elluviivation

Elluviivation is a geological and soil-forming process that involves the downward movement of fine soil particles, such as clay and silt, through the soil profile under the influence of gravity and water. This process primarily occurs in humid climates where there is sufficient moisture to facilitate the leaching of materials from the upper layers of the soil. Unlike eluviation, which refers to the removal of materials from the upper soil horizon, elluviivation specifically describes the accumulation of these materials in lower layers, often resulting in distinct soil horizons.

The process begins with the breakdown of organic matter and minerals in the upper soil layers, particularly the A-horizon (topsoil). Rainwater percolates through the soil, dissolving and suspending fine particles, which are then transported downward by gravitational pull. Over time, this movement leads to the enrichment of lower horizons, such as the B-horizon (subsoil), with clay, iron oxides, and organic compounds. The accumulation of these materials can create a denser, more compact layer beneath the surface, influencing soil structure and fertility.

Elluviivation is closely related to other soil-forming processes, including podsolization and laterization, though it operates more broadly across different soil types and climates. It is particularly significant in temperate and tropical regions where weathering and leaching are active. The process can affect soil drainage, nutrient availability, and root penetration, making it an important factor in agricultural and ecological studies. Understanding elluviivation helps in assessing soil health, managing erosion, and optimizing land use practices.