Soil is important to all life because it helps support the growth of plants. Soil is made up of water, air, weathered rocks, organic material, and living organisms. We classify soil according to its color, texture, the size of its particles, and the ability it has to absorb water and support plant growth. Dark-colored soil is an indicator of rich organic matter being present. Lighter-colored soil has less organic matter present. We also classify soil according to the size of its particles