LOCATION POKEGEMA                OR

Established Series
Rev. JSC/AON/TDT/CEG/JTW
01/2020

POKEGEMA SERIES

Landscape--Lava plateaus
Landform--plateaus, hillslopes
Slope--1 to 40 percent
Parent material-- mudflow deposits containing andesitic rocks and ash
Mean annual precipitation--about 635 mm
Mean annual air temperature--about 6.7 degrees C
Depth class--very deep or deep to bedrock
Drainage class--well drained
Soil moisture regime--xeric
Soil temperature regime--frigid
Soil moisture subclass--typic

TAXONOMIC CLASS: Medial, amorphic, frigid Humic Haploxerands

TYPICAL PEDON: Pokegema medial loam, in coniferous forest, with a slope of 2 percent, at an elevation of 1342 m.

Oi--0 to 1 cm; slightly decomposed conifer needles.

A1--1 to 6 cm; medial loam, brown (7.5YR 4/2) dry, dark reddish brown (5YR 2/2) moist; weak very fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine roots; many very fine pores; 7 percent gravel, 3 percent cobbles; slightly acid (pH 6.5); abrupt smooth boundary

A2--6 to 21 cm; medial loam, reddish brown (5YR 4/3) dry, dark reddish brown (5YR 3/3) moist; weak very fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and coarse roots; many very fine tubular pores; 7 percent gravel, 3 percent cobbles; slightly acid (pH 6.5); gradual wavy boundary

BA--21 to 41 cm; medial loam, reddish brown (5YR 5/3) dry, dark reddish brown (5YR 3/3) moist; weak medium subangular blocky structure parting to moderate fine granular; slightly hard, friable, moderately sticky and slightly plastic; many fine and coarse roots; many very fine tubular pores; 7 percent gravel, 3 percent cobbles; slightly acid (pH 6.4); clear smooth boundary

Bw1--41 to 67 cm; gravelly medial loam, reddish brown (5YR 5/3) dry, dark reddish brown (5YR 3/3) moist; weak fine and medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; many fine and coarse roots; many very fine tubular pores; 15 percent gravel (mainly at a depth of 60 to 67 cm), 3 percent cobbles; slightly acid (pH 6.3); gradual smooth boundary

Bw2--67 to 97 cm; gravelly medial clay loam, brown (7.5YR 5/3) dry, dark reddish brown (5YR 3/3) moist; moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; many fine and coarse roots; many very fine tubular pores; 15 percent gravel and 5 percent cobbles; slightly acid (pH 6.1); clear wavy boundary

Bw3--97 to 133 cm; gravelly medial clay, reddish brown (5YR 4/3) dry, dark reddish brown (5YR 3/3) and reddish brown (5YR 4/4) moist; massive; hard, firm, moderately sticky and moderately plastic; few fine and coarse roots; common very fine tubular pores; 19 percent gravel, 5 percent cobbles; moderately acid (pH 5.8); abrupt wavy boundary

2R--133 cm; andesite.

TYPE LOCATION: Klamath County, Oregon; about 10 miles east of Pinehurst, approximately 35 feet south of the northeast corner of sec. 1, T. 40 S., R. 5 E., Willamette Meridian; Surveyor Mountain, Oregon, U.S. Geological Survey quadrangle; latitude 42.1266800 degrees, longitude -122.1719000 degrees, datum WGS 84 (coordinates estimated from PLSS details)

RANGE IN CHARACTERISTICS:
*Mean annual soil temperature--6.6 to 10 degrees C
*Moisture control section--dry for 45 to 60 consecutive days; xeric
*Depth to restriction--100 to over 200 cm to bedrock
*Mollic epipedon thickness--40 to 75 cm
*Andic soil properties--throughout the solum's thickness
Estimated Properties
*Volcanic glass content--15 to 30 percent
*Acid oxalate Al+1/2Fe--3 to 5 percent
*P-retention--75 to 100
*15-bar water--15 to 30 percent (dried samples)
*Acid oxalate extractable silica--2 to 3 percent

All mineral horizons
*Base saturation by sum of bases--50 to 75 percent
*Hue--7.5YR to 2.5YR.

The A and BA horizons
*Value--2 or 3 moist, 4 or 5 dry
*Chroma--2 through 4 moist or dry
*Rock fragments--less than 15 percent total rock fragments; 0 to 10 percent gravel; 0 to 6 percent cobbles
*Reaction--Slightly acid or neutral
*Organic matter content--5 to 10 percent in the A1 horizon; 1 to 5 percent in the A2 and BA horizons
*Thickness--22 to 50 cm, total combined A and BA horizons

Bw horizons
*Value--3 or 4 moist, 4 through 6 dry.
*Chroma--2 through 4 moist, 2 through 6 dry.
*Fine-earth texture--medial clay, medial clay loam or medial loam
*Clay content--20 to 45 percent; increases with depth
*Clay films--some pedons have clay films
*Rock fragments--5 to 20 percent gravel; 0 to 10 percent cobbles
*Reaction--moderately or slightly acid
*Thickness--43 to 150 cm

COMPETING SERIES:
Ahart--moderately deep to a paralithic contact
Greenwell--moderately deep to a paralithic contact

GEOGRAPHIC SETTING:
Elevation--1155 to 1980 m
Slope--1 to 40 percent
Climate--subhumid-continental with cold, moist winters and cool, dry summers
Mean annual precipitation--455 to 1145 mm
Mean annual air temperature--6.0 to 9.0 degrees C
Mean January air temperature-- -3.9 to -2.9 degrees C
Mean July air temperature--13.9 to 15 degrees C
Frost-free period--60 to 80 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Oatman--cryic
Woodcock--argillic horizon; medial-skeletal

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--Well drained
Saturated hydraulic conductivity (Ksat)--very high in O horizons; high in A and AB horizons; moderately high to high in Bw horizons

USE AND VEGETATION:
Use--timber production, wildlife habitat, livestock grazing, recreation
Overstory vegetation--Douglas-fir, ponderosa pine, white fir
Understory vegetation--common snowberry, western princes pine, western fescue and bush chinquapin

DISTRIBUTION AND EXTENT: Southern Oregon and northern California; MLRA 21; moderate extent.

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

SERIES ESTABLISHED: Jackson County Area, Oregon (Klamath County part), 1988.

REMARKS:
Diagnostic horizons and features recognized in this pedon
*Particle-size control section--zone from 1 to 133 cm
*Mollic epipedon--The zone from 1 to 67 cm
*Cambic horizon--The zone from 67 to 133 cm
*Andic soil properties--based on laboratory data from the associated Oatman and Tater soils
*Lithic contact--andesite bedrock at 133 cm

ADDITIONAL DATA:
*NASIS Site ID--S1966OR035001
*NASIS Pedon ID-- S1966OR035001
*Characterization data on 4 profiles (66 OR035-001, 002, 003, 004) reported in Riverside Soil Survey Laboratory report for Pokegema soils sampled in Klamath County, Oregon, 1966. Pedon 001 is the type location.

2010--Classification changed from Fine, halloysitic Pachic Cryoborolls to Medial, amorphic, frigid Alfic Humic Haploxerands.

07/2017--Updated this official series description according to SSRO1 Technical Note 11, OSD--Content and Format of Official Series Descriptions (revised 12/2015). Most of the changes were in formatting, with some changes to climate data as well.

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National Cooperative Soil Survey
U.S.A.