Order:
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| Code |
Name |
Description |
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Ultisols that have aquic conditions for some time in normal years (or artificial drainage) in one or more horizons within 50 cm of the mineral soil surface and one or both of the following:
- Redoximorphic features in all layers between either the lower boundary of an Ap horizon or a depth of 25 cm from the mineral soil surface, whichever is deeper, and a depth of 40 cm and one of the following within the upper 12.5 cm of the argillic or kandic horizon:
- Redox concentrations and 50 percent or more redox depletions with chroma of 2 or less either on faces of peds or in the matrix; or
- 50 percent or more redox depletions with chroma of 1 or less either on faces of peds or in the matrix; or
- Distinct or prominent redox concentrations and 50 percent or more hue of 2.5Y or 5Y in the matrix and also a thermic, isothermic, or warmer soil temperature regime; or
- Within 50 cm of the mineral soil surface, enough active ferrous iron to give a positive reaction to alpha,alpha-dipyridyl at a time when the soil is not being irrigated.
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Other Ultisols that have one or both of the following:
- 0.9 percent (by weighted average) or more organic carbon in the upper 15 cm of the argillic or kandic horizon; or
- 12 kg/m2 or more organic carbon between the mineral soil surface and a depth of 100 cm.
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Other Ultisols that have a udic moisture regime. |
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Other Ultisols that have an ustic moisture regime. |
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Other Ultisols. |
Source:
Keys to Soil Taxonomy, Eighth Edition. 1998.
Links:
> > Suborders
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