Spodosol BE
A representative soil profile of a Spodosol in Belgium. (Photo provided by Munsell Color.)
The central concept of Spodosols is the presence of a spodic horizon 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.
The spodic horizon may be destroyed by cultivation, yet spodic materials may still be present. In undisturbed soils there commonly is an overlying eluvial horizon, generally with a gray or light gray color similar to that of uncoated quartz. In some Spodosols this horizon is too thin to be preserved after cultivation, while in others it is very thick. Below the spodic horizon, there may be a fragipan or another sequum that has an argillic horizon. A few Spodosols have a placic horizon either on or within a spodic horizon or on a fragipan. Some Spodosols have layers thicker than a placic horizon that are cemented by spodic materials and organic matter (ortstein).
Spodosols are most extensive in areas of cool, humid or perhumid climates. They also formed, however, in hot, humid tropical regions and in warm, humid regions, where they occur mostly in areas of quartz-rich sands that have a fluctuating level of ground water. In many of the latter soils, the silt and sand fractions contain very few weatherable minerals and the albic horizons tend to be thick. Soils with an albic horizon 200 cm or more thick, however, are excluded from Spodosols and are grouped with Entisols. Some of the very deep spodic horizons may be buried, but it seems likely that others have formed at great depths because the overlying soil materials have very little iron and aluminum that could precipitate the organic carbon.
The Spodosols in the United States occur mainly in areas of late-Pleistocene or Holocene deposits. They are common in Alaska, in the higher mountains of the West, in the Great Lakes States, in the Northeast, and along the Atlantic coast of both the United States and Canada. They also occur in Northern Europe and northwestern Asia as well as New Zealand and southern Australia. Most are covered with coniferous or, less commonly, hardwood forests if they are not cultivated or grazed. In tropical areas the vegetation may be rain forest, palms, or a savanna that probably is anthropic. The moisture regime of Spodosols is mostly udic, but a few of the soils have a xeric regime. Some have aquic conditions. Spodosols may have any soil temperature regime. Spodosols are naturally infertile, but they can be highly responsive to good management. Under cultivation, the spodic horizon may be biologically destroyed, particularly if lime and nitrogen are applied.
For more information about determining accurate soil color, visit:
munsell.com/color-blog/soil-formation-process-archaeology/
For additional information about soil classification, visit:
www.nrcs.usda.gov/wps/portal/nrcs/main/soils/survey/class...
Spodosol BE
A representative soil profile of a Spodosol in Belgium. (Photo provided by Munsell Color.)
The central concept of Spodosols is the presence of a spodic horizon 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.
The spodic horizon may be destroyed by cultivation, yet spodic materials may still be present. In undisturbed soils there commonly is an overlying eluvial horizon, generally with a gray or light gray color similar to that of uncoated quartz. In some Spodosols this horizon is too thin to be preserved after cultivation, while in others it is very thick. Below the spodic horizon, there may be a fragipan or another sequum that has an argillic horizon. A few Spodosols have a placic horizon either on or within a spodic horizon or on a fragipan. Some Spodosols have layers thicker than a placic horizon that are cemented by spodic materials and organic matter (ortstein).
Spodosols are most extensive in areas of cool, humid or perhumid climates. They also formed, however, in hot, humid tropical regions and in warm, humid regions, where they occur mostly in areas of quartz-rich sands that have a fluctuating level of ground water. In many of the latter soils, the silt and sand fractions contain very few weatherable minerals and the albic horizons tend to be thick. Soils with an albic horizon 200 cm or more thick, however, are excluded from Spodosols and are grouped with Entisols. Some of the very deep spodic horizons may be buried, but it seems likely that others have formed at great depths because the overlying soil materials have very little iron and aluminum that could precipitate the organic carbon.
The Spodosols in the United States occur mainly in areas of late-Pleistocene or Holocene deposits. They are common in Alaska, in the higher mountains of the West, in the Great Lakes States, in the Northeast, and along the Atlantic coast of both the United States and Canada. They also occur in Northern Europe and northwestern Asia as well as New Zealand and southern Australia. Most are covered with coniferous or, less commonly, hardwood forests if they are not cultivated or grazed. In tropical areas the vegetation may be rain forest, palms, or a savanna that probably is anthropic. The moisture regime of Spodosols is mostly udic, but a few of the soils have a xeric regime. Some have aquic conditions. Spodosols may have any soil temperature regime. Spodosols are naturally infertile, but they can be highly responsive to good management. Under cultivation, the spodic horizon may be biologically destroyed, particularly if lime and nitrogen are applied.
For more information about determining accurate soil color, visit:
munsell.com/color-blog/soil-formation-process-archaeology/
For additional information about soil classification, visit:
www.nrcs.usda.gov/wps/portal/nrcs/main/soils/survey/class...