LOCATION MANTECA CAEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, thermic Haplic Durixerolls
TYPICAL PEDON: Manteca fine sandy loam - on a 1 percent slope in a cultivated field at an elevation of 55 feet. (Colors are for dry soil unless otherwise stated). When described on June 8, 1979, the soil was moist throughout.
Ap--0 to 7 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine, fine and common medium and coarse roots; few very fine interstitial pores; strongly effervescent with disseminated lime; moderately alkaline (pH 8.0); clear smooth boundary. (5 to 7 inches thick)
A--7 to 11 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; few very fine interstitial pores; strongly effervescent with disseminated lime; moderately alkaline (pH 8.0); clear smooth boundary. (4 to 8 inches thick)
Bw--11 to 17 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; hard, friable, sticky and plastic; few very fine, fine and medium roots; common very fine and fine interstitial and tubular pores; strongly effervescent with disseminated lime; moderately alkaline (pH 8.0); clear smooth boundary. (4 to 11 inches thick)
Bk--17 to 24 inches; light brownish gray (10YR 6/2) fine sandy loam, dark grayish brown (10YR 4/2) moist; weak medium subangular blocky structure; hard, friable, sticky and plastic; few very fine, fine and medium roots; common very fine and fine interstitial and tubular pores; strongly effervescent, with lime disseminated and segregated in many large seams; moderately alkaline (pH 8.0); abrupt wavy boundary. (7 to 14 inches thick)
2Bqkm--24 to 35 inches; light gray (10YR 7/1) indurated hardpan, variegated gray (10YR 5/1) and grayish brown (10YR 5/2) moist; massive; very hard, brittle; few very fine interstitial pores; strongly effervescent with common fine filaments of lime; intermittent thin bands of a discontinuous laminar capping cemented with silica, calcium carbonate and iron; clear wavy boundary. (6 to 12 inches thick)
2Bq--35 to 54 inches; light gray (10YR 7/2) weakly and strongly cemented duripan which crushes to loam, grayish brown (10YR 5/2) moist; massive; hard, brittle; few very fine interstitial pores; moderately alkaline (pH 8.0); clear wavy boundary. (10 to 20 inches thick)
3C--54 to 74 inches; variegated light gray (10YR 7/2) and white (10YR 8/2) sandy loam, grayish brown (10YR 5/2) and light brownish gray (10YR 6/2) moist; massive; slightly hard, friable, nonsticky and nonplastic; few very fine interstitial pores; moderately alkaline (pH 8.0).
TYPE LOCATION: San Joaquin County, California about 5 miles NE of Manteca; 3,800 feet east of Jack Tone Road, 700 feet north of Lone Tree Road, 15 feet west of Farm Road; 700 feet north and 1350 feet west of the southeast corner of sec. 19, R. 8 E., T. 1 S., MDBM., Manteca quadrangle.
RANGE IN CHARACTERISTICS: Depth to duripan is 20 to 40 inches. The mean annual soil temperature varies from 62 to 63 degrees F. The soil between the depths of 5 to 20 inches is usually dry all of the time from May to November and usually moist all the rest of the year. Distinct or prominent mottles are generally present in the cemented material and are present in the lower B horizons in some pedons. The particle-size control section from a depth of 10 inches to the duripan is 10 to 18 percent clay.
The A horizon is 10YR 5/1 or 5/2. Moist color is 10YR 3/1 or 3/2. It is slightly or moderately alkaline.
The Bw and Bk horizon is 10YR 5/2, 5/4, 6/2, 6/3 or 6/4. Moist color is 10YR 4/2, 4/3, 4/4 or 3/2. It is sandy loam, fine sandy loam or loam.
The 2Bqkm and 2Bq horizon is 10YR 6/1, 7/1 or 7/2. Moist color is 10YR 5/1, 5/2, 6/1 or 6/2. It has a 1 to 5 mm thick indurated laminar capping over weakly to strongly cemented material. The laminar capping occurs intermittently with depth. Some pedons are interbedded between cemented material. The interbedded horizons have variable textures and lack cementation.
The 3C horizon is 10YR 6/1, 7/1, 7/2 or 8/2. Moist color is 10YR 5/1, 5/2, 6/1 or 6/2. It is stratified loamy sand to loam. It is slightly alkaline or moderately alkaline.
COMPETING SERIES: There are no other soils in this family.
GEOGRAPHIC SETTING: The Manteca soils are on low terraces. Slopes are 0 to 2 percent. The soils formed in alluvium from mixed rock sources. Elevations are 20 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 11 to 12 inches. Mean January temperature is 45 degrees F; mean July temperature is 77 degrees F; mean annual temperature is 60 degrees F. Frost-free period is 260 to 280 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Delhi, Honcut, Tinnin and Veritas soils. Delhi and Tinnin soils are sandy. Honcut and Veritas soils lack a duripan within 60 inches.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow runoff; moderate permeability above the cemented material. Extensive pumping of water for irrigation and for domestic use has lowered the water table in most areas to a depth of 5 feet or more. A system of reclamation projects has reduced the hazard of flooding.
USE AND VEGETATION: Soils are used for irrigated crops. Alfalfa, almonds, barley, corn, grapes, melons, pasture and tomatoes are the principal crops. Vegetation is soft chess, wild oats, ripgut brome, turkey mullein and other annual grasses, forbs and scattered valley oaks.
DISTRIBUTION AND EXTENT: Manteca soils occur in the northeastern San Joaquin Valley. The soils are of small extent in MLRA-17.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: San Joaquin County, California 1990.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface to a depth of 11 inches (Ap,A)
Cambic horizon - the zone from 11 to 17 inches (Bw)
Duripan - the zone from 24 to 54 inches (2Bkqm,2Bq).
ADDITIONAL DATA: Preliminary characterization data NSSL Nos. 79P1178- 1189. Pedon No. S79CA 077-2-1 thru 12.
The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET