2,000 pairs of underwear were buried across Switzerland to test the soil

A pair of cotton pants is not usually considered scientific equipment. Yet across Switzerland, thousands of them spent weeks underground as part of an unusual experiment into the condition of the soil beneath people’s feet.More than 1,000 volunteers took part, burying underwear and teabags at sites ranging from private gardens and farmland to grasslands and lawns. The idea was simple: let soil organisms do what they naturally do, then measure what was left behind. Cotton provides plenty for microbes and other organisms to break down, making the fabric a surprisingly useful indicator of biological activity underground.The experiment has now helped researchers develop what they call the Underpants Index, a straightforward way of comparing decomposition and getting a sense of soil health.How soil organisms reveal the hidden health of the ground beneath our feetSoil may look relatively still from above, but it is anything but lifeless. It contains huge communities of bacteria, fungi, insects, worms and other organisms, all involved in processes that shape the ground around them. Those organisms help break down dead material and return nutrients to the soil. The speed at which that happ...