Soil is the loose, living layer of earth that covers most land on our planet. It's made of tiny pieces of broken-down rock mixed with decayed plants and animals, water, air, and billions of microscopic organisms. When you dig in a garden or scoop up a handful of dirt, you're holding soil.

Soil takes hundreds or even thousands of years to form. Rain, wind, and ice break rocks into smaller and smaller pieces. Dead leaves, fallen trees, and other organic matter decay and mix in. Earthworms, insects, and bacteria work constantly, breaking everything down further and mixing it together. Good soil feels crumbly and rich, not hard or sandy.

Plants need soil to grow because it anchors their roots and provides water and nutrients. The word topsoil refers to the uppermost layer, which is usually the darkest and most fertile. Farmers care deeply about their soil because healthy soil means strong crops.

The word can also be a verb meaning to make something dirty. If you soil your clothes while gardening, you've gotten them muddy or stained. When someone talks about their native soil, they mean their homeland: the actual ground of the country where they were born.