GoKawiilA thousand people voluntarily buried their cotton underpants for two months—not to keep the Underpants Gnomes from stealing them, but as part of a citizen science project to map out soil health in 25 countries around the world. The results of this unique experiment were reported in a new paper published in the journal Plants People Planet.
“Our results show that how soil is managed can significantly affect both soil life and soil quality,” said co-author Marcel van der Heijden, an agroecologist at the University of Zurich. “Healthy, biologically active soil is crucial for fertility, nutrient cycling and many other ecosystem services.”
Soil health is critical for agriculture and, by extension, food security, not to mention a healthy global ecosystem, but it has been declining worldwide, per the authors. One key indicator of soil health is decomposition rates of complex organic matter, breaking down stuff like leaves, wood, even cadavers into simpler organic and inorganic compounds, releasing C0 2 and nutrients in the process. There have been relatively few large-scale national decomposition studies involving different land use types, although smaller studies have shown that how humans use a site can significantly affect the soil’s biological diversity.
Commercially available teabags are a common material used to measure decomposition rates, known as the “teabag index” (TBI). However, Van der Heijden and colleagues felt the teabag index could be improved upon, given that it requires careful handling and specific tools, like a fine-scale balance. They opted for a more playful approach to illustrate soil composition.
Prior research had shown that cotton strips could also be used to assess decomposition, so why not engage in a bit of citizen science and ask volunteers to bury cotton underpants for a couple of months, then dig them up and record the results? That’s exactly what the authors did in a national project they dubbed “Proof by Underpants.”