Soil and Plant Nutrition

Which of the following items is a primary ingredient of humus? 

• Dead plant material
• Rocks from Earth's crust
• Minerals
• Metals

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.

When plants, animals, and other organisms die, they break down and become part of the soil. What is this part of the soil called?

• sand
• silt
• clay
• humus

Which of the following is the largest particle in soil?

• sand
• silt
• humus
• clay

What effect do plans roots have on a rock?

• They hold it together
• They made it turn to sand
• They cause it to undergo chemical changes
• They break it apart

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

What exactly is bedrock?

• Any organic rock or mineral
• Rock that has not been weathered
• Rock that lies underneath water
• Especially soft rock

If a plant is placed in a pot that contains sandy soil, what will happen when the plant is watered?

• The soil will hold the water. 
• The water will puddle on top of the soil. 
• The water will drain through the soil quickly.
• The water will immediately dry up.

Which type of soil does water have difficulty moving through easily?

• Sandy
• Humus
• Loam
• Clay

Horizon A, or topsoil, is found above Horizon B or subsoil. 

• True
• False