Horizon

Definition

A horizon is a distinct layer of soil that has unique physical and chemical properties compared to other layers. These horizons are part of the soil profile and influence plant nutrition and soil health.

5 Must Know Facts For Your Next Test

1. Horizons are identified by letters such as O, A, B, C, and R, each representing different characteristics.
2. The A horizon, also known as topsoil, is rich in organic material and crucial for plant growth.
3. B horizon or subsoil contains minerals leached from the A horizon but has less organic matter.
4. The C horizon consists of weathered parent material from which the upper layers derive.
5. Soil horizons form through processes like leaching, organic matter accumulation, and weathering.

Review Questions

Related terms

Soil Profile: A vertical section of soil that shows all its horizons.

Leaching: The process by which soluble substances are washed out of the soil into lower layers.

Organic Matter: Decayed plant and animal residues in the soil which contribute to fertility.