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JEG.Paleudalfs

Key to Great Groups 

JEG. Other Udalfs that:

1. Do not have a densic, lithic, or paralithic contact within 150 cm of the mineral soil surface; and

2. Within 150 cm of the mineral soil surface, either:

                a. Do not have a clay decrease with increasing depth of 20 percent or more (relative) from the maximum clay content [Clay is measured noncarbonate clay or based on the following formula: Clay % = 2.5(% water retained at 1500 kPa tension - % organic carbon), whichever value is greater, but no more than 100]; or

                b. Have 5 percent or more (by volume) skeletans on faces of peds in the layer that has a 20 percent lower clay content and, below that layer, a clay increase of 3 percent or more (absolute) in the fine-earth fraction; and

3. Have an argillic horizon with one or more of the following:

                a. In 50 percent or more of the matrix of one or more subhorizons in its lower one-half, hue of 7.5YR or redder and chroma of 5 or more; or

                b. 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, value, moist, of 3 or less, and value, dry, of 4 or less; or

                c. Many coarse redox concentrations with hue of 5YR or redder or chroma of 6 or more, or both, in one or more subhorizons; or

4. Have a frigid temperature regime and all of the following:

                a. An argillic horizon that has its upper boundary 60 cm or more below both:

                                (1) The mineral soil surface; and

                                (2) The lower boundary of any surface mantle containing 30 percent or more vitric volcanic ash, cinders, or other vitric pyroclastic materials; and

                b. A texture (in the fine-earth fraction) finer than loamy fine sand in one or more horizons above the argillic horizon; and

                c. Either a glossic horizon or interfingering of albic materials into the argillic horizon. Paleudalfs, p. 222 

JEG. Paleudalfs are the Alfisols that have a thick solum. These soils do not have a kandic or natric horizon, nor do they have a fragipan within 100 cm of the mineral soil surface. Some have an argillic horizon that shows evidence of destruction in the form of a glossic horizon, but they do not have both a glossic horizon and discrete iron-cemented nodules 2.5 to 30 cm in diameter. Paleudalfs are on relatively stable surfaces. Most of them are older than the Wisconsinan Glaciation. The time of soil formation dates from the Sangamon interglacial period or earlier. Base saturation commonly is lower than that in many other Alfisols. Before cultivation, most Paleudalfs in the United States had a vegetation of mixed deciduous hardwood forest. 

Definition 

Paleudalfs are the Udalfs that:

1. Do not have a kandic or natric horizon;

2. Do not have a fragipan with an upper boundary within 100 cm of the mineral soil surface;

3. Have a clay distribution in which the percentage of clay does not decrease from its maximum amount by as much as 20 percent within 150 cm of the soil surface, or the layer in which the clay percentage decreases by more than 20 percent has at least 5 percent of the volume consisting of skeletans on faces of peds and there is at least a 3 percent (absolute) increase in content of clay below this layer;

4. Do not have a densic, lithic, or paralithic contact within 150 cm of the soil surface;

5. Have an argillic horizon with one or more of the following:

                a. In 50 percent or more of the matrix of one or more subhorizons in its lower one-half, hue of 7.5YR or redder and chroma of 5 or more; or

                b. 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, value, moist, of 3 or less, and value, dry, of 4 or less; or

                c. Many coarse redox concentrations with hue of 5YR or redder or chroma of 6 or more, or both, in one or more subhorizons;

6. Do not have both a glossic horizon and, in the argillic horizon, discrete nodules, 2.5 to 30 cm in diameter, that are cemented or indurated with iron and that have exteriors with redder hue or higher chroma than the interiors; and

7. Have a frigid temperature regime and all of the following:

                a. An argillic horizon that has its upper boundary 60 cm or more below both:

                                (1) The mineral soil surface; and

                                (2) The lower boundary of any surface mantle containing 30 percent or more vitric volcanic ash, cinders, or other vitric pyroclastic materials; and

                b. A texture (in the fine-earth fraction) finer than loamy fine sand in one or more horizons above the argillic horizon; and

                c. Either a glossic horizon or interfingering of albic materials into the argillic horizon. 

