Why Scientists Are Asking People to Bury Their Cotton Underwear

The project, Proof by Underpants, reveals that land management dictates soil health more than almost any other factor. Private gardens, often rich in organic matter, showed the fastest decomposition rates, indicating high levels of microbial and earthworm activity. In contrast, manicured lawns displayed the lowest levels of biological vigor. Agricultural fields and meadows fell between these extremes, according to the study published in Plants, People, Planet.

Marcel van der Heijden, a professor of agroecology at the University of Zurich, notes that soil management practices—such as crop rotation, reduced pesticide use, and the application of compost—directly influence these outcomes. While rapid decomposition generally signals fertile, nutrient-rich soil, researchers warn that it is not universally ideal. In near-natural habitats like forests, excessive decomposition can suggest a nutrient imbalance, potentially caused by over-fertilization.

Beyond the ecological findings, the study stands as a triumph of citizen science. By involving 1,000 participants, researchers gathered data from across the country that would have been impossible to collect through traditional academic fieldwork alone. This effort was so significant that 240 of the volunteers are listed as co-authors on the final research paper, marking a shift in how large-scale environmental datasets are built.