Soil surface in Pargas, Lounais-Suomi.

Soil is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Earth's body of soil, called the pedosphere, has four important functions:

as a medium for plant growth as a means of water storage, supply and purification as a modifier of Earth's atmosphere as a habitat for organisms All of these functions, in their turn, modify the soil and its properties.1