Key to Subgroups 

JEGA. Paleudalfs that have one or both of the following:

1. Cracks within 125 cm of the mineral soil surface that are 5 mm or more wide through a thickness of 30 cm or more for some time in normal years, and slickensides or wedge-shaped aggregates in a layer 15 cm or more thick that has its upper boundary within 125 cm of the mineral soil surface; or

2. A linear extensibility of 6.0 cm or more between the mineral soil surface and either a depth of 100 cm or a densic, lithic, or paralithic contact, whichever is shallower. Vertic Paleudalfs 

JEGB. Other Paleudalfs that have, throughout one or more horizons with a total thickness of 18 cm or more within 75 cm of the mineral soil surface, a fine-earth fraction with both a bulk density of 1.0 g/cm3 or less, measured at 33 kPa water retention, and Al plus 1/2 Fe percentages (by ammonium oxalate) totaling more than 1.0. Andic Paleudalfs 

JEGC. Other Paleudalfs that have, throughout one or more horizons with a total thickness of 18 cm or more within 75 cm of the mineral soil surface, one or both of the following:

1. More than 35 percent (by volume) fragments coarser than 2.0 mm, of which more than 66 percent is cinders, pumice, and pumicelike fragments; or

2. A fine-earth fraction containing 30 percent or more particles 0.02 to 2.0 mm in diameter; and

                a. In the 0.02 to 2.0 mm fraction, 5 percent or more volcanic glass; and

                b. [(Al plus 1/2 Fe, percent extracted by ammonium oxalate) times 60] plus the volcanic glass (percent) is equal to 30 or more. Vitrandic Paleudalfs 

JEGD. Other Paleudalfs that have both:

1. Fragic soil properties:

                a. In 30 percent or more of the volume of a layer 15 cm or more thick that has its upper boundary within 100 cm of the mineral soil surface; or

                b. In 60 percent or more of the volume of a layer 15 cm or more thick; and

2. Redox depletions with chroma of 2 or less in layers that also have aquic conditions in normal years (or artificial drainage) either:

                a. Within the upper 25 cm of the argillic horizon if its upper boundary is within 50 cm of the mineral soil surface; or

                b. Within 75 cm of the mineral soil surface if the upper boundary of the argillic horizon is 50 cm or more below the mineral soil surface. Fragiaquic Paleudalfs 

JEGE. Other Paleudalfs that have both:

1. In one or more horizons within 75 cm of the mineral soil surface, redox depletions with chroma of 2 or less and also aquic conditions for some time in normal years (or artificial drainage); and 2. 5 percent or more (by volume) plinthite in one or more horizons within 150 cm of the mineral soil surface. Plinthaquic Paleudalfs 

JEGF. Other Paleudalfs that have both:

1. In one or more horizons within 75 cm of the mineral soil surface, redox depletions with chroma of 2 or less and also aquic conditions for some time in normal years (or artificial drainage); and

2. A glossic horizon or, in the upper part of the argillic horizon, one or more subhorizons that have 5 percent or more (by volume) clay depletions with chroma of 2 or less. Glossaquic Paleudalfs 

JEGG. Other Paleudalfs that have both:

1. In one or more horizons within 75 cm of the mineral soil surface, redox depletions with chroma of 2 or less and also aquic conditions for some time in normal years (or artificial drainage); and

2. A clay increase of 15 percent or more (absolute) in the fine-earth fraction within a vertical distance of 2.5 cm at the upper boundary of the argillic horizon. Albaquic Paleudalfs 

JEGH. Other Paleudalfs that have, in one or more horizons within 75 cm of the mineral soil surface, redox depletions with chroma of 2 or less and also aquic conditions for some time in normal years (or artificial drainage). Aquic Paleudalfs 

JEGI. Other Paleudalfs that have anthraquic conditions. Anthraquic Paleudalfs 

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

1. 20 or more consecutive days; or

2. 30 or more cumulative days. Oxyaquic Paleudalfs 

JEGK. Other Paleudalfs that have fragic soil properties:

