Front

What is the bottom layer of a soil profile called?

Back

Bedrock.

Front

What initiates the process of soil formation?

Back

Weathering of bedrock.

Front

What is soil composed of?

Back

Weathered rocks and minerals, dead plants and animals, air and water.

Front

How is topsoil primarily held in place?

Back

Plants and their roots.

Front

What is the source of clay, silt, and sand?

Back

Bedrock.

Front

What is the top layer of soil called?

Back

Topsoil.

Front

What is humus?

Back

Decomposed organic matter in soil.

Front

What role do earthworms play in soil?

Back

They aerate the soil and help decompose organic matter.

Front

What is the A horizon in soil?

Back

The top layer of soil rich in organic material.

Front

What is soil erosion?

Back

The removal of the top layer of soil by wind or water.