LOCATION COLPIEN CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Calcic Pachic Haploxerolls
TYPICAL PEDON: Colpien loam, under irrigated cultivation, with 0 to 2 percent slopes at an elevation of 245 feet. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 6 inches; dark gray (10YR 4/1) loam, very dark gray (10YR 3/1) moist; moderate medium and coarse subangular blocky structure; hard, friable, slightly sticky and plastic; few very fine and fine roots; many very fine interstitial pores; electrical conductivity is 0.7 decisiemens per meter; sodium adsorption ratio is 3; neutral (pH 6.8); abrupt smooth boundary. (6 to 10 inches thick)
Bt1--6 to 13 inches; dark gray (10YR 4/1) clay loam, very dark gray (10YR 3/1) moist; moderate medium and coarse subangular blocky structure; hard, friable, sticky and plastic; few very fine and fine roots; common very fine interstitial and few very fine tubular pores; few thin clay films on ped faces; slightly effervescent, carbonates disseminated; electrical conductivity is 0.5 decisiemens per meter; sodium adsorption ratio is 3; slightly alkaline (pH 7.5); clear smooth boundary. (0 to 15 inches thick)
Bt2--13 to 24 inches; dark gray (10YR 4/1) clay loam, very dark gray (10YR 3/1) moist; weak coarse and moderate medium subangular blocky structure; hard, friable, sticky and plastic; common very fine interstitial and few very fine and fine tubular pores; common thin clay films bridging sand grains on ped faces and in pores; slightly effervescent, carbonates disseminated; electrical conductivity is 2.5 decisiemens per meter; sodium adsorption ratio is 5; moderately alkaline (pH 8.0); abrupt smooth boundary. (0 to 15 inches thick)
Btk1--24 to 31 inches; grayish brown (2.5Y 5/2) clay loam, dark grayish brown (2.5Y 4/2) moist; weak medium subangular blocky structure; hard, very friable, sticky and plastic; few very fine interstitial, common very fine and few fine tubular pores; common moderately thick clay films on ped faces and lining pores; strongly effervescent, carbonates disseminated and segregated as common irregularly shaped fine filaments and soft masses; electrical conductivity is 0.7 decisiemens per meter; sodium adsorption ratio is 2; moderately alkaline (pH 8.2); gradual wavy boundary. (5 to 15 inches thick)
Btk2--31 to 42 inches; light brownish gray (2.5Y 6/2) loam, dark grayish brown (2.5Y 4/2) moist; weak medium subangular blocky structure; hard, very friable, slightly sticky and plastic; few very fine interstitial, common very fine and few fine tubular pores; few moderately thick clay films on ped faces and lining pores, and few thin clay films bridging sand grains on ped faces and lining pores; few 3 to 5mm manganese concretions; strongly effervescent, carbonates disseminated and segregated as common irregularly shaped fine filaments and soft masses; electrical conductivity is 0.5 decisiemens per meter; sodium adsorption ratio is 2; few fine prominent yellowish brown (10YR 5/6) masses of iron accumulation, moist; moderately alkaline (pH 8.3); gradual wavy boundary. (5 to 15 inches thick)
Btk3--42 to 51 inches; light brownish gray (2.5Y 6/2) loam, dark grayish brown (2.5Y 4/2) moist; weak medium subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; few very fine interstitial, common very fine and few fine tubular pores; very few moderately thick clay films on ped faces and lining pores, and few thin clay films bridging sand grains on ped faces and lining pores; few 3 to 5mm manganese concretions; strongly effervescent, carbonates disseminated and segregated as few fine irregularly shaped filaments and soft masses; electrical conductivity is 0.5 decisiemens per meter; sodium adsorption ratio is 2; few fine prominent yellowish brown (10YR 5/6) masses of iron accumulation, moist; moderately alkaline (pH 8.3); clear smooth boundary. (5 to 15 inches thick)
Bt'--51 to 60 inches; light brownish gray (2.5Y 6/2) loam, dark grayish brown (2.5Y 4/2) moist; weak medium subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; few very fine, and fine tubular pores; few thin clay films bridging sand grains on ped faces and lining pores; few 3 to 5mm manganese concretions; slightly effervescent, carbonates disseminated; electrical conductivity is 0.5 decisiemens per meter; sodium adsorption ratio is 2; common fine prominent yellowish brown (10YR 5/6) masses of iron accumulation, moist; slightly alkaline (pH 7.8); abrupt smooth boundary. (0 to 12 inches thick)
C--60 to 65 inches; light brownish gray (2.5Y 6/2) sandy loam, dark grayish brown (2.5Y 4/2) moist; massive; hard, friable, slightly sticky and nonplastic; few very fine interstitial and tubular pores; electrical conductivity is 0.5 decisiemens per meter; sodium adsorption ratio is 2; few fine distinct yellowish brown (10YR 5/4) masses of iron accumulation, moist; slightly alkaline (pH 7.8).
