Overview
- The peer-reviewed study published Wednesday used samples from roughly 1,000 Swiss sites to produce a national map of soil biological activity.
- About 1,000 volunteers followed a standardized protocol that buried more than 2,000 pairs of organic cotton underwear and 12,000 tea bags, retrieved items after 30 and 60 days, photographed results, and sent soil samples to the lab.
- Researchers found land use was the strongest predictor of decomposition rates, with private gardens showing the fastest breakdown, lawns the slowest, and farmland and meadows in between.
- The authors proposed an easy-to-understand 'underwear index' that matched results from the established Tea Bag Index and is designed for public outreach and large-scale monitoring.
- The dataset names around 240 citizen co-authors, links decomposition to soil chemistry, temperature and moisture, and offers management advice while warning that very rapid decomposition can signal nutrient oversupply in near‑natural sites.