LOCATION CENTERVILLE CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Aridic Calcixererts
TYPICAL PEDON: Centerville clay, oat hay. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 12 inches; dark grayish brown (10YR 4/2) clay, dark brown (10YR 3/3) moist; massive (1/4 to 1/2 inch of strong fine granular structure at the top of the Ap); very hard, firm, very sticky and very plastic; many very fine roots mostly concentrated in the cracks; many very fine pores; moderately alkaline (pH 8.0); gradual smooth boundary. (4 to 12 inches thick)
Bss--12 to 18 inches; dark grayish brown (10YR 4/2) clay, dark brown (10YR 3/3) moist; massive; very hard, firm, very sticky and very plastic; many very fine roots; many very fine pores; many intersecting slickensides; moderately alkaline (pH 8.0); clear smooth boundary. (3 to 7 inches thick)
Bkss1--18 to 23 inches; brown (7.5YR 4/2) clay, dark brown (7.5YR 3/2) moist; few spots of reddish brown (5YR 5/4) moist; massive; very hard, firm, very sticky and very plastic; many very fine roots; many very fine pores; few dark grayish brown streaks from Ap horizon extends through this horizon; many intersecting slickensides; slightly effervescent in matrix and strongly effervescent in common soft carbonate masses; moderately alkaline (pH 8.0); clear smooth boundary. (3 to 5 inches thick)
Bkss2--23 to 30 inches; brown (7.5YR 4/2) and reddish brown (5YR 5/4) clay dark brown (7.5YR 3/2) and reddish brown (5YR 4/4) moist; massive; very hard, firm, very sticky and very plastic; common very fine roots; many very fine pores; few dark grayish brown streaks from Ap horizon extends through this horizon; many intersecting slickensides; slightly effervescent in the matrix and strongly effervescent in the common soft carbonate masses; moderately alkaline (pH 8.2); clear smooth boundary. (5 to 8 inches thick)
Bk--30 to 37 inches; reddish brown (5YR 5/4) sandy clay, brown (7.5YR 4/4) moist; massive; very hard, firm, sticky and very plastic; common very fine roots; many very fine pores; few dark grayish brown streaks (1/4 to 2.5 cm wide) from Ap horizon extends 4 inches into this horizon; strongly effervescent in matrix and violently effervescent in common soft carbonate masses (1 to 5 cm); moderately alkaline (pH 8.2); clear wavy boundary. (5 to 8 inches thick)
2Btkd--37 to 54 inches; brown (7.5YR 5/4) sandy clay loam, dark brown (7.5YR 4/4) moist; massive; hard, firm, sticky and plastic; many fine tubular pores; common thin clay films bridging sand grains and lining pores; strongly effervescent, carbonates disseminated and violently effervescent, carbonates segregated as common fine irregular masses; moderately alkaline (pH 8.0).
TYPE LOCATION: Tulare County, California; about 2 miles north of Ducor; 1,400 feet west of Road 264 and 1,450 feet north of Avenue 72; NW1/4 SE1/4 section 18, T. 23 S., R. 28 E.; Fountain Springs Quadrangle.
RANGE IN CHARACTERISTICS:
The mean annual soil temperature is 61 to 67 degrees F.
The soil between depths of 4 to 12 inches is usually dry all of the time from about May 15 until November 15 or early December and is moist in some part or all parts all the rest of the year.
The soil has cracks 1 cm wide or more and cracks extend from the surface to a depth of 20 inches or more when dry.
The A horizon is 10YR 3/2, 4/2, 4/3, 4/4, 5/2, 5/3; 7.5YR 3/2, 4/2, 5/3, 5/4; 5YR 3/2, 3/3, 3/4, 4/2, 4/3, 4/4, 5/3, 5/4 dry. Moist colors are 10YR 2/2, 3/2, 3/3; 7.5YR 3/2, 4/2; 5YR 3/2, 3/3, 4/2.
This horizon has few to many intersecting slickensides.
Reaction is slightly acid to moderately alkaline.
The Bss, Bkss and Bk horizons are 10YR 4/3, 4/4, 5/2, 5/3, 6/2; 7.5YR 3/2, 4/2, 4/4, 4/6, 5/2, 5/4, 5/6; 5YR 4/3, 4/4, 3/2, 3/3, 3/4, 4/2, 5/3. Moist 10YR 3/2, 3/3, 3/4, 4/2, 4/3; 7.5YR 3/2, 3/4, 4/2, 4/4, 4/6; 5YR 5/4, 4/4, 4/2, 3/3, 3/2. These horizons are clay loam, clay or sandy clay with 35 to 60 percent clay.
It has common or many intersecting slickensides in at least some part.
These horizons are slightly or strongly effervescent in the matrix and strongly or violently effervescent in the segregated carbonates.
Reaction is slightly or moderately alkaline.
Btkss horizons also occur in some pedons.
The 2Btkd horizon 10YR 4/3, 4/4, 5/2, 5/3, 6/2, 6/4; 7.5YR 3/2, 4/2, 4/4, 4/6, 5/2, 5/4, 5/6; 5YR 4/3, 4/4, 3/2, 3/3, 3/4, 4/2, 5/3. Moist 10YR 3/2, 3/3, 3/4, 4/2, 4/3, 5/2, 5/4, 5/6; 7.5YR 3/2, 3/4, 4/2, 4/4, 4/6; 5YR 5/4, 4/4, 4/2, 3/3, 3/2.
It is composed of dense granitic alluvial material that is stratified sandy loam to gravelly clay, with 0 to 35 percent gravel.
COMPETING SERIES: These are no competing soils in this family.
GEOGRAPHIC SETTING: Centerville soils are on fans and dissected stream terraces at elevations of 300 to 850 feet. Slope ranges from 0 to 30 percent. The soils formed in alluvium mainly from granitic sources. The climate is dry subhumid mesothermal with hot, dry summers and cool, moist winters. The mean annual precipitation is 9 to 12 inches. The average January temperature is 46 degrees F.; the average July temperature is 81 degrees F; and the mean annual temperature is 59 to 65 degrees F. The frost free season is 250 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Exeter and Yokohl soils. Exeter and Yokohl soils have a duripan at depths of 20 to 40 inches.
DRAINAGE AND PERMEABILITY: Well drained; negligible to very high runoff due to range of slope; slow permeability.
USE AND VEGETATION: Irrigated oranges, and dryland barley, wheat and rangeland. Native vegetation in nonfarmed areas is mainly annual grasses and forbs. Citrus plantings have taken advantage of the thermal belt position offered by these soils.
DISTRIBUTION AND EXTENT: Eastern side of San Joaquin Valley. The soils are extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Fresno County, California, 1912.
REMARKS: The Ducor series surveyed in previous soil surveys is now recognized as Centerville series. This soil originally was described as having a paralithic contact. In re-examining the type location, it was found that no paralithic contact existed. It is likely that there is a paralithic contact in this soil where mapped in Tulare Central Part Soil Survey on slopes greater than 15 percent (hill landforms) with granitic parent material. This will need to be re-evaluated in Tulare Central Part Soil Survey at a later date.
Series reclassified on July, 1998.