A soil profile is a vertical cross-section of the soil that reveals its different layers, known as soil horizons, which run parallel to the surface
. These horizons are distinct in terms of their color, texture, structure, composition, and other physical or chemical properties
. The arrangement and sequence of these horizons from the surface down to the underlying rock is what constitutes the soil profile
. Main Layers (Horizons) of a Soil Profile:
- O Horizon: The topmost layer, rich in organic material such as decomposed leaves and plant matter. This layer is often dark in color and found mainly in forested areas
- A Horizon (Topsoil): Contains a mix of organic material with mineral particles. It is crucial for plant growth and is where most biological activity occurs
- E Horizon: Present in some soils, this layer is characterized by the leaching (removal) of minerals and nutrients from above, resulting in a lighter color
- B Horizon (Subsoil): Located below the A (and sometimes E) horizon, this layer accumulates minerals leached down from above, such as iron, clay, and aluminum
- C Horizon (Parent Material): Consists of weathered pieces of rock and little organic material. It is the source of the soil’s mineral content
- R Horizon (Bedrock): The lowest layer, made up of unweathered, solid rock
Each soil profile is unique and reflects the soil-forming processes and environmental conditions of its location. Examining a soil profile helps scientists, farmers, and engineers understand soil fertility, drainage, and suitability for various uses
