Spodosols are acid soils characterized by a subsurface accumulation of humus that is complexed with Al and Fe. These photogenic soils typically form in coarse-textured parent material and have a light-colored E horizon overlying a reddish-brown spodic horizon. The process that forms these horizons is known as podzolization.

Spodosols often occur under coniferous forest in cool, moist climates. Globally, they occupy ~4% of the ice-free land area. In the US, they occupy ~3.5% of the land area.

Many Spodosols support forest. Because they are naturally infertile, Spodosols require additions of lime in order to be productive agriculturally.

Spodosols are divided into 5 suborders: Aquods, Gelods, Cryods, Humods, and Orthods. Click here for more information about these suborders. Click here to view a map of their distribution in the US.