Humus ET

Humus is a mixture of ___________.

• rocks and sand

• the remains of plants and animals

• water and pebbles

• silt, sand, and clay

A student observed a soil sample and made the following comment:

I think that soil is only made of decomposed

plants and animals.

Is this correct?

• Yes, because all soil is made up of humus, which is made of plant and animal remains.

• No, because there are also some living plants and animals such as worms in the soil.

• No, because soil is made up of remains of plants and animals as well as weathered rocks.

• Yes, because the top layer of soil was created when animal and plant parts decomposed to form humus.