Soil

A mixture of rock particles, decayed organic matte, living organisms, minerals, water, and air is known as

• Bedrock

• Humus

• Soil

• Silt

Soil is 50 percent

• Air and minerals

• Air and organic material

• Air and oxygen

• Air and water

The measure of how well soil supports plant growth is known as

• Fertility

• Permeability

• pH Scale

• porosity

The most important factors in determining the rate of weathering and soil formation are

• Abrasion and acids from plant roots

• Animal actions and oxygen

• Carbon Dioxide and acid rain

• Rock type and climate

The decayed organic matter that gives topsoil its dark color is called

• Clay

• Humus

• Litter

• Silt

Soil Horizon C is also known as

• Bedrock

• Litter Layer

• Subsoil

• Weathered Bedrock

Which statement is true?

The B Horizon...

• Contains as much humus as the R Horizon

• Has less humus than the A Horizon

• Has less humus than the C Horizon

• Has more humus than the A Horizon

Which of these percentages best describes loam

• 40 percent sand, 40 percent silt, and 20 percent clay

• 80 percent clay, 10 percent silt and 10 percent silt

• 90 percent of sand, 10 percent of clay, and 10 percent silt

• 80 percent silt, 10 percent clay, 10 percent of silt

What is the most important role that burrowing animals play in the formation of soil?

• Breaking down organic materials

• Decomposing dead animals

• Holding soil in place

• Mixing air and water into soil

This soil horizon is known as topsoil

• Horizon A

• Horizon B

• Horizon C

• Horizon R