A soil profile is a cross section through the soil which reveals its horizons (layers). Soil generally consists of visually and texturally distinct layers, which can be summarised as follows, from top to bottom:
- A) Humus: organic matter in relatively undecomposed form. This layer tends to be dark and rich in smell and texture.
- B) Topsoil: well decomposed organic matter, mixed with a smaller amount of minerals.
- C) Layer of mixed decomposed organic matter and mineral content.
- D) Subsoil or mineral layers, the content of which varies according to the nature of the soil and its parent material.
- E) Bedrock or parent material, which breaks down at the upper surface due to the effects of weathering and decay.[]