LOCATION PIGPEN                  CA

Established Series
Rev: JHP/JPS/ET
10/2016

PIGPEN SERIES

The Pigpen series consists of very deep, somewhat poorly drained soils formed in earthflow colluvium derived from mudstone and sandstone. Pigpen soils are on mountains and have slopes of 15 to 50 percent. The mean annual precipitation is about 2030 millimeters (80 inches) and the mean annual temperature is about 13 degrees C (55 degrees F).

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Aquultic Haploxeralfs

TYPICAL PEDON: Pigpen gravelly loam - on a hummocky, concave, southwest-facing slope of 32 percent under annual and perennial grasses, forbs, and rushes at 195 meters (640 feet) elevation. Colors are for dry soil unless otherwise stated. When described on April 29, 1986, the soil was moist to a depth of 120 cm with a water table present at 120 cm.)

A--0 to 15 centimeters (0 to 6 inches); grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and common fine roots; many very fine irregular, and many very fine and common fine tubular pores; 30 percent gravel; moderately acid (pH 6.0); clear wavy boundary. (10 to 30 centimeters thick)

AB--15 to 36 centimeters (6 to 14 inches); grayish brown (10YR 5/2) gravelly silty clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium and coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine and few fine tubular pores; 20 percent gravel and 5 percent cobbles; moderately acid (pH 6.0); clear wavy boundary. (10 to 25 centimeters thick)

Bt--36 to 81 centimeters (14 to 32 inches); variegated light yellowish brown (2.5Y 6/4) and gray (5Y 5/1) very cobbly silty clay loam, olive brown (2.5Y 4/4) and dark olive gray (5Y 3/2) moist; weak coarse and very coarse subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few very fine and fine roots; few very fine tubular pores; common faint clay films on faces of peds; common medium prominent yellowish brown (10YR 5/6) masses of iron accumulations, strong brown (7.5YR 5/8) moist; 20 percent gravel and 15 percent cobbles; strongly acid (pH 5.5); abrupt wavy boundary. (40 to 100 centimeters thick)

Cg--81 to 150 centimeters (32 to 59 inches); gray (N 5/) very gravelly clay loam, very dark gray (N 3/) moist; massive; hard, friable, slightly sticky and slightly plastic; few very fine roots; few very fine tubular pores; few medium distinct light yellowish brown (2.5Y 6/4) masses of iron accumulations, light olive brown (2.5Y 5/4) moist; 40 percent gravel and 10 percent cobbles; slightly alkaline (pH 7.5). (5 to 75 centimeters thick)

TYPE LOCATION: Redwood National Park, Humboldt County, California; in Raingage Earthflow Prairie; southeast quarter, southwest quarter, Section 35, T. 9 N., R. 2 E., WGS84 Decimal degrees 41.1230639 latitude and -123.9185528 longitude; HBLM; USGS Panther Creek Quadrangle. UTM Zone 10 422892mE 4552825mN; NAD83.

RANGE IN CHARACTERISTICS:

Soil Moisture: The soil is dry in all parts in the moisture control section from about July 10 to September 20, and is moist in all parts from about October 1 to June 1. The soils have a xeric moisture regime and an aquic subclass. A high seasonal water table ranges from 30 to 50 centimeters (12 to 20 inches) from November to April.

Soil Temperature: The mean annual soil temperature is 15 to 18 degrees C (59 to 64 degrees F). The difference between mean summer and mean winter temperature is 6 to 10 degrees C. The soil has a thermic soil temperature regime.

Base Saturation: (by sum of cations) is 30 to 41 percent in one or more subhorizons within the upper 75 centimeters of the argillic horizon.

The umbric epipedon is 25 to 50 centimeters thick. Depth to Redoximorphic features is 30 to 50 centimeters. Base saturation is greater than 30 percent, by ammonium acetate, and may be higher near the surface, reaches a minimum in the Bt and then increases with depth.

Surface fragments: 15 to 30 percent gravel.

Particle-Size Control Section (weighted average):
Rock fragments: 25 to 40 percent gravel and 10 to 20 percent cobbles.
Clay content: 27 to 35 percent clay.

A horizon
Hue: 10YR or 2.5Y.
Value: 4 or 6 dry, 2 through 4 moist.
Chroma: 2 or 3 dry, 1 through 3 moist.

