Soil Formation

What are the four soil components?

• Sand, rock, humus, air
• Rock, humus, air, water
• Rock, humus, roots, water
• Rock, humus, animals, plants

Which factors are primarily responsible for decomposition of organic materials in soil?

• Animal action and plant action
• Animal action and fungus action
• Fungus action and microorganisms
• Microorganisms and animal action

Decayed organic matter is...

• Hummus
• Humus
• Himalayas
• Hummers

Humus is important because...

• It contains toxic waste
• It contains acids and bases
• It breaks down rocks
• It helps plants grow

What contributes sediment to soil formation?

• Parent rock
• Father rock
• Mother rock
• Large rocks

Does the vertical cross-section of soil in the picture show a soil profile or a soil horizon?

• Soil Profile
• Soil Horizon

Do the horizontal cross sections in the picture show soil profiles or soil horizons?

• Soil Profiles
• Soil Horizons

Which soil horizon is primarily responsible for the soil's fertility?

• The A horizon
• The B horizon
• The C horizon
• The D horizon

In which answer choice are the soil particles arranged in order from LARGEST to SMALLEST?

• Silt, sand, clay
• Silt, clay, sand
• Clay, silt, sand
• Sand, silt, clay

The picture shows desert soil. This forms in dry regions, so which of the following characteristics seems to fit best? The soil is...

• Deep and contains much organic matter
• Deep and contains little organic matter
• Shallow and contains much organic matter
• Shallow and contains little organic matter