LOCATION PINTO CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Typic Argixerolls
TYPICAL PEDON: Pinto loam, pasture. (Colors are for dry soil unless otherwise noted.)
A1--0 to 14 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate coarse subangular blocky and moderate fine and medium granular structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine and fine tubular pores; moderately acid (pH 5.8); clear wavy boundary. (10 to 16 inches thick)
A2--14 to 21 inches; light brownish gray (10YR 6/2) loam, very dark grayish brown (10YR 3/2) moist; moderate coarse subangular blocky structure; slightly hard, friable, sticky and plastic; common very fine and fine roots; many very fine and fine tubular pores; moderately acid (pH 5.8); abrupt wavy boundary. (5 to 9 inches thick)
B2t--21 to 38 inches; brownish yellow (10YR 6/6) and very pale brown (10YR 7/3) clay loam, brown (10YR 5/3) and strong brown (7.5YR 5/6) moist; medium coarse subangular blocky structure; hard, friable, sticky and plastic; few very fine roots; many very fine interstitial and tubular and common fine tubular pores; common thin and few moderately thick clay films line pores, common thin clay films on faces of peds; faces of peds are very pale brown (10YR 7/3); few krotovinas are filled with soil from above; black (10YR 2/1) manganese stains, films and thin concretions; slightly acid (pH 6.3); diffuse wavy boundary. (12 to 24 inches thick)
B3t--38 to 51 inches; variegated light yellowish brown (10YR 6/4) and very pale brown (10YR 7/3) clay loam, variegated brown (10YR 5/3) and yellowish brown (10YR 5/6) moist; weak coarse subangular blocky structure; hard, friable, sticky and plastic; few very fine roots; common very fine interstitial and many very fine and fine tubular pores; few thin clay films line pores; less than 5 percent cobbles and about 5 percent pebbles by volume; black (10YR 2/1) manganese stains, films and thin concretions; moderately acid (pH 5.6); diffuse wavy boundary. (10 to 20 inches thick)
C--51 to 65 inches; reddish yellow (7.5YR 6/6) clay loam, variegated yellowish brown (10YR 5/6) and pale brown (10YR 6/3) moist; massive; hard, friable, sticky and plastic; few very fine roots; many very fine and fine tubular and many very fine interstitial pores; black (10YR 2/1) manganese stains;, films and thin concretions; strongly acid (pH 5.4).
TYPE LOCATION: Santa Cruz County, California; about 350 feet southerly and 57 feet easterly from the intersection of Webb and Casserly Roads, SE1/4 NE1/4 section 22, T.11S., R.2E. (projected)
RANGE IN CHARACTERISTICS: The soil between depths of 7 and 21 inches becomes moist in some part in October or November and remains moist until May. The mean annual soil temperature is about 59 to 61 degrees F. The solum is medium acid to neutral. Rock fragments make up 0 to 15 percent of the soil. Base saturation is more than 75 percent throughout the upper 30 inches of the B2t horizon.
The A1 horizon is grayish brown, brown or dark grayish brown (10YR 5/2, 5/3, 4/2, 4/3). It is very fine sandy loam, loam or light clay loam.
The A2 horizon is light brownish gray, pale brown, light gray or very pale brown (10YR 6/2, 6/3, 7/2, 7/3). It is fine sandy loam, loam or light clay loam. Color of the A2 horizon comes from coatings of the mineral grains.
The B2t horizon is brown, yellowish brown, light yellowish brown, brownish yellow, or very pale brown (10YR 5/3, 5/4, 6/4, 6/6, 7/3) or light brown or reddish yellow (7.5YR 6/4, 6/6). Coatings on faces of peds are white, light gray or light brownish gray silt in hue of 10YR or 2.5Y. Concretions and stains are black or very dark gray. This horizon is loam, sandy clay loam, clay loam, or loam and has about 25 to 35 percent clay.
The C horizon is reddish yellow, brown, light yellowish brown or very pale brown (7.5YR 7/6, 6/6, 5/4; 10YR 6/4, 7/3) with prominent very dark gray or black (10YR 2/1, 3/1) stains. It is sandy clay loam or clay loam. This horizon is moderately acid or strongly acid. In some pedons below a depth of 40 inches, the substratum is weakly silica cemented.
COMPETING SERIES: These are the Ballard, Chualar, Gilroy and Soper series. Ballard and Chualar soils lack an abrupt boundary between the A horizon and the B2t horizon. Gilroy and Soper soils have bedrock at depths of 20 to 40 inches.
GEOGRAPHIC SETTING: Pinto soils are on marine terraces and old alluvial fans and have slopes of 0 to 15 percent. They formed in alluvial material mainly from sedimentary rocks. Elevation is 20 to 1,000 feet. The soils are in a subhumid mesothermal climate with warm, dry summers and cool, moist winters. The mean annual precipitation is 20 to 30 inches. The average January temperature is 48 degrees F.; the average July temperature is 61 degrees F; and the average annual temperature is 57 to 59 degrees F. The frost free season is about 250 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Baywood, Elder, Elkhorn, Santa Ynez, Tierra and Watsonville soils. Baywood soils are sandy throughout. Elder soils have an irregular decrease in organic matter with depth and lack B2t horizons. Elkhorn soils lack abrupt A/B horizon boundaries and have more than 1 percent organic matter to depths of more than 20 inches. Santa Ynez, Tierra and Watsonville soils have B2t horizons with more than 35 percent clay.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow to rapid runoff; slow permeability.
USE AND VEGETATION: Used mainly for row crops, hay, pasture and some apple orchards. Vegetation is mainly coastal chaparral, grasses and forbs.
DISTRIBUTION AND EXTENT: Coastal and valley terraces along the central California coast and valleys. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Santa Cruz County, California, 1928.
REMARKS: The A2 horizon is not considered to be an albic horizon.
The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET