Soil profile

Definition

A soil profile is a vertical section of soil from the ground surface downwards to where the soil meets the underlying rock. It reveals different layers or horizons, each with distinct characteristics and compositions.

5 Must Know Facts For Your Next Test

1. A typical soil profile consists of three main horizons: O (organic matter), A (topsoil), and B (subsoil).
2. The topmost layer, O horizon, is rich in organic material such as decomposed leaves and plants.
3. The A horizon, or topsoil, contains a mix of minerals, organic material, and is crucial for plant growth.
4. The B horizon, or subsoil, accumulates minerals leached from the A horizon and has a higher clay content.
5. Soil profiles vary significantly depending on factors like climate, vegetation, and parent material.

Review Questions

• What are the main horizons found in a typical soil profile?
• Why is the A horizon important for plant growth?
• How does climate affect the formation of a soil profile?

Related terms

Horizon: A distinct layer of soil within a soil profile.

Leaching: The process by which soluble substances are washed out from the soil.

Parent Material: The underlying geological material from which soil horizons develop.