Soil Unit- Horticulture

Which type of soil has the lowest rate of permeability?

• sand

• silt

• clay

• loam

Soil is made of ---

• weathered rocks and minerals.

• dead plants and animals.

• air and water.

• all of the above

Which layer of soil is on the bottom of a soil profile?

• topsoil

• subsoil

• bedrock

• humus

Which of the following is NOT one of the three layers of soil?

• topsoil

• undersoil

• subsoil

• bedrock

Humus is ---

• the dead parts of plants and animals in soil.

• A food we eat with pretzels.

• The tiny particles inside of soil.

• The roots that come off of a plant and live in soil.

What is the layer of soil just below the topsoil?

• bedrock

• subsoil

• topsoil

• humus

Horizontal layers of soil are called ---

• Soil profiles

• Soil horizons

The texture of soil depends mainly on ---

• the types of plants that grow in the soil.

• the size of the particles in the soil.

• the color of the soil.

• the number of worms in the soil.

Why is topsoil darker than all other levels of soil?

• It contains all the darker colored minerals.

• It contains volcanic rock.

• It contains more organic matter.

• It contains bits of burned trees.

Where does most of the water go when it rains?

• In the ocean

• In the rivers

• In the gutters

• It absorbs into the soil.