GR 7 COMPOSITION OF SOIL

Which of the following is the largest mineral particle found in soil?

• silt

• sand

• dirt

• peat

Which of the following is the largest mineral particle found in soil?

• silt

• sand

• dirt

• peat

Which part of topsoil contains decayed plant and animal matter?

• silt

• sand

• humus

• clay

Which activity will most likely increase soil fertility?

• Worms are removed from the soil.

• A tree dies and decays.

• Plastic is buried in the ground.

• A tree is cut for lumber.

Read the passage about earthworms.

EARTHWORMS: Earthworms are very important for producing healthy, mature soil. Worms speed up humus

production by eating decaying material. In fact, worms are put into compost piles to help make natural fertilizer for crops. Worms leave holes and tracks in the soil that are

filled with water when it rains. Worms loosen

the top layer of soil making it ideal for thriving

plants.

How do earthworms help create organic material

for healthy soil?

• Worms eat decaying material and break it into

  smaller pieces.

• Worms dry out the soil by drinking the water in

  layers.

• Worms break up rocks into smaller pieces.

• Worms help with chemical weathering.

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

• clay
• sand
• silt
• mud

Layers of soil are also known as:

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

What is humus?

• soil
• organic matter
• loam
• minerals

Soil formation begins with the weathering of 

• litter.
• bedrock.
• the A horizon.
• humus.

Which of the following orders sediment particle size from smallest to largest?

• silt, sand, clay
• sand, silt, clay
• clay, sand, silt
• clay, silt, sand