podzolization

Podzolization is a soil-forming process, particularly in humid regions, that involves leaching from upper soil layers and the accumulation of material in lower layers, creating distinct soil horizons. This process specifically leads to the development of a podzol soil.12

Podzols typically form under forested landscapes on coarse, quartz-rich parent material. They are characterized by a spodic horizon composed of accumulated humus and metal oxides, usually iron and aluminum. Above this, a bleached layer often exists where clay and iron oxides have been leached out, leaving behind coarse-textured material with primary minerals and little organic matter. These soils are often acidic and difficult to cultivate. Podzolic soils, a related type, are found in broadleaf forests and are marked by moderate leaching that causes clay and iron accumulation. The key difference is that in podzolic soils, humic acid primarily causes clay eluviation, while in podzols, it's iron eluviation or the leaching of all weathering products.23