LOCATION WUTCHUMNA CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Mollic Haploxeralfs
TYPICAL PEDON: Wutchumna gravelly clay loam, on a hillside at an elevation of 580 feet. (Colors are for dry soil unless otherwise noted).
A1--0 to 1 inches; brown (7.5YR 4/4) gravelly clay loam, dark brown (7.5YR 3/4) moist; moderate thin platy parting to moderate fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine vesicular pores; 15 percent gravel; neutral (pH 6.8); abrupt wavy boundary. (1 to 3 inches thick).
A2--1 to 4 inches; brown (7.5YR 4/4) gravelly clay loam, dark brown (7.5YR 3/4) moist; weak very coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine, few fine and medium tubular pores; 15 percent gravel; neutral (pH 6.8); abrupt wavy boundary. (3 to 5 inches thick).
Bt1--4 to 12 inches; brown (7.5YR 4/4) gravelly clay loam, dark brown (7.5YR 3/4) moist; weak very coarse prismatic breaking to moderate medium subangular blocky structure; slightly hard, very friable, sticky and slightly plastic; common very fine roots; many very fine, few fine and medium tubular pores; few very fine prominent black (N 2/0) manganese stains on ped faces; few thin clay films on ped faces; 15 percent gravel; neutral (pH 7.2); clear wavy boundary. (4 to 10 inches thick).
Bt2--12 to 18 inches; brown (7.5YR 4/4) gravelly clay loam, dark brown (7.5YR 3/4) moist; weak very coarse prismatic parting to moderate medium subangular blocky structure; slightly hard, very friable, sticky and slightly plastic; common very fine roots; many very fine, few fine and medium tubular pores; common very fine prominent black (N 2/0) manganese stains on ped faces; common thin clay films on ped faces and few thin clay films lining pores; 15 percent gravel; neutral (pH 7.2); clear wavy boundary. (4 to 8 inches thick).
Bt3--18 to 27 inches; reddish brown (5YR 4/4) gravelly clay, dark reddish brown (5YR 3/4) moist; weak medium subangular blocky structure; hard, friable, very sticky and very plastic; common very fine roots; common very fine and fine tubular pores; common very fine prominent black (N 2/0) manganese stains on ped faces and gravels; common thin clay films on ped faces and lining pores; 20 percent gravel and 10 percent cobbles; slightly alkaline (pH 7.4); abrupt wavy boundary. (4 to 12 inches thick).
Bt4--27 to 35 inches; yellowish red (5YR 5/6) gravelly clay, yellowish red (5YR 4/6) moist; moderate medium subangular blocky structure; hard, firm, very sticky and very plastic; few very fine roots; common very fine and fine tubular pores; common very fine prominent black (N 2/0) manganese stains on ped faces and gravels; many very thin and moderately thick clay films on ped faces and lining pores; 20 percent gravel and 10 percent cobbles; slightly alkaline (pH 7.4); abrupt wavy boundary. (4 to 16 inches thick).
2R--35 inches; meta-gabbro.
TYPE LOCATION: Tulare County, California; about 2 miles east of the community of Ivanhoe; approximately 900 feet north and 1700 feet west of the southeast corner of section 5, T. 18 S., R. 26 E., MBD&M; Latitude 36 degrees, 23 minutes, 13 seconds north and Longitude 119 degrees, 10 minutes, 30 seconds west; Ivanhoe Quadrangle.
RANGE IN CHARACTERISTICS:
Mean Annual Soil Temperature: 64 to 67 degrees F.
Depth to argillic horizon - 4 to 8 inches. When this depth is greater than 6 inches, the depth to the base of the argillic is always greater than 30 inches. Depth to bedrock - 20 to 40 inches.
Particle Size Control Section - Clay content: ranges from 32 to 60 percent but always averages greater than 35 percent. Texture: Gravelly clay loam or gravelly clay. Rock fragments: 15 to 35 percent of which 15 to 35 percent are gravel and 0 to 10 percent are cobbles.
Profile Reaction: Neutral to slightly alkaline.
Bt and 2Bt horizons - Hue: 7.5YR or 5YR.
Other features: These horizons contain few to common manganese stains on ped faces and gravel.
COMPETING SERIES: These are the Argonaut (CA), Conosta (CA), Contra Costa (CA), Fancher (T CA), Kilaga (CA), Phipps (CA), Trabuco (CA) and Yeguas (T CA) soils. Argonaut, Conosta and Fancher soils are 20 to 40 inches to a paralithic contact. Contra Costa soils have Bt horizons with 35 to 45 percent clay, BC horizons, and are 20 to 40 inches to sandstone and shale. Kilaga soils are 40 to 80 inches to duripan or stratified alluvium. Phipps soils are very deep and are 20 to 45 inches to a C horizon. Trabuco soils are 40 to 80 inches to paralithic contact and are well drained. Yeguas soils are 40 to 60 inches deep and have Bk horizons.
GEOGRAPHIC SETTING: Wutchumna soils are on side slopes of hills. These soils formed in residuum and colluvium weathered from meta-gabbro. Slopes are 5 to 50 percent. Elevations are 340 to 870 feet. The climate is characterized by hot dry summers and cool moist winters. The mean annual precipitation is 9 to 11 inches. The mean annual temperature is 62 to 65 degrees F. and the frost free season is 250 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Centerville, Exeter, Grangeville and San Joaquin soils. All these soils lack a lithic contact within the profile.
DRAINAGE AND PERMEABILITY: Well drained; high or very high runoff; slow permeability.
USE AND VEGETATION: Cattle production and wildlife habitat. Vegetation is annual grasses and forbs.
DISTRIBUTION AND EXTENT: Wutchumna soils are of small extent in the central San Joaquin valley. MLRA is 17.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Tulare County, Western Part Soil Survey, California, 1994. The series name is from a local drainage.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric Epipedon -- The zone from the soil surface to about 4 inches (A1 and A2 horizons).
Argillic Horizon -- The zone from 4 inches to about 35 inches (Bt1, Bt2, Bt3 and 2Bt4 horizons).