FFB.Hapluderts

Key to Great Groups 

FFB. Other Uderts. Hapluderts, p. 803 

FFB. Hapluderts are the Uderts with pH values that are dominantly above 5.0 in the upper 50 cm. These soils typically have high base saturation, and some have diagnostic horizons, including argillic horizons. Hapluderts occur on uplands and in lower areas. They formed in a variety of fine textured parent material, including alluvium. In the United States, these soils commonly occur in the Southeast but also occur on the northern Great Plains and in the Pacific Northwest. 

Definition 

Hapluderts are the Uderts that do not have both:

1. An electrical conductivity in the saturation extract of less than 4.0 dS/m at 25 oC; and

2. A pH value of 4.5 or less in 0.01 M CaCl2 (5.0 or less in saturated paste) in more than 50 percent of the soil volume between the mineral soil surface and a depth of 50 cm in each pedon. 

Key to Subgroups 

FFBA. Hapluderts that have a lithic contact within 50 cm of the mineral soil surface. Lithic Hapluderts 

FFBB. Other Hapluderts that have, in one or more horizons within 100 cm of the mineral soil surface, aquic conditions for some time in normal years (or artificial drainage) and either:

1. Redoximorphic features; or

2. Enough active ferrous iron (Fe2+) to give a positive reaction to alpha,alpha-dipyridyl at a time when the soil is not being irrigated. Aquic Hapluderts 

FFBC. Other Hapluderts that are saturated with water in one or more layers within 100 cm of the mineral soil surface in normal years for:

1. 20 or more consecutive days; or

2. 30 or more cumulative days. Oxyaquic Hapluderts 

FFBD. Other Hapluderts that have a densic, lithic, or paralithic contact within 100 cm of the mineral soil surface. Leptic Hapluderts 

FFBE. Other Hapluderts that have a layer 25 cm or more thick that contains less than 27 percent clay in its fine-earth fraction and has its upper boundary within 100 cm of the mineral soil surface. Entic Hapluderts 

FFBF. Other Hapluderts that have, in one or more horizons within 30 cm of the mineral soil surface, 50 percent or more colors as follows:

1. A color value, moist, of 4 or more; or

2. A color value, dry, of 6 or more; or

3. Chroma of 3 or more. Chromic Hapluderts 

FFBG. Other Hapluderts. Typic Hapluderts 

Definition of Typic Hapluderts 

Typic Hapluderts are the Hapluderts that:

1. Do not have a densic, lithic, or paralithic contact within 100 cm of the mineral soil surface;

2. Do not have, in any horizon within 100 cm of the mineral soil surface, aquic conditions and either:

                a. Redoximorphic features; or

                b. Enough active ferrous iron (Fe2+) to give a positive reaction to alpha,alpha-dipyridyl at a time when the soil is not being irrigated;

3. Do not have a layer 25 cm or more thick that contains less than 27 percent clay in its fine-earth fraction and has its upper boundary within 100 cm of the mineral soil surface;

4. Are not saturated with water in any layer within 100 cm of the mineral soil surface in normal years for:

                a. 20 or more consecutive days; or

                b. 30 or more cumulative days; and

5. Have, in all horizons within 30 cm of the mineral soil surface, 50 percent or more colors as follows:

                a. A color value, moist, of 3 or less; or

                b. A color value, dry, of 5 or less; or

                c. Chroma of 2 or less.

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