LOCATION ALTASLOUGH CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, calcareous, thermic Typic Endoaquolls
TYPICAL PEDON: Altaslough clay loam, 0 to 1 percent slopes, under rotated cotton, sugar beets, and alfalfa. The elevation is 162 feet. (Colors are for dry soil unless otherwise noted. When described on March 15, 1994, the soil was moist throughout.)
Ap1--0 to 13 inches; dark gray (5Y 4/1) clay loam, black (5Y 2/1) moist; weak and moderate medium and coarse subangular blocky structure; very hard, extremely firm, moderately sticky and moderately plastic; moderately few very fine to medium roots throughout; many very fine and fine and moderately few medium tubular and interstitial pores; few (1 percent), fine recent redoximorphic masses of iron accumulation lining pores; slightly effervescent, carbonates disseminated and segregated as few (1 percent), irregular, medium hard carbonate concretions, that dissolve in acid, with accessory recent redoximorphic iron and manganese accumulations; electrical conductivity is 2.2 decisiemens per meter; sodium adsorption ratio is 13; moderately alkaline (pH 7.9); clear smooth boundary.
Ap2--13 to 24 inches; 70 percent dark gray (5Y 4/1) and 30 percent light olive gray (5Y 6/2) clay loam, 70 percent black (5Y 2/1) moist and 30 percent olive gray (5Y 5/2) moist; weak medium subangular blocky structure; very hard, extremely firm, moderately sticky and moderately plastic; common very fine and few fine and medium roots throughout; many very fine and fine and moderately few medium tubular and interstitial pores; slightly effervescent with disseminated carbonates in dark gray (5Y 4/1) matrix, and strongly effervescent with disseminated carbonates in dark gray (5Y 4/1) matrix, and segregated in light olive gray (5Y 6/2) matrix as few (1 percent), fine, irregular carbonate threads and as few (1 percent), medium, irregular hard carbonate concretions, that dissolve in acid, with accessory recent redoximorphic iron and manganese accumulations; electrical conductivity is 8.1 decisiemens per meter; sodium adsorption ratio is 9; moderately alkaline (pH 7.9); abrupt smooth boundary. (The combined thickness of the Ap1 and Ap2 horizons is 15 to 26 inches)
Bknzg1--24 to 36 inches; light olive gray (5Y 6/2) clay loam, olive gray (5Y 5/2) moist; matrix changes color on exposure to air; moderate medium subangular blocky structure; extremely hard, very firm, moderately sticky and moderately plastic; moderately few very fine roots throughout; common fine and common very fine tubular and interstitial pores; common (2 percent) irregular, fine, prominent, yellowish brown (10YR 5/8) moist recent redoximorphic masses of iron accumulation in the matrix; strongly effervescent, carbonates disseminated and segregated as common (3 percent), irregular, fine carbonate threads and soft masses and as common (5 percent), irregular, fine and medium hard carbonate concretions, that dissolve in acid, with accessory recent redoximorphic iron and manganese accumulations; electrical conductivity is 5.4 decisiemens per meter; sodium adsorption ratio is 25; moderately alkaline (pH 8.0); clear smooth boundary.
Bknzg2--36 to 45 inches; light gray (5Y 7/2) clay loam, olive gray (5Y 5/2) moist; matrix changes color on exposure to air; weak medium subangular blocky structure; extremely hard, very firm, moderately sticky and moderately plastic; very few very fine and fine roots between peds matted along faces of concretions; common fine and common very fine tubular and interstitial pores; common (2 percent), irregular, fine, prominent, yellowish brown (10YR 5/8) moist recent redoximorphic masses of iron accumulation in the matrix; few (1 percent), cylindrical, fine and medium recent iron depletions lining pores; strongly effervescent, carbonates disseminated and segregated as common (8 percent), irregular, fine carbonate threads and soft masses and as common (10 percent), dendritic, medium and coarse hard carbonate concretions, that dissolve in acid, with accessory recent redoximorphic iron and manganese accumulations; electrical conductivity is 9.9 decisiemens per meter; sodium adsorption ratio is 54; moderately alkaline (pH 8.2); clear smooth boundary.
