Soil

No soil, No planet Earth

Soil Terminology

Vocabulary:

Soil Horizon – layers or zones of soil.

Soil profile: different zones or layers starting at the surface and moving vertically down to the bedrock or parent rock

Top soil: two distinct layers/zones – O horizon (organic matter) and A horizon; consists of the first 2 inches of soil.

Soil Terminology

Organic matter - part of the O and A horizon- Living material- Provides nutrients and chemicals to and from the soil

Sub soil - B Horizon- less organic material present

Soil particles – soil is made of 3 main particles – SAND, SILT and CLAY.

Soil Terminology Humus – dead or decaying matter. Located in the O and A horizon

Parent material – A layer of rock which is the beginning of the soil formation process.

Bedrock – a layer of rock which is beneath the soil horizons and a base for the formation of soil.

Weathered material –This is rock that has been broken down by weathering over a long period of time.

Soil Formation -

Factors Parent Material

- Develops from parent material- Undergoes weathering to

change the rock into soil

Time

- Takes time to weathering and change the soil

- Longer time – thicker more developed soil

Climate

- temperature and precipitation- Develops different types of soil

Plants & Animals

- Contains organic matter- Recycling of nutrients

Soil Composition

Soil Formation • https://www.youtube.com/watch

?v=7iyxocIhfu0

Soil Profile The soil profile is the different zones

or layers starting at the surface and moving vertically down to the bedrock or parent rock

Top soil is made up of two distinct layers/zones – O horizon and A horizon.

O horizon: Organic material (plant litter, animals)

A horizon: Mixture of minerals, organic matter and humus

Soil Profile Subsoil contains the following:

B Horizon: Below Top Soil Some biological roots – this is

the lowest point of tree roots Little humus or organic matter Above the C horizon

C horizons:

- Contains mostly weathered material from the bedrock/parent rock- Clear difference between the B

horizon and C horizon- C horizon does not resemble soil- The layer directly above Bedrock.