LOCATION PITTVILLE CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Argixerolls
TYPICAL PEDON: Pittville sandy loam on a north facing 1 percent slope under a cover of rabbitbrush, squirreltail, antelope bitterbrush, and scattered western juniper at an elevation of 3325 feet. (Colors are for dry soil unless otherwise stated. When described June 3, 1981, the soil was slightly moist throughout.)
A1--0 to 5 inches; brown (10YR 5/3) sandy loam, very dark grayish brown (10YR 3/2) moist; moderate medium platy structure; slightly hard, very friable, slightly sticky and nonplastic; common very fine roots; common very fine and few fine tubular pores; neutral (pH 7.0); abrupt wavy boundary.
A2--5 to 9 inches; brown (10YR 5/3) sandy loam, very dark grayish brown (10YR 3/2) moist; weak thick platy structure; hard, friable, slightly sticky and nonplastic; common very fine roots; common very fine and few fine tubular pores; neutral (pH 7.0); abrupt smooth boundary. (Combined thickness of the A horizon is 9 to 16 inches)
Bt1--9 to 16 inches; grayish brown (10YR 5/2) sandy clay loam, very dark grayish brown (10YR 3/2) moist; weak coarse subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine and few fine and medium roots; common very fine and few fine tubular pores; few thin clay films on peds and many thin clay films as bridges between mineral grains; neutral (pH 7.0); clear smooth boundary. (5 to 8 inches thick)
Bt2--16 to 24 inches; brown (10YR 5/3) sandy clay loam, dark brown (10YR 4/3) moist; weak coarse subangular blocky structure; hard, friable, sticky and slightly plastic; common very fine and few fine roots; common very fine and few fine tubular pores; common thin clay films on peds, and many thin clay films in pores; neutral (pH 7.0); clear wavy boundary.
Bt3--24 to 31 inches; brown (10YR 5/3) sandy clay loam, dark brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard, friable, sticky and plastic; common very fine and few fine roots; common very fine and few fine tubular pores; many thin clay films on peds and in pores; neutral (pH 7.0); clear wavy boundary. (Combined thickness of the Bt1, Bt2, and Bt3 horizons is 20 to 40 inches)
Bt4--31 to 41 inches; light yellowish brown (10YR 6/4) sandy clay loam, dark brown (10YR 4/3) moist; weak coarse subangular blocky structure, slightly hard, very friable, nonsticky and nonplastic; common very fine and few fine roots; common very fine and few fine tubular pores; common thin clay films on peds and many thin clay films in bridges between mineral grains; neutral (pH 7.0); gradual wavy boundary. (8 to 12 inches thick)
2Bt5--41 to 49 inches; light yellowish brown (10YR 6/4) loamy sand, dark brown (10YR 3/3) moist; weak coarse subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common very fine and few fine roots; common very fine interstitial pores; common thin clay films as bridges between mineral grins; neutral (pH 7.0); gradual wavy boundary. (8 to 10 inches thick)
3Bq--49 to 84 inches; light brownish gray (10YR 6/2) sand, very dark grayish brown (10YR 3/2) moist; massive; soft, friable, nonsticky and nonplastic; few very fine roots; common very fine interstitial pores; slight silica cementation; neutral (pH 7.0); abrupt smooth boundary. (35 to 40 inches thick)
3Bqm--84 inches; lacustrine tuff in laminar layers.
TYPE LOCATION: Shasta County, California; about 2.0 miles west on Dean Knoch Road from the intersection of Pittville Road and Dean Knoch Road, 1600 feet south of Dean Knoch Road in field; 300 feet east and 2300 feet north of the southwest corner of section 23, T.37 N., R.5 E., Fall River Mills SE (Pittville) Quandrangle (7.5 minute series).
RANGE IN CHARACTERISTICS: Thickness of the A and Bt horizons is greater than 60 inches. Depth to Lacustrine tuff is greater than 60 inches. The mean annual soil temperature is 52 to 54 degrees F. The soil temperature exceeds 41 degrees F. from early March to late December (305 days) and exceeds 47 degrees F. from mid May to late November. The soil moisture control section (7 to 20 inches) is dry in all parts from early July to mid November (130 to 140 days) and is moist in all parts from early December to mid May. The particle control section (9 to 29 inches) ranges from 20 to 30 percent clay and 0 to 5 percent rock fragments, mostly gravel.
