LOCATION CORONA CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, thermic Pachic Argixerolls
TYPICAL PEDON: Corona silt loam, on a slope of 1 percent under a walnut orchard at 260 feet elevation. (Colors are for dry soil unless otherwise stated. When described on 9/5/74 the soil was moist throughout.)
A1p--0 to 7 inches; gray (10YR 5/1) silt loam, very dark gray (10YR 3/1) moist; moderate coarse subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; many fine and medium roots; common fine tubular pores; slightly effervescent; moderately alkaline (pH 8.0); abrupt wavy boundary. (6 to 8 inches thick)
A12--7 to 25 inches; grayish brown (10YR 5/2) silt loam, very dark gray (10YR 3/1) moist; common fine distinct dark brown (7.5YR 3/2) mottles; moist; moderate coarse subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common fine and medium roots common very fine and fine tubular pores; slightly effervescent; slightly alkaline (pH 7.8); abrupt smooth boundary. (18 to 20 inches thick)
B21t--25 to 34 inches; gray (10YR 5/1) silty clay loam, very dark gray (10YR 3/1) moist; moderate medium subangular blocky structure; very hard, firm, sticky and plastic; common very fine and fine roots; thin clay films in pores and on peds; few rounded manganese concretions 0.5 to 2 mm in diameter; slightly effervescent, lime in seams; slightly alkaline (pH 7.5); abrupt wavy boundary. (6 to 11 inches thick)
B22t--34 to 42 inches; grayish brown (10YR 5/2) silty clay loam, very dark gray and dark brown (10YR 3/1, 3/3) moist; moderate medium subangular blocky structure; very hard, firm, sticky and plastic; few fine roots; many very fine and fine tubular pores; few thin clay films in pores and on peds; few rounded manganese concretions 0.5 to 2 mm in diameter; slightly effervescent, lime in seams; slightly alkaline (pH 7.5); abrupt wavy boundary. (7 to 10 inches thick)
B3tca--42 to 55 inches; pale brown (10YR 6/3) heavy loam, dark brown (10YR 3/3) moist; massive; very hard, firm, sticky and plastic; few fine roots; many very fine and fine tubular pores; few thin clay films in pores and on peds; strongly effervescent, lime in seams; slightly alkaline (pH 7.5); abrupt smooth boundary. (18 to 24 inches thick)
C1--55 to 64 inches; light yellowish brown (10YR 6/4) heavy sandy loam, dark brown (10YR 4/3) moist; massive; very hard, friable, sticky and plastic; many very fine tubular pores; neutral (pH 7.0); abrupt smooth boundary. (8 to 10 inches thick)
2--64 to 76 inches; light yellowish brown (10YR 6/4) sandy loam, dark brown (10YR 3/3) moist; massive; hard, very friable, slightly sticky and slightly plastic; many very fine and fine tubular pores; neutral (pH 7.0); abrupt smooth boundary.
TYPE LOCATION: Kings County, California; northeast of the City of Hanford, in an old walnut orchard, about 0.4 mile south of Dover Avenue and 30 feet west of 9th Avenue; in the SE1/4 SE1/4 NE1/4 section 31, T. 17 S., R. 22 E., MDB&M.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 61 degrees to 63 degrees F. The soil between the depths of 6 to 18 inches is usually moist in all parts from January 1 to April 15. It is dry in all parts from July 15 to mid November. The organic matter is more than 1 percent to a depth of 25 inches and decreases regularly with increasing depth.
The A horizon has dry color of 10YR 5/1, 5/2, and 4/2 and moist color of 10YR 3/1 or 3/2. This horizon is slightly alkaline or moderately alkaline.
The B2t horizon has dry color of 10YR 5/1 or 5/2 and moist color of 10YR 3/1 or 3/2. It has 27 to 35 percent clay. It is mildly alkaline or moderately alkaline and is slightly or strongly effervescent. It is neutral or slightly alkaline.
COMPETING SERIES: These are the Arujo, Botella, Elkhorn, Havala, Lockwood, and McCoy series. These soils are well drained and noneffervescent, in all parts.
GEOGRAPHIC SETTING: Corona soils are on flood plains and alluvial fans. Slopes are 0 to 2 percent. Elevations are 200 to 400 feet. The climate is semiarid and has hot, dry summers and cool, foggy and moist winters. The average annual precipitation ranges from 8 to 12 inches. The mean January temperature is about 45 degrees F. and the mean July temperature is about 81 degrees F. The mean annual temperature is 62 degrees F. The frost-free season ranges from 250 to 275 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Nord, Whitewolf, Kimberlina, and Wasco soils. Nord soils lack an argillic horizon and have an irregular decrease in organic carbon with increasing depth. Whitewolf soils have a sandy control section and an ochric epipedon. Kimberlina and Wasco soils have an ochric epipedon and an aridic moisture regime.
DRAINAGE AND PERMEABILITY: Moderately well drained; medium runoff; slow permeability.
USE AND VEGETATION: Corona soils are cultivated. The natural vegetation was annual grasses, forbs, and valley oaks (Quercus lobata Nee). Corona soils are used for such crops as irrigated alfalfa, cotton, corn, milo, barley, wheat, sugar beets, tomatoes, grapes, walnuts, peaches and other fruit and nut trees.
DISTRIBUTION AND EXTENT: San Joaquin Valley. Corona is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Kings County, California, 1980.
REMARKS: The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET