Soil Formation

Which layer of soil contains lots of roots and minerals for growing plants?

• Topsoil

• Humus

• Subsoil

• Bedrock

Soils form in layers, or horizons, that collectively make up the soil profile. Which horizon would contain the greatest humus content?

• W

• X

• Y

• Z

What layer of soil is in the middle?

• topsoil

• bedrock

• minerals

• subsoil

Among the following which is not a factor responsible for soil formation

• Climate

• Vegetation

• Parent rock

• Technology

Which on of the following is not a factor of soil formation?

• Time

• Structure of soil

• Biotic objects/

  matter

What are the four soil components?

• Sand, rock, humus, air

• Rock, humus, air, water

• Rock, humus, roots, water

• Rock, humus, animals, plants

Granite has only recently been exposed at a location on Earth’s surface. How will this most likely affect the soil that will eventually form at this location?

• The soil will have a thick layer of humus in the A horizon.

• The soil will contain many of the same minerals as the granite has.

• The soil will consist of thin horizons compared to other types of soils.

• The soil will be made of mostly rock material instead of organic matter.

What is humus?

• soil

• organic matter

• loam

• minerals

What is another name for horizon B in a soil profile?

• litter

• topsoil

• subsoil

• bedrock

Earthworms, moles and other animals help soil formation by:

• Breaking rock down

• Mixing and loosening soil by burrowing 

• Draining the water from soil

• Eating soil