative, run by the University of Zurich and the federal agricultural research centre Agroscope, followed a uniform protocol that allowed participants to retrieve and document the materials after two months, sending them and accompanying soil samples to a laboratory.

Analysis published in *Plants, People, Planet* produced a detailed map of soil vigor, showing that private gardens host the most active soils, while lawns exhibit the lowest activity; agricultural fields and meadows fall in between. Co-study leader Marcel van der Heijden emphasized that management practices shape soil health, recommending measures like keeping soil covered, applying compost, diversifying rotations and limiting synthetic inputs.

Co-project leader Franz Bender warned that excessively rapid decomposition in near-natural habitats may signal nutrient imbalances. The project also generated one of Switzerland’s most extensive citizen-science soil datasets, with around 240 volunteers listed as co-authors and receiving personalized feedback on their soil’s condition.