Order:
Suborder:
[ ]
| Code |
Name |
Description |
|
|
Udolls that have a natric horizon. |
|
|
Other Udolls that:
- Have a calcic or petrocalcic horizon that has its
upper boundary within 100 cm of the mineral soil surface; and
- Do not have an argillic horizon above the calcic or petrocalcic horizon; and
- In all parts above the calcic or petrocalcic horizon, after the materials between the soil surface and a depth of 18 cm have been mixed, either are calcareous or have a texture of loamy fine sand or coarser.
|
|
|
Other Udolls that have one or more of the following:
- A petrocalcic horizon that has its upper boundary within 150 cm of the mineral soil surface; or
- All of the following:
- No densic, lithic, or paralithic contact within 150 cm of the mineral soil surface; and
- Within 150 cm of the mineral soil surface, a clay decrease, with increasing depth, of less than 20 percent (relative) from the maximum clay content (noncarbonate clay); and
- An argillic horizon with one or more of the following:
- In 50 percent or more of the matrix of one or more subhorizons in its lower half, hue of 7.5YR or redder and chroma of 5 or more; or
- In 50 percent or more of the matrix of horizons that total more than one-half the total thickness, hue of 2.5YR or redder, a value, moist, of 3 or less, and a value, dry, of 4 or less; or
- Many redox concentrations with hue of 5YR or redder or chroma of 6 or more, or both, in one or more subhorizons; or
- A frigid temperature regime; and both
- An argillic horizon that has its upper boundary 60 cm or more below the mineral soil surface; and
- A texture finer than loamy fine sand in all horizons above the argillic horizon.
|
|
|
Other Udolls that have an argillic horizon. |
|
|
Other Udolls that have a mollic epipedon that:
- Either below an Ap horizon or below a depth of 18 cm from the mineral soil surface, contains 50 percent or more (by volume) wormholes, wormcasts, or filled animal burrows; and
- Either rests on a lithic contact or has a transition zone to the underlying horizon in which 25 percent or more of the soil volume consists of discrete wormholes, wormcasts, or animal burrows filled with material from the mollic epipedon and from the underlying horizon.
|
|
|
Other Udolls. |
Source:
Keys to Soil Taxonomy, Eighth Edition. 1998.
Links:
>
>
> Great Groups
|
