soilhorizon

A soil horizon is a layer of soil that has distinct characteristics, such as color, texture, structure, and composition, which differ from the layers above and below it. Soil horizons are typically identified by their depth and the processes that have shaped them. The most common soil horizons are:

1. O horizon: This is the topmost layer, composed of organic material such as leaf litter, peat, and humus. It is often found in forest soils and is rich in nutrients.

2. A horizon: Also known as the topsoil, this layer is typically dark in color due to the presence of organic matter. It is well-aerated and contains a mix of minerals and organic material.

3. E horizon: This layer is often found in grasslands and is characterized by the leaching of clay and other minerals, leaving behind a lighter-colored layer.

4. B horizon: This layer, also known as the subsoil, is typically lighter in color than the A horizon due to the leaching of minerals. It may contain clay, iron, or other minerals that have been transported from above.

5. C horizon: This layer is composed of weathered parent material, such as rock or sediment, and is often found below the B horizon.

6. R horizon: This is the bedrock layer, which is the parent material from which the soil has formed.

Soil horizons are important for understanding soil formation, nutrient cycling, and plant growth. They are typically identified and described using a soil profile, which is a vertical cross-section of the soil. The characteristics of soil horizons can vary greatly depending on factors such as climate, parent material, and vegetation.