Order:
[ ]
| Code |
Name |
Description |
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Vertisols that have, in one or more horizons within 50 cm of the mineral soil surface, aquic conditions for some time in normal years (or artificial drainage) and one or both of the following:
- In more than half of each pedon, either on faces of peds or in the matrix if peds are absent, 50 percent or more chroma of either:
- 2 or less if redox concentrations are present; or
- 1 or less; or
- Enough active ferrous iron (Fe2+) to give a positive reaction to alpha,alpha-dipyridyl at a time when the soil is not being irrigated.
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Other Vertisols that have a cryic soil temperature regime. |
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Other Vertisols that in normal years have both:
- A thermic, mesic, or frigid soil temperature regime; and
- If not irrigated during the year, cracks that remain both:
- 5 mm or more wide, through a thickness of 25 cm or more within 50 cm of the mineral soil surface, for 60 or more consecutive days during the 90 days following the summer solstice; and
- Closed for 60 or more consecutive days during the 90 days following the winter solstice.
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Other Vertisols that, if not irrigated during the year, have cracks in normal years that remain closed for less than 60 consecutive days during a period when the soil temperature at a depth of 50 cm from the soil surface is higher than 8 °C. |
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Other Vertisols that, if not irrigated during the year,
have cracks in normal years that are 5 mm or more wide, through a thickness of 25 cm or more within 50 cm of the mineral soil surface, for 90 or more cumulative days per
year. |
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Other Vertisols. |
Source:
Keys to Soil Taxonomy, Eighth Edition. 1998.
Links:
> > Suborders
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