LOCATION BOGGIANO CAEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, thermic Calcic Pachic Haploxerolls
TYPICAL PEDON: Boggiano clay loam - on nearly level slope of less than 1 percent in a walnut orchard at an elevation of 65 feet. (Colors are for dry soil unless stated. When described on April 22, 1980, the soil was moist throughout).
Ap--0 to 6 inches; dark brown (10YR 4/3) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine roots; common very fine interstitial and tubular pores; neutral (pH 7.0); clear smooth boundary. (6 to 8 inches thick)
A--6 to 14 inches; dark brown (10YR 4/3) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine, fine, medium and coarse roots; common very fine tubular and interstitial pores; neutral (pH 7.0); clear smooth boundary. (6 to 10 inches thick)
AB--14 to 23 inches; dark brown (10YR 4/3) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; common very fine tubular pores; slightly alkaline (pH 7.5); clear smooth boundary. (9 to 12 inches thick)
Bk1--23 to 39 inches; brown (7.5YR 5/4) clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine fine roots; common very fine tubular and interstitial pores; few pressure faces; slightly effervescent, lime segregated in seams; slightly alkaline (pH 7.5); gradual smooth boundary. (10 to 17 inches thick)
Bk2--39 to 48 inches; light yellowish brown (10YR 6/4) clay loam, dark brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few fine and medium roots; few very fine tubular pores; slightly effervescent, lime segregated in seams; slightly alkaline (pH 7.8); abrupt wavy boundary. (9 to 12 inches thick)
Bqkm--48 to 60 inches; light yellowish brown (10YR 6/4) strongly cemented duripan, dark brown (7.5YR 4/4) moist; massive; brittle; indurated laminar capping 1 to 2 mm thick; slightly effervescent; lime segregated in seams.
TYPE LOCATION: San Joaquin County, California; 2000 feet west and 1900 feet north of the southeast corner of Section 19; SW1/4, NW1/4, SE1/4 Section 19, T.2 N., R.7 E., MDBM.; Waterloo quadrangle.
RANGE IN CHARACTERISTICS: The mollic epipedon is 20 to 30 inches thick. Combined A and Bk thickness and depth to duripan is 40 to 60 inches. The mean annual soil temperature is 62 to 63 degrees F. The soil moisture control section between depths of 5 and 20 inches is dry in all parts from June to October unless irrigated, and moist in all parts from December to April. Fine sand or coarser is less than 15 percent. Organic matter decreases regularly with depth and is greater than 1 percent at 20 inches. Secondary lime occurs within 30 inches.
The A horizon has color of 10YR 4/2, 4/3, 5/2, 5/3; or 7.5YR 5/2 and moist color of 10YR 3/2, 3/3; or 7.5YR 3/2. The organic matter ranges from 1 to 3 percent.
The Bk horizon has color of 10YR 6/3, 6/4, 5/3, 5/4, 4/3; 7.5YR 6/4, 5/4 and moist color of 10YR 4/3, 4/4, 3/3, 3/4 or 7.5YR 4/4. Segregations of accumulated lime are in seams or soft masses. It is loam, silt loam, or clay loam with 20 to 30 percent clay.
The Bqkm horizon has color of 10YR 7/4, 6/4, 5/4 or 7.5YR 6/6, 5/4 and moist color of 10YR 4/4, 5/4; or 7.5YR 4/4.
COMPETING SERIES: This is the Cogna (T) series. Cogna soils have a combined A and Bk thickness of 30 to 40 inches and lack a duripan within 60 inches.
GEOGRAPHIC SETTING: Boggiano soils are on low fan terraces and alluvial fans. Slopes are 0 to 2 percent. The soils formed in alluvium derived dominantly from mixed rock sources. Elevations are 40 to 170 feet. The climate is subhumid with hot dry summers and cool moist winters. Dense ground fog often occurs in the winter months. Mean annual precipitation is 14 to 18 inches. The mean January temperature is 45 degrees F; the mean July temperature is 77 degrees F; and the mean annual temperature is 60 degrees F. Frost-free period is 260 to 280 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Cogna soils and the Archerdale (T), Columbia and Honcut soils. Archerdale soils have fine texture control sections on similar positions. Columbia and Honcut soils have an ochric epipedon and a coarse-loamy control section on lower positions.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used for irrigated orchard and row crops. Almonds, walnuts and cherries are the main orchard crops. Bell peppers, field beans, sugar beets and tomatoes are the main row crops. Vegetation is soft chess, wild oats, ripgut brome, turkey mullein and other annual grasses, forbs and scattered valley oaks.
DISTRIBUTION AND EXTENT: The Boggiano soils occur in the northeastern San Joaquin Valley. The soils are not extensive in MLRA-17.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: San Joaquin County, California, 1990.
REMARKS: The activity class was added to the classification in January of 2003. Competing series were not checked at that time. - ET
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface to a depth of 23 inches (Ap, A, AB horizons)
Duripan - the zone from 48 to 60 inches (Bqkm horizon)