soils

What is the layer of soil just below the topsoil?

• soil
• subsoil
• topsoil
• terrace farming

When plants, animals, and other organisms die, they break down and become part of the soil. What is this part of the soil called?

• sand
• silt
• clay
• humus

What is the layer of soil that contains humus, leaf litter, and other organic matter?

• O - Organic
• A - Topsoil
• B - Subsoil
• R - Bedrock

Which layer is the bottom of the soil profile?

• C - Partially Weathered Parent Material
• D - Separated rock
• R - Bedrock
• A - Topsoil

Layers of soil are also known as:

• Soil Profiles
• Soil Horizons
• Soil sheets
• Soil cores

Layers of soil are also known as:

• Soil Profiles
• Soil Horizons
• Soil sheets
• Soil cores

In which layer of the soil profile contains the MOST humus?

• Layer 1 (A)
• Layer 2 (B)
• Layer 3 (C)
• Layer 4 (R)

Soil is made of

• weathered rocks and minerals
• dead plants and animals
• air and water
• all of the above

An organism, especially a soil bacterium, fungus, or invertebrate, that breaks down organic material is a...

• Decomposer
• Burrower
• Humus source

Soil formation begins with the weathering of_______.

• Humas
• Subsoil
• Litter
• Rock