Most of us walk over it every day without a second thought—that thin layer of earth beneath our shoes that sustains all terrestrial life. Soil represents one of Earth’s most complex and least understood ecosystems, teeming with billions of organisms in a single handful. This vibrant underground world holds secrets about our planet’s past and keys to our future survival. The complexity of soil begins with its living components. Bacteria, fungi, protozoa, nematodes, and arthropods form intricate food webs that recycle nutrients and create soil structure. Mycorrhizal fungi extend filament networks that connect plant roots, acting as underground communication highways that allow trees to share resources and warnings. Earthworms engineer…