The A horizon color is 10YR 4/2, 5/2, or 5/3. Moist color is 10YR 3/2; or 7.5YR 3/2. Organic matter ranges from 2 to 4 percent. Clay content ranges from 10 to 18 percent. Rock fragments, mostly gravel range from 0 to 10 percent. Reaction ranges from slightly acid or neutral.
The upper Bt horizon color is 10YR 4/2, 5/2, 5/3, or 5/4. Moist color is 10YR 3/2, 4/2, 4/3; 7.5YR 3/2,or 4/4. Organic matter ranges from 1 to 0.5 percent. Clay content ranges from 20 to 30 percent. Rock fragments, mostly gravel, range from 0 to 15 percent. Reaction ranges from slightly acid or neutral.
The lower Bt and Bq horizons color is 10YR 5/2, 5/3, 6/2, 6/4, 7/3, or 8/3. Moist color is 10YR 3/3, 3/2, 4/2, 4/3, 4/4, or 5/3. Organic matter is less than 0.2 percent. Texture is sand, loamy sand, or sandy loam. Clay content ranges from 5 to 15 percent. Rock fragments, mostly gravel, range from 5 to 15 percent.
COMPETING SERIES: These are the Ahsahka (T ID), Buckbay (T CA), Colma (CA), Drangnot (CA), Duzel (CA), Facey (CA), Farrot (ID), Foehlin (OR), Hatspring (T WA), Immiant (ID), Jauriga (T CA), Ladd (OR), Lobitos (CA), Los Gatos (CA), Mehlhorn (ID), Taneum (WA), Tieton (WA), Tweedy (CA) and Voilmer (T ID) series. Buckbay, Duzel, Farrot, Hatspring, Immiant, Lobitos, Los Gatos, Melhorn, Morical, and Tweedy soils are 20 to 40 inches deep to bedrock. Colma soils have a mean annual soil temperature of 55 to 58 degrees F., are moderately acid in the argillic horizons, and are underlain by consolidated marine sediments at 40 to 60 inches. Facey soils are dry for less than 100 days and are underlain by a lithic contact of metamorphosed sedimentary rock. Foehlin soils are dry for 80 to 110 days, lack silica cementation within 60 inches, and are deeper than 60 inches to bedrock. Jauriga soils have 15 percent or more rock fragments throughout, have less than 27 percent clay in the control section and are underlain by weathered andesitic tuff at 40 to 60 inches. Ladd soils are dry for less than 100 days, lack silica cementation within 60 inches and are deeper than 60 inches to bedrock. Taneum are dry for 60 to 80 days, lack silica cementation within 60 inches, are influenced by loess, and are deeper than 60 inches to bedrock. Tieton soils are dry 90 to 105 days, have Bk horizons in the lower part, and are underlain by a lithic contact of andesite at 40 to 60 inches.
GEOGRAPHIC SETTING: Pittville soils are on stream terraces and toe slopes. Slopes are 0 to 30 percent. These soils formed in alluvium from extrusive igneous rock. Elevation is 3,250 to 3,550 feet. The climate is semiarid with warm dry summers and cold moist winters. Mean annual precipitation is 16 to 20 inches. Snowfall is 24 to 36 inches. The mean annual temperatures is 50 to 52 degrees F. The mean January temperature is about 30 degrees F. The mean July temperature is about 60 degrees F. Frost-free period is 120 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dudgen, Esperanza (T), Graven, and Pit soils. Dudgen soils are 10 to 20 inches deep to a hardpan in intermound areas on terraces. Esperanza soils have a fine textured argillic horizon and are in concave areas on terraces. Graven soils are 20 to 40 inches deep to a hardpan and are on mounds on terraces. Pit soils are fine textured throughout and are in basins.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderately slow permeability.
USE AND VEGETATION: This soil is mainly used for crops and livestock grazing. Some areas are used for urban development. The vegetation is mainly antelope bitterbrush, squirreltail and scattered western juniper.
DISTRIBUTION AND EXTENT: Northeastern California. The soils are not extensive. MLRA is 21.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Shasta County, Intermountain Soils Survey Area, California 1994. Source of name is from the town of Pittville.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the soil surface to 16 inches (A1, A2, Bt1)
Argillic horizon - the zone from 9 to 31 inches (Bt1, Bt2, Bt3)
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.
ADDITIONAL DATA: Reference samples of this pedon were characterized by the Lincoln Laboratory in 1983. Sample numbers are 837103, 837104 unpublished.
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.