What Is Soil?

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.

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

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.

by decaying organisms

C (parent rock)

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.

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.

R

none of the above

all of the above

All of the above

decomposing plant and animal matter

True

True

None of the above

solids, liquids, and gases

False

False

Sand

Aggregates