Bknzg3--45 to 51 inches; light gray (5Y 7/2) clay loam, olive gray (5Y 5/2) moist; matrix changes color on exposure to air; moderate medium subangular blocky structure; extremely hard, extremely firm, moderately sticky and moderately plastic; very few very fine roots between peds matted along faces of concretions; common very fine and fine tubular and interstitial pores; common (2 percent), irregular, fine, prominent, yellowish brown (10YR 5/8) moist recent redoximorphic masses of iron accumulation in the matrix; strongly effervescent, carbonates disseminated and segregated as common (10 percent), irregular, medium and coarse hard carbonate concretions, that dissolve in acid, and many (40 percent), dendritic, coarse and very coarse hard carbonate concretions, that dissolve in acid, surrounding redox depletions with accessory recent redoximorphic iron and manganese accumulations; electrical conductivity is 5.1 decisiemens per meter; sodium adsorption ratio is 34; moderately alkaline (pH 8.3); abrupt smooth boundary. (The combined thickness of the Bkng1, Bkng2 and Bkng3 horizons is 10 to 30 inches)
2Bknzg4--51 to 64 inches; pale yellow (5Y 7/3) loam, olive (5Y 5/3) moist; weak fine subangular blocky structure; extremely hard, firm, slightly sticky and slightly plastic; common medium tubular and interstitial pores; many (60 percent), irregular, medium, prominent, brownish yellow (10YR 6/8) moist recent redoximorphic masses of iron accumulation in the matrix; few (1 percent), cylindrical, fine and medium recent iron depletions lining pores; slightly effervescent, carbonates disseminated and segregated as common (20 percent) dendritic, medium, coarse, and very coarse hard carbonate concretions, that dissolve in acid, surrounding redox depletions with accessory recent iron and manganese accumulations; electrical conductivity is 10.9 decisiemens per meter; sodium adsorption ratio is 60; strongly alkaline (pH 8.5); abrupt smooth boundary. (10 to 18 inches thick)
2Bknzg5--64 to 72 inches; light gray (5Y 7/2) fine sandy loam, light brownish gray (2.5Y 6/2) moist; massive; very hard, firm, slightly sticky and slightly plastic; common medium tubular and interstitial pores; many (60 percent), irregular, medium, prominent, brownish yellow (10YR 6/8) moist recent redoximorphic masses of iron accumulation in the matrix; common (2 percent), fine, irregular mica flakes throughout; slightly effervescent, carbonates disseminated and segregated as common (10 percent), dendritic, medium and coarse hard carbonate concretions, that dissolve in acid, surrounding redox depletions with accessory recent redoximorphic iron and manganese accumulations; electrical conductivity is 11.0 decisiemens per meter; sodium adsorption ratio is 60; moderately alkaline (pH 8.1).
TYPE LOCATION: Fresno County, California; approximately 0.4 mile northwest of the community of Tranquillity; approximately 345 feet south of Jefferson Avenue, 186 feet west of a canal, and 700 feet east of the intersection of Amador and Jefferson Avenues; approximately 2,295 feet north and 700 feet east of the southwest corner of section 5, T. 15 S., R. 16 E., MDB&M; Latitude 36 degrees, 39 minutes, 12 seconds north and Longitude 120 degrees, 15 minutes, 29 seconds west; USGS Tranquillity Topographic Quadrangle, NAD 27.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 64 to 66 degrees F. The thickness of the mollic epipedon ranges from 10 to 20 inches. Organic matter content is 1 to 2 percent in the mollic epipedon, and it decreases regularly to less than 1 percent below a depth of 20 inches. Depth to a calcic horizon is 15 to 26 inches. It is saline-sodic below the A horizon, and the electrical conductivity and sodium adsorption ratio increase with depth. Gypsum may occur in all horizons, and its presence is dependent on reclamation practices.
