LOCATION RACKERBY CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, active, thermic, shallow Typic Haploxerepts
TYPICAL PEDON: Rackerby very gravelly sandy loam, on an east facing 21 percent slope under a cover of blue oak, foothill pine, interior live oak, buckbrush, wild oat, rattlesnake brome, hedgehog dogtail, and Italian ryegrass at an elevation of 1770 feet, (540 m). When described on 9/14/1999 the soil was dry throughout. (Colors are for dry soil unless otherwise noted)
A--0 to 2 inches, (0 to 5 cm); dark yellowish brown (10YR 4/4) very gravelly sandy loam, dark brown (10YR 3/3) moist; 15 percent clay; moderate very fine and fine subangular blocky structure; slightly hard, very friable, nonsticky, nonplastic; many very fine roots; many very fine tubular pores; 40 percent subangular gravel; slightly acid, pH 6.4 by Hellige-Truog; abrupt smooth boundary. (1 to 2 inches, (3 to 5 cm) thick)
AB--2 to 5 inches, (5 to 13 cm); dark yellowish brown (10YR 4/4) gravelly sandy loam, dark yellowish brown (10YR 3/4) moist; 18 percent clay; moderate fine and medium subangular blocky structure; moderately hard, friable, slightly sticky, slightly plastic; many very fine roots; many very fine tubular pores; 30 percent subangular gravel; slightly acid, pH 6.4 by Hellige-Truog; clear wavy boundary. (3 to 6 inches, (8 to 15 cm) thick)
Bw--5 to 13 inches, (13 to 33 cm); yellowish brown (10YR 5/4) very gravelly sandy loam, dark yellowish brown (10YR 4/6) moist; 20 percent clay; strong medium subangular blocky structure; moderately hard, friable, slightly sticky, slightly plastic; common very fine roots; many very fine and fine tubular pores; 5 percent subangular cobbles and 35 percent subangular gravel; slightly acid, pH 6.3 by Hellige-Truog; clear smooth boundary. (6 to 9 inches, (15 to 23 cm) thick)
Cr--13 inches, (33 cm); weakly cemented quartz diorite bedrock.
TYPE LOCATION: Butte County, California; about 2.4 miles southwest of Hurleton, California, approximately 2000 feet south and 2600 feet west of the northeast corner of Section 34, Township 19 N., Range 5 E., 39 degrees, 27 minutes, 46.71 seconds North latitude; 121 degrees, 23 minutes, 57.82 seconds West longitude: NAD83-U.S.G.S. Quad: Bangor, California.
RANGE IN CHARACTERISTICS: Depth to paralithic bedrock is 10 to 20 inches, (25 to 51 cm). The mean annual soil temperature is 59 to 63 degrees F, (16 to 17 degrees C). The soil moisture control section is dry in all parts from about June through October (about 165 days). The particle-size control section averages 10 to 18 percent clay and 35 to 60 percent rock fragments, mostly gravel and cobbles. Mineralogy is mixed. Rock fragments on the surface range from 0 to 20 percent gravel, 0 to 5 percent cobbles and 0 to 5 percent stones. Some pedons have a BA horizon.
The A horizon dry color is 7.5YR 4/4, 4/6, 5/4 or 10YR 4/4. Moist color is 7.5YR 3/3, 3/4 or 10YR 3/3. Texture is gravelly loam, gravelly sandy loam, very gravelly sandy loam or gravelly coarse sandy loam. Clay content ranges from 8 to 16 percent. Rock fragments range from 15 to 40 percent gravel, 0 to 10 percent cobbles and 0 to 5 percent stones. Base saturation by sum of cations ranges from 60 to 70 percent. Organic matter ranges from 3 to 5 percent. Reaction is slightly acid.
The AB horizon dry color is 7.5YR 4/4, 4/6, 5/4, 5/6 or 10YR 4/4. Moist color is 7.5YR 3/3, 3/4, 4/4 or 10YR 3/4. Texture is gravelly loam, very gravelly loam, gravelly sandy loam, very gravelly sandy loam or gravelly coarse sandy loam. Clay content ranges from 10 to 20 percent. Rock fragments range from 25 to 45 percent gravel, 0 to 10 percent cobbles and 0 to 5 percent stones. Base saturation by sum of cations ranges from 60 to 70 percent. Organic matter ranges from 1.5 to 3 percent. Reaction is slightly acid.
The Bw horizon dry color is 7.5YR 4/6, 5/4, 5/6 or 10YR 5/4. Moist color is 7.5YR 3/4, 4/4, 4/6 or 10YR 4/6. Texture is very cobbly loam, very gravelly sandy loam, extremely cobbly sandy loam or very gravelly coarse sandy loam. Clay content ranges from 10 to 20 percent. Rock fragments range from 10 to 45 percent gravel, 5 to 70 percent cobbles and 0 to 5 percent stones. Base saturation by sum of cations ranges from 60 to 74 percent. Organic matter ranges from 0.2 to 1.0 percent. Reaction is slightly acid.
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: Rackerby soils are on side slopes on plutons in Sierra Nevada foothills. Slopes range from 15 to 30 percent. These soils formed in residuum and colluvium weathered from intrusive igneous rocks, mainly quartz diorite. Elevation is 500 to 2100 feet, (152 to 640 m). Mean annual precipitation is 32 to 45 inches, (813 to 1143 mm). The mean annual temperature is 57 to 60 degrees F, (14 to 16 degrees C). Frost free season is 235 to 260 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Flanly, Hurleton, Parkshill, and Swedesflat soils. Flanly soils are on ridge tops and foot slopes and are moderately deep to paralithic bedrock. Hurleton soils are moderately deep to lithic bedrock. Parkshill soils are very deep. Swedesflat soils are shallow to paralithic bedrock and are loamy.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately rapid saturated hydraulic conductivity in the A horizon and moderate to moderately rapid in the AB and Bw horizons.
USE AND VEGETATION: This soil is used for wildlife habitat, watershed, and homesite development. Vegetation is blue oak, foothill pine, scattered interior live oak, whiteleaf manzanita, toyon, buckbrush, Pacific poison oak, annual grasses and forbs.
DISTRIBUTION AND EXTENT: Butte County, California and occurs in (261Fb) Lower Foothills Metamorphic Belt subsection of the (M261F) Sierra Nevada Foothills section. MLRA 18 -Sierra Nevada Foothills. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Butte County, California 2005. Source of name from Rackerby, California.
REMARKS: These soils were previously mapped as Rough broken and stony land (Rb) and Sierra sandy loam (Si) in the Soil Survey of Oroville Area, California 1926.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - zone from 0 to 5 inches, (0 to 13 cm) (A and AB)
Cambic horizon - zone from 5 to 13 inches, (13 to 33 cm) (Bw)
Paralithic contact - 13 inches, (33 cm)
Particle-size control section - zone from 0 to 13 inches, (0 to 33 cm)
The soil moisture control section - zone from 0 to 13 inches, (0 to 33 cm).
Base saturation by sum of cations and Organic Matter are estimated from nearby lab data site