LOCATION GRUNNEY                 CA

Tentative Series
PBR/RLR
07/2022

GRUNNEY SERIES


The Grunney series consists of very deep, poorly drained soils that formed in alluvium from mixed sources. Grunney soils are on floodplains and valley bottoms and have slopes of 0 to 9 percent. The mean annual precipitation is about 800 millimeters and the mean annual air temperature is about 8.5 degrees C.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Fluvaquentic Endoaquolls

TYPICAL PEDON: Grunney soils in an area of Grunney mucky loam on slope of 2 percent at 2280 meters elevation in a meadow. (Colors are for dry soil unless otherwise noted).

Oa--0 to 12 centimeters; very dark gray (10YR 3/1) muck, black (10YR 2/1), moist; moderate medium granular structure; neutral (pH 7.3); clear smooth boundary. (0 to 15 centimeters)

A1--12 to 32 centimeters; dark grayish brown (2.5Y 4/2) gravelly mucky loam, very dark grayish brown (2.5Y 3/2), moist; weak medium subangular blocky structure; very friable, slightly sticky, slightly plastic; common fine roots; common fine tubular pores; 10 percent medium prominent reddish brown (5YR 4/4), moist, and yellowish red (5YR 4/6), moist, iron-manganese masses; 20 percent gravel; neutral (pH 7.0); clear smooth boundary.

A2--32 to 39 centimeters; very dark gray (N 3/0) crushed, mucky silt loam; black (N 2.5/0), moist; weak medium granular structure; very friable, slightly sticky, slightly plastic; common fine roots throughout; common fine tubular pores; 10 percent medium prominent reddish brown (5YR 4/4), moist, and yellowish red (5YR 4/6), moist, iron-manganese masses; 10 percent gravel ; slightly acid (pH 6.2); clear wavy boundary. (A horizon thickness: 25-50 centimeters)

Cg--39 to 150 centimeters; 90 percent light gray (10YR 7/2) and 10 percent very dark gray (N 3/0) stratified loamy sand to sandy loam to silt loam, 60 percent gray (10YR 5/1), moist, and 30 percent light brownish gray (10YR 6/2), moist, and 10 percent black (N 2.5/0), moist; massive; very friable; nonsticky, nonplastic; 10 percent medium prominent irregular reddish brown (5YR 4/4), moist, and yellowish red (5YR 4/6), moist, iron-manganese concretions; slightly acid (pH 6.4).

TYPE LOCATION: San Bernardino County, California, 275 meters west and 120 meters south of the NE corner of section 36, T. 2 N., T. 1 W.; 34.22075 degrees latitude, -116.9295278 degrees longitude; NAD83; UTM Zone 11, 3786636n, 0506491e. U.S.G.S Quad Name: Big Bear Lake, California.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 10 to 15 degrees C.
Soil moisture: Usually dry in all parts from late May or early June until late November or early December, and saturated in the upper 50 centimeters the rest of the year.

Depth to water table: 0 to 50 centimeters
Organic matter: more than 4 percent
Rock fragments: 0 to 15 percent gravel
Reaction: moderately acidic to neutral

Oa horizon: (where present)
Dry color: N/2.5 or 10YR 2/2, 3/1
Moist color: N/2.5 or 10YR 2/1
Texture: muck or mucky peat

A horizons:
Dry color: 10YR 2/2, 3/1, 3/2
Moist color: 10YR 2/1, 2/2, 3/1 or N/2.5
Texture: loam, sandy loam, silt loam or has a mucky modifier
Clay content: 12 to 20 percent
Rock fragments: 0 to 25 percent gravel
Organic matter content: 6 to 18 percent

Cg horizon:
Dry color: 10YR 4/2, 5/2, 6/1, 6/2
Moist color: 10YR 3/3, 4/2, 4/3, 5/1, 5/2, 5/3, 6/1, 6/2
Texture: stratified sandy loam, loamy sand and silt loam
Rock fragments: 0 to 25 percent gravel

COMPETING SERIES:
Ambraw soils: 24 to 35 percent clay in the particle-size control section.
Gansner soils: have a cambic horizon.
Ozamis soils: 76 to 127 centimeters to a lithologic discontinuity and have a mean annual precipitation of 150 to 360 millimeters.
Settlemeyer soils: 25 to 35 percent clay in the particle-size section.
Sloan soils: averages 22 to 35 percent clay and is derived from alluvium from loamy, calcareous drift.
Toppenish soils: pH of 7.4 to 9.0 and has calcium carbonate in the surface layer.

GEOGRAPHIC SETTING:
Landscape: mountain valleys
Landform: floodplains and alluvial flats in valley bottoms
Parent Material: mixed alluvium predominantly from granitoid sources
Slope: 0 to 9 percent
Elevation: 1300 to 2350 meters
Climate: subhumid mesothermal with warm, dry summers and cool, moist winters with some snow.
Mean annual precipitation: 400 to 1050 millimeters
Mean annual temperature: 8 to 13 degrees C.
Frost-free season: 85 to 200 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Cariboucreek soils: have an argillic horizon and are on higher alluvial fans.
Doble soils: have very gravelly or very cobbly textures throughout and are on slightly higher alluvial fans.
Garloaf soils: have greater than 35 percent rock fragment, an argillic horizon and are on adjacent fan remnants.
Moonridge soils: have greater than 18 percent clay in the particle-size control section and are on slightly higher alluvial fans.
Shayroad soils: well drained and on slightly higher alluvial fans.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: poorly drained; moderate saturated hydraulic conductivity.

USE AND VEGETATION: Grunney soils are used for recreation, watershed and wildlife habitat. The present vegetation is mainly sedges, rushes, willows and scattered Jeffrey Pines.

DISTRIBUTION AND EXTENT: Inland mountain ranges of Southern California Coastal Plains and Mountains, MLRA 19. This soil is of small extent.

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

SERIES ESTABLISHED: San Bernardino Mountains, San Bernardino County, California 2004.

REMARKS:

Diagnostic horizons and features recognized in this pedon include:
Mollic epipedon: the zone from 12 to 39 centimeters
Aquic conditions: the zone from 12 to 150 centimeters
Particle-size control section: from a depth of 37 to 112 centimeters

ADDITIONAL DATA:

User Site ID: 2004CA071045
User Pedon ID: ca777-6874-69-E

Classified using the Twelfth Edition Keys to Soil Taxonomy (2014)


National Cooperative Soil Survey
U.S.A.