Texture of fine earth: loam.
Rock fragments: 20 to 30 percent gravel and 0 to 5 percent cobbles.
Clay content: 20 to 26 percent clay.
Reaction is moderately to strongly acid.

Bt horizon
Hue: 10YR, 2.5Y, or 5Y.
Value: 4 through 7 dry, 3 through 6 moist.
Chroma: / through 4 dry, / through 4 moist.

Texture of fine earth: clay loam or silty clay loam.
Rock fragments: 20 to 40 percent gravel and 10 to 20 percent cobbles.
Clay content: 27 to 35 percent clay.
Reaction is moderately to strongly acid.

Redoximorphic features:
Hue: 7.5YR, 10YR, or 2.5Y.
Value: 5 or 6 dry, 4 through 6 moist.
Chroma: 4 or 6 dry, 4 through 8 moist.

Cg horizon
Hue: 5Y or N.
Value: 5 or 6 dry, 3 through 5 moist.
Chroma: / through 2 dry, / through 2 moist.

Texture of fine earth: clay loam or silty clay loam.
Rock fragments: 30 to 60 percent gravel and 0 to 35 percent cobbles.
Clay content: 30 to 35 percent clay.
Reaction is slightly acid to slightly alkaline.

Redoximorphic features:
Hue: 7.5YR, 10YR, or 2.5Y.
Value: 5 or 6 dry, 4 or 6 moist.
Chroma: 4 or 6 dry, 4 through 8 moist.

COMPETING SERIES: At this time there are no other series in this family.

GEOGRAPHIC SETTING: Pigpen soils are on earthflows on lower mountain slopes. Slopes are 15 to 50 percent. Elevations are 67 to 971 meters (215 to 3185 feet). The soils formed in earthflow colluvium derived from mudstone and sandstone. The climate is humid with cool, foggy summers and cool, rainy winters. Mean annual precipitation is 1780 to 2290 millimeters (70 to 90 inches). Mean January temperature is about 9 degrees C; mean July temperature is about 16 degree C; and the mean annual temperature is 10 to 15 degree C (50 to 59 degrees F). Frost free season is about 250 to 280 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Raingage soils. Raingage soils have less than 35 percent rock fragments in the particle-size control section and are on gentler, more uniform slopes with slower earthflow activity and around the peripheries of earthflow features.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat poorly drained; very high runoff; saturated hydraulic conductivity is moderately high in the surface layer, moderately low to low in the subsoil and very low in the substratum.

USE AND VEGETATION: This soil has been used for livestock grazing, recreation, wildlife habitat and watershed. The present vegetation is predominantly annual grasses and forbs, and some shrubs. Herbaceous species include dogtail grass, blando brome, slender wild oats, cranesbill, silver hairgrass, narrow-leaved flax and annual clover. Poison oak, blackberry and coyotebrush are common on sites disrupted by earthflow motion.

DISTRIBUTION AND EXTENT: California Coastal Redwood Belt; MLRA 4B. The series is not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.

SERIES ESTABLISHED: Humboldt and Del Norte area, California, 2007. The source of the name is from Pigpen Prairie, located next to Redwood National Park south of the town of Orick.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
1. Umbric epipedon - the zone from 0 to 36 centimeters (A & AB horizons)
2. Argillic horizon - the zone from 36 to 81 centimeters (Bt horizon)
3. Redoximorphic features - in the zone from 36 to 150 centimeters (Bt & Cg horizons)
4. Aquic conditions - seasonal water table, depleted matrix and aquic conditions for more than 30 days in most years within the zone from 36 to 150 centimeters (Bt & Cg horizons)
5. Particle-size control section - the zone from 36 to 81 centimeters, averages 33 percent clay, by field estimate, and 35 percent rock fragments, by volume. CEC/clay ratio averages 0.65

ADDITIONAL DATA: NASIS User Pedon ID: 86CA605REDW011

Soil sample 89-RNP-10 and 89-RNP-8 were collected from similar pedons and analyzed chemically at the Oregon state University Soil Testing Laboratory.

Soil classified using the 12th Edition of the Keys to Soil Taxonomy.

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National Cooperative Soil Survey
U.S.A.