C-horizon

The C-horizon, also known as the regolith, is a soil horizon or layer beneath the B-horizon, characterized by partially weathered parent material. This zone comprises the substrate from which the soil develops, and often retains the original structure and composition of the bedrock or other geological materials. The C-horizon typically shows less biological activity than the overlying horizons, exhibiting weaker color development, fewer roots and a less complex structural arrangement. It represents the transition zone between the bedrock below and the developed soil profile above. The degree of weathering varies depending on climate, parent material, and time. Processes like physical and chemical weathering are still active, albeit at a slower rate, compared to the upper soil horizons. The C-horizon's characteristics influence water movement, nutrient availability, and root penetration within the soil profile.

C-horizon meaning with examples

• During soil analysis, the team identified a distinct C-horizon composed of fragmented shale, confirming the area's geological history. The slow rate of weathering suggested a stable environment. The relatively uniform composition and lack of developed structure differentiated it from the richer topsoil, indicating the underlying parent material’s influence on the soil development process.
• The agronomist assessed the C-horizon's properties, including its permeability and mineral composition, to understand water drainage patterns. The presence of specific minerals revealed insights into the underlying bedrock. This information helped evaluate potential impacts on crop yields, allowing optimized planting to increase yield, demonstrating how the properties of the C-horizon directly impact land use management decisions.
• Excavations revealed an undisturbed C-horizon layer, preserving ancient pollen and trace minerals in the soil. This discovery provided archaeologists with clues about past climates and vegetation. The analysis of the horizon, which contained artifacts, allowed the team to understand changes and the time periods they covered. The findings offered significant evidence to the prehistory of the area and its environment.
• The construction project required deep excavation, revealing the C-horizon directly beneath the topsoil and subsoil. This parent material contained large chunks of the original bedrock. The presence of this horizon influenced the planning of foundations and drainage systems, forcing the engineers to alter design. Its properties demonstrated the importance of understanding the soil's underlying structure for safe and effective construction.
• In arid regions, the C-horizon often exhibits a higher concentration of salts due to limited leaching and reduced rainfall. This process affects the water table and soil profile, creating soil and landscape challenges. Careful management, and understanding of the C-horizon is therefore, crucial for mitigating soil salinization. It allows the understanding of how the soil reacts to climate and environment, impacting the use of that area.