1. In 30 percent or more of the volume of a layer 15 cm or more thick that has its upper boundary within 100 cm of the mineral soil surface; or

2. In 60 percent or more of the volume of a layer 15 cm or more thick. Fragic Paleudalfs 

JEGL. Other Paleudalfs that have both:

1. A sandy or sandy-skeletal particle-size class throughout a layer extending from the mineral soil surface to the top of an argillic horizon at a depth of 50 to 100 cm; and

2. 5 percent or more (by volume) plinthite in one or more horizons within 150 cm of the mineral soil surface. Arenic Plinthic Paleudalfs 

JEGM. Other Paleudalfs that have both:

1. A sandy or sandy-skeletal particle-size class throughout a layer extending from the mineral soil surface to the top of an argillic horizon at a depth of 100 cm or more; and

2. 5 percent or more (by volume) plinthite in one or more horizons within 150 cm of the mineral soil surface. Grossarenic Plinthic Paleudalfs 

JEGN. Other Paleudalfs that have an argillic horizon that:

1. Consists entirely of lamellae; or

2. Is a combination of two or more lamellae and one or more subhorizons with a thickness of 7.5 to 20 cm, each layer with an overlying eluvial horizon; or

3. Consists of one or more subhorizons that are more than 20 cm thick, each with an overlying eluvial horizon, and above these horizons there are either:

                a. Two or more lamellae with a combined thickness of 5 cm or more (that may or may not be part of the argillic horizon); or

                b. A combination of lamellae (that may or may not be part of the argillic horizon) and one or more parts of the argillic horizon 7.5 to 20 cm thick, each with an overlying eluvial horizon. Lamellic Paleudalfs 

JEGO. Other Paleudalfs that have a sandy particle-size class throughout the upper 75 cm of the argillic horizon or throughout the entire argillic horizon if it is less than 75 cm thick. Psammentic Paleudalfs 

JEGP. Other Paleudalfs that have a sandy or sandy-skeletal particle-size class throughout a layer extending from the mineral soil surface to the top of an argillic horizon at a depth of 50 to 100 cm. Arenic Paleudalfs 

JEGQ. Other Paleudalfs that have a sandy or sandy-skeletal particle-size class throughout a layer extending from the mineral soil surface to the top of an argillic horizon at a depth of 100 cm or more. Grossarenic Paleudalfs 

JEGR. Other Paleudalfs that have 5 percent or more (by volume) plinthite in one or more horizons within 150 cm of the mineral soil surface. Plinthic Paleudalfs 

JEGS. Other Paleudalfs that have either:

1. A glossic horizon; or

2. In the upper part of the argillic horizon, one or more subhorizons that have 5 percent or more (by volume) skeletans with chroma of 2 or less; or 3. 5 percent or more (by volume) albic materials in some subhorizon of the argillic horizon. Glossic Paleudalfs 

JEGT. Other Paleudalfs that have, in all subhorizons in the upper 100 cm of the argillic horizon or throughout the entire argillic horizon if less than 100 cm thick, more than 50 percent colors that have all of the following:

1. Hue of 2.5YR or redder; and

2. Value, moist, of 3 or less; and

3. Dry value no more than 1 unit higher than the moist value. Rhodic Paleudalfs 

JEGU. Other Paleudalfs that have a mollic epipedon, an Ap horizon that meets all of the requirements for a mollic epipedon except thickness, or materials between the soil surface and a depth of 18 cm that meet these requirements after mixing. Mollic Paleudalfs 

JEGV. Other Paleudalfs. Typic Paleudalfs 

Definition of Typic Paleudalfs 

Typic Paleudalfs are the Paleudalfs that:

