What Is Soil?

Soil is not just brown dirt — it is a mixture of amazing things! Soil contains tiny pieces of broken rocks, dead plant and animal parts (called 'organic matter'), water, and air. Yes, there is air in soil! That is why earthworms can breathe underground. The tiny rock pieces come from weathered rocks — wind, water, and ice break big rocks into smaller and smaller pieces over thousands of years until they become soil.