TYPE LOCATION: Tulare County, California; about 5 miles southwest of Tulare; about 2,300 feet east and 85 feet south of the NW corner of Sec. 26, T. 20 S., R. 23 E., MDB&M; Latitude 36 degrees, 9 minutes, 30 seconds north, Longitude 119 degrees, 26 minutes, 55 seconds west; Paige Quadrangle.
RANGE IN CHARACTERISTICS:
Soil temperature: 64 to 67 degrees F.
Mollic epipedon: 20 to 40 inches thick.
Depth to carbonates: 6 to 10 inches.
Particle size control section--Clay content: 18 to 31 percent clay.
Reaction: Neutral to moderately alkaline.
Electrical conductivity: 0.5 to 4.0 decisiemens per meter.
Sodium adsorption ratio: 1 to 12.
Carbonates: Ranges from none in the upper part to few to many filaments, threads or soft masses in the subsoil. The surface 7 inches after mixing is never calcareous. In some pedons, segregated secondary carbonate occurs to 60 inches.
A horizon--10YR 4/1, 4/2, 5Y 5/1, 2.5Y 5/2 dry; and 10YR 3/1, 3/2, 5Y 3/1, 2.5Y 3/2 moist.
Clay content: 18 to 27 percent.
B horizon--10YR 4/1, 4/2, 5/2, 6/3; 2.5Y 5/2, 6/2, 6/4, 7/2; 5Y 5/1, 5/2, 6/3, 6/4; and 10YR 3/1, 3/2, 4/3; 2.5Y 3/2, 4/2, 4/4, 5/4; 5Y 3/1, 3/2, 4/3, 4/4 moist.
Texture: Loam or clay loam.
Clay content: 18 to 31 percent. The clay increase relative to the A horizon is always less than 20 percent.
C horizon--10YR 5/4, 6/4, 2.5 6/2, 6/3, 6/4; and 10YR 4/4, 2.5Y 4/2, 4/3, 4/4 moist.
Texture: Sandy loam, loam or clay loam.
Clay content: 10 to 30 percent.
Reaction: Neutral to moderately alkaline.
Other features: This horizon is absent in some pedons.
COMPETING SERIES: These are the Flamen (T-CA), Linne (CA), Pleito (CA), and San Benito (CA) series. Flamen soils have a duripan below 40 inches. Linne soils have soft bedrock at 20 to 40 inches. Pleito soils have greater than 15 percent gravel in the particle size control section. San Benito soils have soft bedrock at 40 to 60 inches and 27 to 35 percent clay throughout.
GEOGRAPHIC SETTING: Colpien soils are on terraces in alluvium derived mainly from granitic rocks. Slopes are 0 to 2 percent. Elevations are 220 to 550 feet. The climate is semiarid with hot, dry summers and cool, moist winters. The mean annual precipitation is 8 to 12 inches, the mean annual temperature is 62 to 65 degrees F., and the frost free season is to 250 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Biggriz (T), Gambogy (T), Akers (T), Nord, Tagus (T), Tujunga and Yettem soils. Biggriz, Akers and Tujunga soils lack mollic epipedons. Gambogy soils have an aquic soil moisture regime. Nord, Tagus and Yettem soils have coarse-loamy soil families.
DRAINAGE AND PERMEABILITY: Moderately well drained; runoff is negligible to low; moderately slow permeability due to high content of mica in the soil.
USE AND VEGETATION: This soil is used for irrigated cropland to grow cotton, corn, wheat, grapes, stone fruits, walnuts and alfalfa. It is also used for dairy and cattle production and building site development.
DISTRIBUTION AND EXTENT: Southern San Joaquin Valley, California. The soil is moderately extensive. MLRA 17
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Tulare County, West Part, California, 1999.
REMARKS: The name is from a local road. Type location was changed to another location in 1992 and classification was changed from Cumulic to a Calcic Pachic subgroup.
ADDITIONAL DATA:
1.0 Mollic epipedon--The zone from the soil surface to a depth of about 24 inches (Ap, Bt1, Bt2 horizons).
2.0 Organic matter--Is assumed to be 1 to 3 percent in the upper 24 inches of the soil and to decrease regularly with increasing depth.
3.0 Fine-loamy family--The soil has 18 to 31 percent clay in the 10 to 40 inch particle size control section.
4.0 Bt Horizon--Due to the presence of clay films we use the small "t" subscript on the B horizon, but the soil lacks the clay increase needed for an argillic horizon.