Definition Soil

The unconsolidated mineral or organic material on the immediate surface of the earth that serves as a natural medium for the growth of land plants.

The unconsolidated mineral or organic matter on the surface of the earth that has been subjected to and shows effects of genetic and environmental factors of: climate (including water and temperature effects), and macro- and microorganisms, conditioned by relief, acting on parent material over a period of time.

So then, what is dirt?

Dirt is what gets on our clothes or under our fingernails. It is soil that is out of place in our world – whether tracked inside by shoes or on our clothes. Dirt is also soil that has lost the characteristics that give it the ability to support life – it is dead. Soil performs many critical functions in almost any ecosystem.

There are seven general roles that soils play:

Soils serve as media for growth of all kinds of plants.

Soils modify the atmosphere by emitting and absorbing gases (carbon dioxide, methane, water vapor, and the like) and dust.

Soils provide habitat for animals that live in the soil (such as groundhogs and mice) to organisms(such as bacteria and fungi), that account for most of the living things on Earth.

Soils absorb, hold, release, alter, and purify most of the water in terrestrial systems.

Soils process recycled nutrients, including carbon, so that living things can use them over and over again.

Soils serve as engineering media for construction of foundations, roadbeds, dams and buildings, and preserve or destroy artifacts of human endeavors.

Soils act as a living filter to clean water before it moves into an aquifer.

There are many soil properties that help us describe and manage soils.

Some of the important physical properties are described below.

Land and People
Soil Texture