LOCATION DELDOTA CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Vertic Haploxerolls
TYPICAL PEDON: Deldota clay-on a slope of 1 percent in a harvested oat and barley field at an elevation of 174 feet. (Colors are for dry soil unless otherwise stated. When described on May 10, 1979, the soil was moist below 4 inches and saturated below 54 inches).
Ap1--0 to 4 inches; grayish brown (10YR 5/2) and brown (10YR 5/3) clay, very dark grayish brown (2.5Y 3/2) moist; strong very coarse prismatic and moderate medium subangular blocky structure; very hard, firm, moderately sticky and very plastic; common very fine roots; few very fine and fine tubular pores; 1 percent gravel 5 to 25 mm in size; many thick pressure faces, 42 percent clay content; slightly alkaline (pH 7.5); abrupt smooth boundary.
Ap2--4 to 9 inches; grayish brown (2.5Y 5/2) clay, very dark grayish brown (2.5Y 3/2) moist; strong very coarse prismatic and moderate medium subangular blocky structure; very hard, firm, moderately sticky and very plastic; common very fine roots; few very fine and fine tubular pores; many pressure faces; 2.3 percent organic matter; 42 percent clay content; electrical conductivity is 0.58 decisiemens per meter; sodium adsorption ratio is 5.0; slightly alkaline (pH 7.5); abrupt smooth boundary.
A--9 to 17 inches; grayish brown (2.5Y 5/2) clay, very dark grayish brown (2.5Y 3/2) moist, high and low chroma mottles related to decomposing vegetation; strong very coarse medium prismatic structure; very hard, firm, moderately sticky and very plastic; common very fine roots; few very fine tubular pores; many pressure faces; 42 percent clay content; moderately alkaline (pH 8.0); clear wavy boundary. (Combined thickness of the A and Ap horizons is 10 to 19 inches).
Bw--17 to 24 inches; yellowish brown (10YR 5/4) clay loam, brown (10YR 4/3) moist; weak very coarse and moderate medium prismatic structure; hard, friable, very sticky and very plastic; few very fine roots; common very fine tubular pores; many pressure faces; 37 percent clay content; 9.5 percent calcium carbonate equivalent; slightly effervescent, carbonates disseminated; moderately alkaline (pH 8.0); clear wavy boundary. (5 to 8 inches thick)
Bk1--24 to 30 inches; light yellowish brown (2.5Y 6/4) clay loam, olive brown (2.5Y 4/4) moist; moderate medium subangular blocky structure; hard, friable, very sticky and very plastic; few very fine roots; common very fine tubular pores; common pressure faces; 36 percent clay content; 11 percent calcium carbonate equivalent; violently effervescent, carbonates disseminated and segregated as common fine irregularly shaped soft masses; moderately alkaline (pH 8.0); clear wavy boundary
Bk2--30 to 39 inches; light yellowish brown (2.5Y 6/4) clay loam, olive brown (2.5Y 4/4) moist; weak medium subangular blocky structure; hard, friable, moderately sticky and very plastic; few very fine roots; common very fine tubular pores; common pressure faces; 39 percent clay content; 11 percent calcium carbonate equivalent; violently effervescent, carbonates disseminated and segregated as few fine irregularly shaped soft masses and seams; electrical conductivity is 0.61 decisiemens per meter; sodium adsorption ratio is 5; moderately alkaline (pH 8,0); diffuse wavy boundary. (Combined thickness of the Bk is 14 to 30 inches)
C--39 to 68 inches; yellowish brown (10YR 5/4) clay loam, dark yellowish brown (10YR 4/4) moist; weak coarse subangular blocky structure; hard, friable, very sticky and moderately plastic; few very fine roots; common very fine tubular pores; common pressure faces; 38 percent clay content; 11 percent calcium carbonate equivalent; strongly effervescent, carbonates disseminated; redox depletions along root channels and few fine prominent greenish gray (5GY 6/1) moist iron depletions on faces of peds; moderately alkaline (pH 8.0)
TYPE LOCATION: Merced County, California; about 11 miles southeast of Los Banos, 3.5 miles west of Eagle Field Airport, 200 feet north of the Eastwest Drain, 400 feet west of the Northsouth Drain and 0.54 mile north of Eagle Field Road; 2,100 feet east and 1,500 feet north of the southwest corner of section 11, T. 12 S., R. 11 E., MDB&M; Latitude 36 degrees, 53 minutes, 56 seconds north and Longitude 120 degrees, 44 minutes, 16 seconds west; USGS Dos Palos Topographic Quadrangle, NAD 27.
