1. O Horizon (Organic Horizon):
- This is the uppermost horizon and consists of fresh or partially decomposed organic matter, such as leaves, twigs, and roots. It is commonly found in forest soils and is rich in organic matter and nutrients.
2. A Horizon (Topsoil):
- The A horizon lies beneath the O horizon and is the mineral soil layer that has undergone significant leaching, weathering, and biological activity. It is typically darker in color due to the presence of organic matter and has a crumbly structure.
3. E Horizon (Eluviation Horizon):
- The E horizon, also known as the zone of eluviation, is a light-colored layer that forms below the A horizon. It experiences the loss of clay particles, iron, and aluminum oxides through leaching, leaving behind a concentration of sand and silt.
4. B Horizon (Subsoil):
- The B horizon is the layer of subsoil beneath the E horizon. It is often denser and more compact than the A horizon. The B horizon accumulates clay minerals, iron oxides, and other materials that have been leached from the upper layers.
5. C Horizon (Parent Material):
- The C horizon represents the parent material from which the soil has developed. It is relatively undisturbed and contains weathered fragments of the original rock or sediment.
6. R Horizon (Bedrock):
- The R horizon is the underlying solid, unweathered bedrock or consolidated material that lies beneath the C horizon.
The sequence, thickness, and characteristics of soil horizons can vary depending on the specific soil-forming factors. The presence and development of particular horizons indicate different stages of soil formation and provide insights into the soil's history, properties, and suitability for various purposes, such as agriculture and engineering.