1. Do not have, throughout a cumulative thickness of 18 cm or more and within a depth of 75 cm, one or more of the following:

                a. A bulk density, in the fraction less than 2.0 mm in size, of 1.0 g/cm3 or less, measured at 33 kPa water retention, and acid-oxalate-extractable aluminum plus 1/2 acid-oxalateextractable iron of more than 1.0 percent; or

                b. Fragments coarser than 2.0 mm constituting more than 35 percent of the whole soil and cinders, pumice, and pumicelike fragments making up more than 66 percent of these fragments; or

                c. A fine-earth fraction containing 30 percent or more particles 0.02 to 2.0 mm in diameter; and

                                (1) In the 0.02 to 2.0 mm fraction, 5 percent or more volcanic glass; and

                                (2) [(Al plus 1/2 Fe, percent extracted by ammonium oxalate) times 60] plus the volcanic glass (percent) is equal to 30 or more;

2. Do not have, in any horizon within 75 cm of the mineral soil surface, redox depletions with chroma of 2 or less and also aquic conditions and do not have an increase of 15 percent or more (absolute) clay within a vertical distance of 2.5 cm at the upper boundary of the argillic horizon;

3. Are not saturated with water in any layer within 100 cm of the mineral soil surface for 20 or more consecutive days or 30 or more cumulative days in normal years;

4. Do not have anthraquic conditions;

5. Have a texture finer than loamy fine sand in one or more subhorizons within 50 cm of the mineral soil surface;

6. Do not have, in all subhorizons in the upper 100 cm of the argillic horizon or throughout the entire argillic horizon if less than 100 cm thick, more than 50 percent colors that have all of the following:

                a. Hue of 2.5YR or redder; and

                b. Value, moist, of 3 or less; and

                c. Dry value no more than 1 unit higher than the moist value;

7. Have an argillic horizon that has a color value, dry, of 4.5 or more in some subhorizon, or a color value, moist, that is less than the value, dry, by more than 1 unit unless hue in some part of the argillic horizon is 5YR or yellower;

8. Do not have either:

                a. Cracks within 125 cm of the mineral soil surface that are 5 mm or more wide through a thickness of 30 cm or more for some time in normal years, and slickensides or wedge-shaped aggregates in a layer 15 cm or more thick that has its upper boundary within 125 cm of the mineral soil surface; or

                b. A linear extensibility of 6.0 cm or more between the mineral soil surface and either a depth of 100 cm or a densic, lithic, or paralithic contact, whichever is shallower;

9. Have less than 5 percent (by volume) plinthite in all subhorizons within 150 cm of the surface;

10. Have an argillic horizon that is finer than the sandy particle-size class in some part of the upper 75 cm if the argillic horizon is more than 75 cm thick or in any part if the argillic horizon is less than 75 cm thick;

11. Do not have a glossic horizon or subhorizons in the upper part of the argillic horizon that have clay depletions that:

                a. Have moist chroma of 2 or less; and

                b. Occupy 5 percent or more of the volume of the subhorizon;

12. Do not have albic materials that constitute as much as 5 percent of any subhorizon of the argillic horizon;

13. Have an argillic horizon that meets none of the following:

                a. Consists entirely of lamellae; or

                b. Is a combination of two or more lamellae and one or more subhorizons with a thickness of 7.5 to 20 cm, each layer with an overlying eluvial horizon; or

                c. Consists of one or more subhorizons that are more than 20 cm thick, each with an overlying eluvial horizon, and above these horizons there are either:

                                (1) Two or more lamellae with a combined thickness of 5 cm or more (that may or may not be part of the argillic horizon); or

                                (2) A combination of lamellae (that may or may not be part of the argillic horizon) and one or more parts of the argillic horizon 7.5 to 20 cm thick, each with an overlying eluvial horizon;

14. Have fragic soil properties:

                a. In less than 30 percent of the volume of all layers 15 cm or more thick that have an upper boundary within 100 cm of the mineral soil surface; and

                b. In less than 60 percent of the volume of all layers 15 cm or more thick;

15. Do not have a mollic epipedon, an Ap horizon that meets all of the requirements for a mollic epipedon except thickness, or materials between the soil surface and a depth of 18 cm that meet these requirements after mixing.

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