RANGE IN CHARACTERISTICS: The soil between the depth of 4 and 12 inches is moist throughout from about January 15 to June 1 and dry throughout from July 15 to November 15. The soil temperature is warmer than 47 degrees F from January 15 to December 1. The mean annual soil temperature is 62 degrees to 66 degrees F. The soil, when dry and not cropped or irrigated, has cracks 1 to 2 inches wide at the surface and 1 to 2 cm wide at a depth of 20 inches from July 15 to November 15. The cracks are 10 to 20 inches apart but there are no wedge shaped structural aggregates or slickensides. Electrical conductivity is 0 to 2 decisiemens per meter. Gravel content is 0 to 3 percent.
The A horizon has color of 10YR 4/2, 5/2, 5/3; 2.5Y 5/2. Moist color is 10YR 3/2, 3/3 or 2.5Y 3/2. Organic matter content is 1 to 3 percent. Clay content is 40 to 50 percent. Calcium carbonate equivalent is 0 to 5 percent. Sodium adsorption ratio is 0 to 7. Reaction is slightly alkaline or moderately alkaline.
The Bw horizon has color of 10YR 5/4 or 5/6. Moist color is 10YR 3/3, 4/3, 4/4, 5/4 or 2.5Y 4/4. Texture is clay loam or clay. Clay content is 35 to 50 percent. Calcium carbonate equivalent is 0 to 15 percent. Sodium adsorption ratio is 2 to 12. Reaction is slightly alkaline or moderately alkaline.
The Bk horizon has color of 10YR 4/3, 4/4, 5/4, 6/4; 2.5Y 4/4 or 6/4. Moist colors are 10YR 3/3, 4/3, 4/4, 5/4 or 2.5Y 4/4. Texture is clay loam or clay. Clay content is 30 to 50 percent. Calcium carbonate equivalent of the Bk horizon is 5 to 20 percent but is less than 5 percent more than the C horizon. Sodium adsorption ratio is 2 to 12. Reaction is slightly alkaline or moderately alkaline.
The C horizon has color of 10YR 5/4, 5/6, 6/4 or 2.5Y 5/6. Moist color is 10YR 4/2, 4/3, 4/4, 4/6, 5/4 or 2.5Y 4/4. Clay content is 35 to 40 percent. Calcium carbonate equivalent is 1 to 20 percent. Sodium adsorption ratio is 2 to 7. Some pedons have manganese stains or few fine prominent 5Y 5/2 iron depletions on faces of peds and 5GY 6/1 iron depletions in root channels. Reaction is slightly alkaline or moderately alkaline.
COMPETING SERIES: These are the Zaca (CA) and Carbona (CA) series. Zaca soils (MLRA 15, 20), on hills and mountains, have a paralithic contact at a depth of 40 to 65 inches. Carbona soils (MLRA 17), on terraces, are well drained, and do not have a cambic horizon.
GEOGRAPHIC SETTING: Deldota soils are on fan skirts and low alluvial fans adjacent to the valley basin rim. Slope is 0 to 2 percent. These soils formed in mixed alluvium dominantly from sedimentary sources. They are on level or nearly level topography. Elevation is 90 to 300 feet. The climate is semiarid with hot dry summer and cool moist winters. The mean annual precipitation is 8 to 12 inches. Mean January temperature is 46 degrees F; mean July temperature is 79 degrees F and mean annual temperature is 60 to 64 degrees F. The frost-free season is 210 to 280 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dosamigos, Pedcat, and Woo soils. Dosamigos soils, on low alluvial fans adjacent to the valley basin rim, do not have wide cracks when dry. Pedcat soils, on low alluvial fans and fan remnants, have a natric horizon. Woo soils, on alluvial fans, have a fine-loamy particle-size control section and are well drained.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained and are now partially drained; negligible to medium runoff; slow permeability. Water table is at a depth of 18 to 60 inches from December through March.
USE AND VEGETATION: These soils are leveled and used for irrigated cropland producing truck, field, orchard, and hay crops.
DISTRIBUTION AND EXTENT: These soils occur on the west side of the San Joaquin Valley. They are moderately extensive. MLRA 17.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Merced County, California 1984
REMARKS: These soils were formerly included with and mapped as Lost Hills and Mocho series as mapped in the Los Banos Area, California, 1939 Series Report.
Diagnostic horizon and features recognized in this pedon are:
1. Mollic Epipedon -- The zone from 0 to 17 inches (Ap1, Ap2, A horizons)
1.1 Dry values are 5 or less, moist values are 3 or less and moist chromas are 3 or less. Organic matter determined by Walkley-Black method is 1 to 3 percent
2. Cambic Horizon -- The zone from 17 to 24 inches (Bw horizon)
2.1 Increase color chroma to 3, 4 or 6.
2.2 Lost of carbonates, calcium carbonate equivalent is 9.5 percent compared to 11 percent in the Bk horizon below.
2.3 Structure
3. Vertic subgroup: Surface cracks are 3 cm wide tapering to 1 cm at a depth of 20 inches. No slickensides or sphenoids.