(from Greek spodos, "wood ash") 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.