LOCATION HERITO CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Typic Palexeralfs
TYPICAL PEDON: Herito loam - on a slope of 2 percent under soft chess, filaree, clover, and other annual grasses and forbs at an elevation of 400 feet. (Colors are for dry soil unless otherwise stated. When described on July 5, l978, the soil was dry throughout.)
A1--0 to 3 inches; brown (7.5YR 5/4) loam, dark brown (7.5YR 3/4) moist; moderate coarse and very coarse subangular blocky structure; very hard, very friable, slightly sticky and slightly plastic; common very fine roots; common very fine and fine tubular pores; 22 percent clay contents; slightly acid (pH 6.5); clear smooth boundary.
A2--3 to 10 inches; brown (7.5YR 5/4) loam, dark brown (7.5YR 3/4) moist; weak medium and coarse subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine tubular pores; 24 percent clay contents; neutral (pH 7.0); abrupt smooth boundary. (combined thickness of the A horizon is 7 to 15 inches)
E--10 to 12 inches; light brown (7.5YR 6/4) loam, brown (7.5YR 4/4) moist; weak medium subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; common very fine roots, many very fine tubular pores; 23 percent clay content; neutral (pH 7.0); clear smooth boundary. (1 to 3 inches thick)
Bt1--12 to 16 inches; brown (7.5YR 4/4) clay loam, dark brown (7.5YR 3/4) moist; strong medium prismatic structure; very hard, friable, sticky and plastic; few very fine roots; few very fine tubular pores; common moderately thick clay films on peds and in pores; 36 percent clay contents; neutral pH 7.0); clear smooth boundary.
Bt2--16 to 28 inches; strong brown (7.5YR 4/6) clay loam, dark brown (7.5YR 3/4) moist; moderate medium prismatic structure; very hard, friable, sticky and plastic; few very fine roots; few very fine tubular pores; 36 percent clay content common moderately thick clay films on peds; neutral (pH 7.0); clear smooth boundary. (combined thickness of Bt1 and Bt2 horizons is 12 to 24 inches)
BC--28 to 43 inches; brown (7.5YR 5/4) clay loam, dark brown 7/5YR 4/4) moist; moderate medium subangular blocky structure; hard, friable, sticky and plastic; few very fine roots; few very fine tubular pores; 35 percent clay content; common moderately thick clay films on peds; strongly effervescent with disseminated lime and segregated as few fine soft masses; moderately alkaline; pH 8.0) gradual wavy boundary. (12 to 20 inches thick)
C--43 to 60 inches; strong brown (7.5YR 5/6) clay loam, dark brown (7.5YR 3/4) moist; weak coarse subangular blocky structure; hard, very friable, sticky and slightly plastic; few very fine roots; few very fine tubular pores; 32 percent clay content; common thin clay films on peds; moderately alkaline (pH 8.0).
TYPE LOCATION: Merced County, California; about 8 miles southwest of the city of Gustine, 1,100 feet south and 700 feet west of the NE corner of Section 8, T. 9 S., R. 8 E.
RANGE IN CHARACTERISTICS: The soil is more than 60 inches deep. Depth of the solum ranges from 35 to 60 inches. The mean annual soil temperature is 59 degrees to 64 degrees F. The soil temperature is below 47 degrees F in parts of January and February and is never below 41 degrees F at any time. The soil between the depths of 6 and 18 inches is moist throughout from January 1 to May 1 and dry throughout from July 1 to November 1. Clay content of the A and E horizons ranges from 18 to 25 percent. The B horizon has 35 to 40 percent clay content and chroma of 6 or more in some part. The C horizon has 30 to 35 percent clay content but never decreased by 20 percent or more from the maximum in the B horizon within 1.5 m of the surface. Gravel content ranges from 0 to 10 percent throughout.
The A and E horizon is 10YR 5/3, 5/4; 7.5YR 5/4 or 6/4. Moist colors are 10YR 3/4, 4/4; 7.5YR 3/4 or 4/4. It is slightly acid or neutral.
The B horizon is 10YR 4/6, 5/6; 7.5YR 4/4, 4/6, 5/4 or 5/6. Moist colors are 10YR 4/4; 7.5YR 3/4, 4/4, 4/6 or 5/6. It is clay loam or sandy clay. It is neutral to moderately alkaline. Some pedons do not have segregated lime in the BC horizon.
The C horizon is 7.5YR 5/6, 5/8, 6/6 or 6/8. Moist colors are 7.5YR 3/4, 4/4, 4/6, 5/4, 5/6 or 5/8. It is clay loam or sandy clay loam. It is mildly alkaline or moderately alkaline.
COMPETING SERIES: These are the Hillgate and San Ysidro series in the same family and the Bapos, Cometa, Corning, Dibble, Los Banos, Millsap, Orognen, Ryer, Stomar and Yokayo series in other families. Hillgate and San Ysidro soils have very slow permeability and an abrupt A/B boundary with an increase of 18 percent clay (absolute) or more. Bapos soils have a mollic intergrade epipedon, very slow permeability and an abrupt A/B boundary with an increase of 15 percent clay or more. Cometa, Corning, and Orognen soils have mixed clay mineralogy and an abrupt boundary with an increase of 15 percent clay or more. Dibble soils have a paralithic contact at a depth of 20 to 40 inches. Los Banos soils have mixed clay mineralogy and the clay content drops more than 20 percent from the maximum of the argillic horizon within 1.5 m. Millsap soils have a lithic contact at a depth of 20 to 40 inches. Ryer and Stomar soils have clay contact that drops more than 20 percent from the maximum of the argillic horizon within 1.5 m and they do not have chromas of 6 or more in the argillic horizon. Yokayo soils have mixed clay mineralogy and receive 32 to 44 inches of precipitation.
GEOGRAPHIC SETTING: Herito soils are on terraces and have slopes of 0 to 2 percent. They formed in mixed alluvium dominantly from sedimentary sources. Elevations range from 250 to 500 feet. The climate is semiarid with hot dry summers and cool moist winters. The mean annual precipitation is about 10 to 12 inches. The mean January temperature is 46 degrees F; mean July temperature is 78 degrees F; and mean annual temperature is 62 degrees F. The frost-free season is about 210 to 280 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Bapos and Los Banos soils and the Anela, Carranza, Chaqua, and Damluis soils. Anela soils have a mollic epipedon and a loamy-skeletal texture control section. Carranza and Chaqua soils have a fine-loamy texture control section and do not have an argillic horizon. Damluis soils have a mollic epipedon.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; slow permeability.
USE AND VEGETATION: These soils are used as rangeland and upland wildlife habitat. The vegetation is soft chess, filaree, clover, red brome, fescue, wild oats, and other annual grasses and forbs.
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.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Merced County, California 1984. Name is coined.
REMARKS: These soils were mapped as Pleasanton, Rincon, and the now inactive Herdlyn series. They are being differentiated from the Pleasanton series by not having a fine-loamy texture control section, and from the Rincon series by having chromas of 6 or more in the argillic horizon and having less than a 20 percent drop in clay content below the argillic horizon. Reaction determined by colorimetric method using Thymol Blue and Hellig-Truog Triplex indicators. Texture determined by modified Bouyoucos method. Presence of lime determined by 10 percent HC1 solution. Organic matter assumed to be less than 1 percent based on Walkley-Black digestion method tests on adjacent soils.