The Ap horizon has color of 10YR 4/2; 5Y 4/1, 5/1, 5/2 or 6/2. Moist color is 10YR 3/2; 5Y 2/1, 3/1, 3/2 or 5/2. Dry color value of 6 and moist color value of 5 occur below the mollic epipedon. Clay content is 27 to 35 percent. Calcium carbonate equivalent is 1 to 5 percent. Electrical conductivity is 2 to 16 decisiemens per meter. Sodium adsorption ratio is 5 to 20. Reaction is slightly alkaline or moderately alkaline.
The Bknzg calcic horizon has color of 5Y 5/2, 6/2, 7/2 or 7/3. Moist color is 5Y 4/2, 4/4, 5/2, 5/3 or 5/6. Clay content is 27 to 35 percent. Calcium carbonate equivalent is 15 to 30 percent. Electrical conductivity is 4 to 16 decisiemens per meter. Sodium adsorption ratio is 20 to 60. Distinct or prominent redoximorphic features are present. Reaction is moderately alkaline or strongly alkaline.
The 2Bknzg horizon, below the calcic horizon, has color of 2.5Y 5/3, 6/3, 7/2, 7/3; 5Y 5/3, 6/3, 7/2 or 7/3. Moist color is 2.5Y 4/2, 4/4, 5/2, 5/3, 6/2; 5Y 4/4, 5/3 or 6/2. Texture is stratified sandy loam, fine sandy loam, loam or clay loam. Clay content is 15 to 35 percent. Calcium carbonate equivalent is 5 to 10 percent. Electrical conductivity is 8 to 16 decisiemens per meter. Sodium adsorption ratio is 30 to 80. Distinct or prominent redoximorphic features are present. Reaction is moderately alkaline or strongly alkaline.
COMPETING SERIES: There are no competing series at this time.
GEOGRAPHIC SETTING: Altaslough soils are on flood plains and basin floors. The soils formed in mixed alluvium derived dominantly from igneous rock. Slope is 0 to 1 percent. Elevation is 115 to 165 feet. The climate is semiarid with hot dry summers and cool moist winters. Mean annual precipitation is 7 to 8 inches; mean January temperature is about 44 degrees F.; mean July temperature is about 81 degrees F; mean annual temperature is 62 to 64 degrees F. Frost-free season is 240 to 270 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Armona, Calflax, Ciervo, Lillis, Gepford, Tachi, and Tranquillity series. Armona and Calflax soils have an irregular decrease in organic carbon content with depth. Ciervo, Gepford and Tranquillity soils have a fine particle-size control section. Lillis and Tachi soils have a very fine particle-size control section. Armona, Gepford and Tachi soils are on flood plains and basin floors. Calflax, Ciervo, Lillis and Tranquillity soils are on fan skirts.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; medium runoff; slow permeability. Altaslough soils were favored by Native Americans for encampments, as evidenced by findings of cultural artifacts, due to their location at slightly higher elevations along the Fresno Slough. They are considered to be drained because of the presence of dams and reservoirs in the Sierra Nevada, pumping from the water table, use of tile and interceptor drains and the filling and leveling of the sloughs in the vicinity. They are protected from major flooding by large flood control levees and reservoirs.
USE AND VEGETATION: Most areas of these soils are cultivated and irrigated. They are principally used for field crops and vegetable production with small acreages of orchards and pastures.
DISTRIBUTION AND EXTENT: These soils are near the Fresno Slough in the central part of the San Joaquin Valley in California. They are not extensive. MLRA 17.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Fresno County, California, 2002.
REMARKS: Named after the 'Alta,' a stern wheel steamer, which in 1862 on an exploratory voyage from San Francisco to Tulare Lake ran permanently aground in the vicinity of Fresno Slough.
Major Diagnostic Horizons:
Mollic epipedon - 13 inches thick.
Calcic horizon - A calcic horizon with 15 to 26 percent calcium carbonate occurs at a depth of 24 to 51 inches.
Calcareous class - Effervesces throughout the 10 to 20 inch control section.
Particle size class - Fine-loamy with an average of 27 to 35 percent clay in the 10 to 40 inch control section.
Aquic moisture regime - Formed under aquic conditions, but now drained and protected. Redox concentrations, depletions, and reduced matrix from the lower part of the mollic epipedon to a depth of 80 inches from the mineral soil surface.