What is Soil?

Animals contribute to soil formation through decomposition of organic material.

True

Which of the following is a way that climate affects soil formation?

all of the above

How does soil become enriched during soil formation?

by decaying organisms

Soil is a mixture of _______.

solids, liquids, and gases

Which of the following is defined as combinations of soil particles that vary in size and shape?

Aggregates

Which of the following factors does not affect soil formation?

None of the above

Where does the organic material in soil originate?

decomposing plant and animal matter

What causes soils and their horizons to differ?

All of the above

Which layer of soil is least likely to be penetrated by plant roots?

C (parent rock)

Explain how climate affects soil formation.

Climate affects soil formation by determining the rate of weathering and erosion. Warmer temperatures and increased rainfall increase the rate of weathering, contributing more mineral material for soil formation. Climate also determines the types of organisms that are in a given area. These organisms contribute to the type of soil formed.

Soil is not directly important to animal life.

False

The rate of soil formation cannot be increased.

False

How does organic material enter soil?

Organic material is incorporated into soil as plant and animal matter decomposes.

Which of the following is the designation for bedrock?

R

Which of the following soil particle types is the largest?

Sand

Explain how soil is important to animal life.

Soil is important to animal life for a variety of reasons. Soil helps recycle organic material by housing decomposers. That organic material can then be used by plants. Soil directly benefits animals by providing a number of them with a habitat. Soil provides nutrients for plants, which in turn provide nutrients for animals that consume them.

Explain how the rate of soil formation can be accelerated.

The rate of soil formation can be accelerated by an increase in the weathering of rocks that contribute to the mineral makeup of soil. Topsoil can be increased through the increase of available organic material. Erosion can also lead to an increase in available parent material for soil formation. Even though soil formation can be accelerated, it still takes time for soil to form.

Explain what contributes to topsoil formation and how topsoil is important to plant growth.

Topsoil has the greatest concentration of organic matter and soil life, which makes it rich in nutrients required by plant life to thrive. Areas that have a high turnover rate of organic material will have a deeper layer of topsoil.

Soil horizons are defined by physical features.

True

Which of the following is not a component of soil?

none of the above