The central concept of Spodosols is that of soils in which amorphous mixtures of organic matter and aluminum, with or without iron, have accumulated. In undisturbed soils there is normally an overlying eluvial horizon, generally gray to light gray in color, that has the color of more or less uncoated quartz.

Most Spodosols have little silicate clay. The particle-size class is mostly sandy, sandy-skeletal, coarse-loamy, loamy, loamy- skeletal, or coarse-silty.

Dominant Suborders

Aquods

Aquods are the wet Spodosols. They are characterized by a shallow fluctuating water table. They are in Florida and along the Atlantic coast. The vegetation is water-loving plants, ranging from moss, shrubs, and trees in cold areas to mixed forests and palms in the warmest areas. Most Aquods are used as forest or wildlife habitat. Some, mostly in Florida and New Jersey, have been cleared and are used as cropland or pasture. Aquods are naturally infertile, but they can be highly responsive to good management.

Cryods

Cryods are the cold Spodosols of high latitudes and/or high elevations. They are mostly in southern Alaska and in the mountains of Washington and Oregon. Some are in the high mountains of New York and northern New England. The vegetation is mostly coniferous forest. Most Cryods are used as forest or wildlife habitat.

Humods

Humods are the relatively freely drained Spodosols that have a large accumulation of organic carbon in the spodic horizon. They are mostly in Washington State, but a few are known to occur on tropical islands and in the Northeastern and Southeastern States. Most Humods formed under coniferous forest vegetation. These soils are used mainly as forest.

Orthods

Orthods are the relatively freely drained Spodosols that have a moderate accumulation of organic carbon in the spodic horizon. They are most extensive in the Northeastern United States and the Great Lakes States. Most Orthods are used as forest or have been cleared and are used as cropland or pasture. Orthods are naturally infertile, but they can be highly responsive to good management. The spodic horizon can be destroyed under cultivation, particularly if lime and nitrogen are applied.

Spodosols a spodic horizon or spodic materials, both of which consist of accumulated amorphous mixtures of organic matter and aluminum, with or without iron. Spodosols are most extensive in areas of cool, humid or perhumid climates in the Northeastern States, southern Alaska, the Great Lakes States, and the high mountains of the Northwestern States. Spodosols are naturally infertile soils, but they can be highly responsive to good management.