illuviación

Illuviation is a soil science term referring to the accumulation of leached materials in a lower soil horizon. These materials, often fine particles like clay, organic matter, or mineral compounds such as iron and aluminum oxides, are transported downward from the upper horizons by percolating water. This process is a key part of soil formation and influences the development of distinct soil horizons. The illuvial horizon, also known as the B horizon, is characterized by the deposition of these translocated substances. The type and amount of material illuviated can significantly affect the soil's physical and chemical properties, including its color, texture, structure, and fertility. Different soil orders are classified, in part, by the nature and extent of illuviation. For instance, in podzol soils, there is a distinct accumulation of organic matter and aluminum and iron compounds in the B horizon, known as the spodic horizon. In contrast, argillic horizons in other soils primarily feature an accumulation of clay. Understanding illuviation is crucial for comprehending soil profiles and their development over time.