LOCATION CALLA CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Typic Calcixerepts
TYPICAL PEDON: Calla clay loam, on an east-facing slope of 9 percent, under soft chess, filaree and other annual grasses and forbs at an elevation of 520 feet. (When described on March 31, 1983, the soil moist throughout. Colors are for dry soil unless otherwise stated.)
A--0 to 5 inches; light brownish gray (2.5Y 6/2) clay loam, dark grayish brown (2.5Y 4/2) moist; moderate medium subangular blocky structure; hard, friable, sticky and plastic; many very fine roots; few very fine tubular pores; strongly effervescent with disseminated lime and common fine irregular soft masses of lime; moderately alkaline (pH
8.0); clear smooth boundary. (4 to 12 inches thick)
Bk1--5 to 11 inches; light brownish gray (10YR 6/2) clay loam, dark grayish brown (10YR 5/2) moist; moderate medium subangular blocky structure; very hard, firm, very sticky and very plastic; common very fine roots; few very fine tubular pores; violently effervescent with disseminated lime and common fine irregular soft masses of lime; moderately alkaline (pH 8.0); abrupt wavy boundary. (5 to 10 inches thick)
Bk2--11 to 19 inches; light brownish gray (10YR 6/2) and grayish brown (10YR 5/2) clay loam, dark grayish brown (2.5Y 4/2) moist; moderate medium subangular blocky structure; hard, friable, very sticky and very plastic; few very fine roots; few very fine tubular pores; violently effervescent with disseminated lime and many medium irregular soft masses of lime; moderately alkaline (pH 8.2); abrupt wavy boundary. (7 to 9 inches thick)
Bk3--19 to 29 inches; light gray (2.5Y 7/2) and light brownish gray (2.5Y 6/2) clay loam, grayish brown (2.5Y 5/2) and dark grayish brown (2.5Y 4/2) moist; moderate medium subangular blocky structure; hard, very friable, very sticky and very plastic; violently effervescent with disseminated lime and many medium seams and irregular soft masses of lime; moderately alkaline (pH 8.2); abrupt wavy boundary. (8 to 15 inches thick)
Bk4--29 to 37 inches; white (2.5Y 8/2) and light gray (2.5Y 7/2) clay loam, grayish brown (2.5Y 5/2) moist; moderate medium subangular blocky structure; hard, very friable, sticky and plastic; violently effervescent with disseminated lime and common fine irregular soft masses of lime; moderately alkaline (pH 8.0); clear wavy boundary. (8 to 10 inches thick)
Bk5--37 to 52 inches; light gray (2.5Y 7/2) clay loam, light brownish gray (2.5Y 6/2) and grayish brown (2.5Y 5/2) moist; moderate medium subangular blocky structure; hard, very friable, sticky and plastic; violently effervescent with disseminated lime and common fine irregular soft masses of lime; moderately alkaline (pH 8.0); clear wavy boundary. (12 to 16 inches thick)
Bk6--52 to 60 inches; light gray (10YR 7/2) clay loam, brown (10YR 5/3) moist; moderate medium subangular blocky structure; hard, very friable, sticky and plastic; violently effervescent with disseminated lime and common fine irregular soft masses of lime; moderately alkaline (pH 8.0).
TYPE LOCATION: San Joaquin County, California; about 8 miles south of Tracy, 1,150 feet north and 2,200 feet east of the southwest corner of sec. 29, T.3 S., R.5 E., Tracy quadrangle.
RANGE IN CHARACTERISTICS: Combined thickness of the A and Bk horizons is 60 inches or more. The mean annual soil temperature is 62 degrees to 63 degrees F. The soil between the depths of 6 and 18 inches is dry in all parts from May through October and moist in all parts between late December and mid March. Few to many fine or medium soft masses or filaments of lime are present throughout. Content of gravel is 0 to 10 percent. It is slightly alkaline or moderately alkaline throughout.
The A horizon is 10YR 6/1, 6/2, 6/3; 2.5Y 5/2 or 6/2. Moist color is 10YR 4/2, 4/3; 2.5Y 4/2 or 5/2.
The Bk horizon is 10YR 5/2, 5/3, 6/2, 6/3, 6/4, 7/2, 7/3, 8/2 or 2.5Y 6/2. Moist color is 10YR 4/2, 4/3, 5/2, 5/3, 5/4; 2.5Y 4/2, 5/2 or 6/2. Calcium carbonate equivalent is 15 to 25 percent in some part and decreases to 5 to 10 percent below.
COMPETING SERIES: These are the Balcom (CA), Biggriz (T CA), Chanac (CA), Chaqua (CA), Checker (CA), Exclose (T CA), and Vernalis (CA) series. Balcom soils have a paralithic contact at a depth of 23 to 40 inches. Biggriz and Chanac soils have more than 20 percent very coarse plus coarse sand. Chaqua soils have a Btk horizon and have 7.5YR hues. Checker soils have an exchangeable sodium percentage of greater 40 in the upper 36 inches and are somewhat poorly drained. Vernalis soils do not have a calcic horizon.
GEOGRAPHIC SETTING: Calla soils are on dissected and uplifted terraces and have slopes of 2 to 50 percent. They formed in calcareous alluvium from sedimentary sources. Elevations range from 300 to 1,500 feet. The climate is semi-arid with hot dry summers and cool moist winters. The average annual precipitation is 9 to 13 inches. The mean January temperature is 45 degrees F; mean July temperature is 78 degrees F; and the mean annual temperature is 60 to 62 degrees F. The frost-free season is 250 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Capay, Carbona, San Timoteo and Wisflat soils. The Capay soils are fine textured on alluvial fans and interfan basins. The Carbona soils are fine textured on similar positions. The San Timoteo and Wisflat soils have less 18 percent clay and are on hills.
DRAINAGE AND PERMEABILITY: Well drained; low to high runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used for livestock grazing. Where irrigation water is available, they are used for irrigated orchards. The natural vegetation is annual grasses and forbs such as soft chess, filaree, foxtail fescue, wild oats, red brome.
DISTRIBUTION AND EXTENT: These soils are on terraces of the eastern edge of the Coast Range foothills and the western edge of the Central San Joaquin Valley. They are not extensive in MLRA-17.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES PROPOSED: San Joaquin County, California, 1990.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surface to a depth of 5 inches (A).
Calcic horizon - the zone from 11 to 29 inches (Bk2,Bk3)
15 to 20 percent calcium carbonate equivalent (Calcium Carbonate Equivalent Field Kit).
Runoff terminology adjusted 4/96 to adjective criteria of the Soil Survey Manual, 10/93
CEC/Clay ratio estimated from similar soils with laboratory data in the W. Stanislaus Soil Survey Area.