LOCATION VIGNOLO CAEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, thermic Haplic Durixerolls
TYPICAL PEDON: Vignolo silty clay loam - on a nearly level slope of less than 1 percent under cultivated kidney beans at an elevation of 45 feet. (Colors are for dry soil unless otherwise stated. When described on October 9, 1980, the soil was moist throughout).
Ap--0 to 4 inches; brown (10YR 5/3) silty clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium angular blocky structure; hard, friable, sticky and plastic; few very fine and fine roots; few very fine interstitial pores; slightly alkaline (pH 7.5); clear smooth boundary. (2 to 6 inches thick)
A--4 to 14 inches; dark grayish brown (10YR 4/2) silty clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium angular blocky structure; hard, friable, sticky and plastic; common very fine roots; few very fine tubular pores; slightly alkaline (pH 7.5) clear smooth boundary. (5 to 10 inches thick)
Bw--14 to 18 inches; brown (10YR 5/3) clay loam, dark brown (10YR 3/3) moist; many fine very dark gray (10YR 3/1) manganese stains; moderate medium angular blocky structure; hard, friable, sticky and plastic; few very fine roots; few very fine tubular pores; slightly alkaline (pH 7.5) clear wavy boundary. (4 to 10 inches thick)
Bk--18 to 30 inches; variegated brown (10YR 5/3) and pale brown (10YR 6/3) clay loam, dark brown (10YR 3/3) and brown (10YR 4/3) moist; many fine very dark gray (10YR 3/1) manganese stains; moderate medium angular blocky structure; hard, friable, sticky and plastic; few very fine roots; common very fine tubular pores; slightly effervescent with disseminated lime and few fine soft masses of lime; weakly cemented in 25 percent of matrix; slightly alkaline (pH 7.5) abrupt wavy boundary. (8 to 14 inches thick)
Bqkm--30 to 33 inches; indurated duripan with 1 to 4 mm thick laminar capping; violently effervescent with disseminated lime and common fine seams of lime; cementing agents are silica, iron and calcium carbonate; moderately alkaline (pH 8.0); abrupt wavy boundary. (1 to 3 inches thick).
Bkq--33 to 60 inches; light gray (10YR 7/2), very pale brown (10YR 7/3) and pale brown (10YR 6/3) strongly cemented duripan, dark brown (10YR 4/3), dark yellowish brown (10YR 4/4) and dark reddish brown (5YR 3/2, 3/3) moist; massive; brittle; strongly cemented in 75 percent of the matrix, weakly cemented in the remainder; violently effervescent with disseminated lime and common fine seams of lime; cementing agents are silica, iron and calcium carbonate; moderately alkaline (pH 8.0).
TYPE LOCATION: Typical pedon of Vignolo silty clay loam, 0 to 2 percent slopes, 1,500 feet east of Ashley road and 1,200 feet north od Highway 88; 38 degrees 00' 55'' north lat., 121 degrees 12' 46'' west long. (in an unsectionized area) Waterloo quadrangle.
RANGE IN CHARACTERISTICS: Depth to duripan is 20 to 40 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 and moist in all parts from December to April. The percent of fine sand or coarser is less than 15 percent, typically about 5 percent. Disseminated or segregated lime occurs at a depth of 20 or more 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 2 percent. It is silty clay loam or loam.
The Bw and Bk horizon has color of 10YR 6/3, 6/4, 5/2, 5/3, 5/4, 4/3; 7.5YR 6/4 or 5/4 and moist color of 10YR 4/3, 3/2, 3/3, 3/4; or 7.5YR 4/4. It is loam, silt loam, silty clay loam or clay loam.
The Bqkm horizon is strongly cemented to indurated in the laminar capping and strongly cemented in the underlying material. It has dry color of 10YR 7/3, 7/2, 6/4, 6/3, 5/3; 7.5YR 6/6, 6/4, 5/6 or 5/4. The primary cementing agent is silica and contains accessory cementing elements of iron and calcium carbonate.
COMPETING SERIES: There are no other soils in this family.
GEOGRAPHIC SETTING: Vignolo soils are on low fan terraces and alluvial fans. Slopes are 0 to 2 percent. The soils formed in alluvium from mixed rock sources. Elevations are 40 to 110 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 13 to 15 inches. The mean January temperature is 45 degrees F; mean July temperature is 77 degrees F; and mean annual temperature is 60 degrees F. Frost-free period is 260 to 280 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Archerdale and Hollenbeck soils. Archerdale soils are fine. Hollenbeck soils have intersecting slickensides and has 40 to 60 percent clay in the upper 40 inches.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used for irrigated cropland to grow orchards, row crops and field crops. Walnuts and cherries are the main orchard crops. Beans, peppers and tomatoes are the main row crops. Alfalfa and small grains are the main field crops. Vegetation is soft chess, wild oats, ripgut brome, turkey mullein and other annual grasses, forbs and scattered valley oaks.
DISTRIBUTION AND EXTENT: Vignolo 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 February 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 14 inches (Ap,A)
Cambic horizon - the zone from 14 to 18 inches (Bw)
Duripan - the zone from 30 to 60 inches (Bkq)
Haplic subgroup - lacks an argillic horizon above the duripan.