Introduction to SOIL!

3rd Grade

Why is soil important?

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soil

The loose layer of the Earth’s surface, consisting of rock, mineral particles and decayed organic materials (humus).

humus

• The dark brown or black organic substance made up of decayed plant and animal matter.

Sand

• Small, loose grains of worn or disintegrated rock.

Silt

• Silt soil is finer than sand, but still feels gritty. Silt is commonly found in floodplains and is the soil component that makes mud. Soils with a lot of silt make excellent farm land, but erode easily. This is the soil blown away in dust storms and carried down stream in floods.

Clay

• Clay soil is a soil which has a heavy concentration of clay particles. The high clay content gives clay soil some properties which can make it challenging to work with.

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Topsoil

The upper portion of a soil, usually dark colored and rich inorganic material.

Subsoil

• Also called: undersoil  the layer of soil beneath the surface soil.

Organic Material

• Organic material is material that comes from a living organism or an organism that was once alive. Organic material can decay or is a product of decay.

Inorganic Materials

• Inorganic materials are things that are not living. Some examples are: Rocks, water, and dirt.