Soil-3rd Grade

What is bedrock?

• The movement of weathered rock.
• The hardest and lowest layer of soil.
• Loose material that covers much of Earth's surface.

What is humus?

• The decayed remains of plants and animals.
• The loose material that covers much of Earth's surface.
• Something you eat! 

The more humus there is in the soil, the __________________ it is.

• saltier and greener
• lighter and unhealthier
• darker and richer

Which layer of soil do plants usually grow in?

• topsoil
• subsoil
• bedrock

What type of soil is made from a mixture of sand, silt, and clay?

• sand
• silt
• clay
• loam

Soils can be all different colors.

• True
• False

When soil is being formed, the first step is: 

• weathering of rock
• mixing with humus
• mixing with air and water

Which layer of soil is weathered into small pieces to form soil?

• bedrock
• subsoil
• topsoil

Soil takes many ________ to form.

• days
• months
• years

Soil formation is considered a _________________ change to Earth's surface.

• fast 
• slow
• no