LOCATION GROMMET                 CA

Established Series
RLR/KP/RLR
03/2017

GROMMET SERIES

The Grommet series are well drained soils that formed in alluvium from mixed sedimentary sources. Grommet soils are on alluvial fans and inset fans. Slopes range from 0 to 12 percent. The mean annual precipitation is about 410 millimeters and the mean annual temperature is about 18 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Pachic Haploxerolls

TYPICAL PEDON: Grommet, on a 4 percent slope under in a maintained lawn at an elevation of 87 meters. When described the soil was dry throughout. (Colors are for dry soil unless otherwise noted).

^A1--0 to 15 centimeters; brown (10YR 5/3) loam, very dark grayish brown (10YR 3/2), moist; weak fine granular structure; friable, slightly hard, moderately sticky, slightly plastic; common fine and very fine roots; common fine interstitial pores; 2 percent gravel; neutral (pH 7.3); clear wavy boundary.

A2--15 to 45 centimeters; loam, dark brown (10YR 3/3), moist; massive; friable, moderately sticky, slightly plastic; common very fine roots; few fine and common very fine tubular pores; 2 percent gravel; neutral (pH 7.3); moderately compacted; clear wavy boundary.

C1--45 to 95 centimeters; loam, dark brown (10YR 3/3), moist; massive; friable, moderately sticky, slightly plastic; few very fine roots; common fine tubular and many very fine interstitial pores; 2 percent slate gravel; neutral (pH 7.3); gradual wavy boundary.

C2--95 to 190 centimeters; loam, dark yellowish brown (10YR 3/4), moist; massive; friable, moderately sticky, slightly plastic; 2 percent slate gravel; neutral (pH 7.3).

TYPE LOCATION: Los Angeles County, California, Westwood Recreation Center, Los Angeles City Parks. Near Ventura Avenue in southern block of park between several anthropogenic mounds. 34 degrees, 3 minutes, 13 seconds North latitude and 118 degrees, 26 minutes, 41 seconds West longitude, WGS84 - U.S.G.S Quad: Beverly Hills.

RANGE IN CHARACTERISTICS:

Soil moisture: The soil becomes moist below a depth of about 30 centimeters some time from October to December and remains moist in some part between depths of about 30 to 90 centimeters until April or May.
Mean annual soil temperature: 16 to 19 degrees C (60 to 66 degrees F). The soil temperature usually does not go below 8 degrees C (47 degrees F).

Rock fragments: 0 to 5 percent throughout; individual horizons may have up to 15 percent fragments near canyons.
Reaction: neutral to slightly alkaline.
Clay Content: 18 to 28 percent, some pedons have up to 33 percent clay
Human-transported materials: variable surface thickness and less than 50 cm thick (20 inches).

A, ^A(u) horizon:
Dry Color - hue of 10YR or 7.5YR, value of 4 or 5, chroma of 2 or 3
Moist Color - hue of 10YR, value of 2 or 3, chroma of 2 or 3
Texture - loam, fine sandy loam, silt loam. Some pedons are clay loam
Rock fragment: 0 to 5 percent
Artifacts may or may not be present. Usually less than 10 percent variable construction debris.

C, C(u) horizon:
Color - hue of 10YR or 7.5YR, value of 3 to 5, chroma of 3 to 4
Texture - loam, fine sandy loam, silt loam. Some pedons are clay loam
Rock fragment: 0 to 5 percent
Artifacts may or may not be present.

COMPETING SERIES:
These are the Agueda, Alendra, Anaheim, Carranza, Conejo, Gazos, Reward, Salinas, Stevenscreek and Westfan soils.
Agueda soil: are formed in material weathered from calcareous sedimentary rocks.
Almendra soils: have a mean annual precipitation of 508 to 660 mm and frost free season of 245 to 255 days.
Anaheim soils: have a paralithic contact at a depth of 50 to 100 centimeters.
Carranza soils: have 25 to 35 percent clay in the particle size control section.
Conejo soils: have a slightly cooler mean annual soil temperature and higher mean annual precipitation.
Gazos soils: have a lithic contact at a depth of 50 to 100 centimeters.
Reward soils: have a lithic contact at a depth of 100 to 150 centimeters.
Salinas soils: have calcium carbonate in the subsoil.
Stevenscreek soil: have a slightly cooler mean annual soil temperature and have 27 to 35 percent clay in the control section.
Westfan soils: are calcareous below a depth of 50 to 100 centimeters and has a frost free season of 225 to 250 days.

GEOGRAPHIC SETTING:
Landscape: coastal plains.
Landform: alluvial fans, inset fans, and stream terraces.
Slopes: 0 to 12 percent.
Parent material: alluvium weathered from slate or other sedimentary sources.
Elevation: 0 to 450 meters.
Mean annual precipitation: 300 to 525 mm.
Mean annual temperature: 16 to 19.5 degrees C.
Frost free season: 320 to 365 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Centinela, Hueneme, Palmview, Pierview, and San Emigdio soils.
Centinela soils: have greater than 35 percent clay and occur on similar landscape positions.
Hueneme soils: have less than 18 percent clay, are somewhat poorly drained and occur on alluvial fans.
Palmview soils: have less than 18 percent clay, and occur on alluvial fans derived from granitic sources.
Pierview soils: have an argillic horizon that extends below a depth of 150 cm and occur on alluvial fan remnants.
San Emigdio soils: have less than 18 percent clay and occur on alluvial fans.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; moderate saturated hydraulic conductivity. Flooding is none or very rare.

USE AND VEGETATION: This soil is used for cultivation of fruit/vegetable crops and urban residential or commercial development.

DISTRIBUTION AND EXTENT: Coastal plains and valleys in MLRA 19 - Southern California Coastal Plain. These soils are moderately extensive.

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

SERIES ESTABLISHED: Los Angeles County, Southeastern Part, California, 2015.

REMARKS: Surface disturbance (designated with the ^) is not series criteria and may or may not be present (non-restrictive if present).

Diagnostic horizons and features recognized in this pedon are:
Mollic Epipedon: the zone from a depth of 0 to 95 cm
Particle Size Control Section: the zone from a depth of 25 to 100 cm

Gravel in the surface horizon of the Type location is mixed aggregate from road construction.

ADDITIONAL DATA:

NASIS USER SITE ID: S2014CA037006
NASIS USER PEDON ID: S2014CA037006
Classified using the Twelfth Edition Keys to Soil Taxonomy (2014)

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National Cooperative Soil Survey
U.S.A.