LOCATION DOSAMIGOS CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Aquic Haploxerolls
TYPICAL PEDON: Dosamigos clay loam - on a smooth slope of 1 percent in an alfalfa field at 105 feet elevation. (Colors are for dry soil unless otherwise stated. When described on June 26, 1980, the soil was moist throughout ad saturated below 55 inches).
Ap1--0 to 5 inches; brown (10YR 5/3) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium and coarse subangular blocky structure; very hard, friable, sticky and very plastic; common very fine and few fine roots; common very fine tubular pores; exchangeable sodium percent is 5: electrical conductivity is 1 decisiemens per meter; moderately alkaline (pH 8.0); clear smooth boundary.
Ap2--5 to 14 inches; brown (10YR 5/3) clay, very dark grayish brown (10YR 3/2) moist; moderate medium and coarse subangular blocky structure; very hard, friable, very sticky and very plastic; common very fine roots; common very fine and few fine tubular pores; slightly effervescent with disseminated carbonates; 1.2 percent organic matter; exchangeable sodium percent is 9; electrical conductivity is 1 decisiemens per meter; moderately alkaline (pH 8.0); clear wavy boundary. (Combined thickness of the A is 11 to 19 inches)
Bn1--14 to 20 inches; brown (10YR 5/3) clay, brown (10YR 4/3) moist; few fine prominent black (N 2/0), dark brown (7.5YR 3/2), and dark gray (N 4/0) manganeses concretions moist; strong medium subangular blocky structure; very hard, firm, sticky and very plastic; common very fine roots; common very fine and few fine tubular pores; few moderately thick pressure faces; slightly effervescent with disseminated carbonates; exchangeable sodium percent is 16; electrical conductivity is 2 decisiemens per meter; moderately alkaline (pH 8.2); clear smooth boundary. (4 to 8 inches thick)
Bn2--20 to 29 inches; light yellowish brown (10YR 6/4) and yellowish brown (10YR 5/4) clay, yellowish brown (10YR 5/4) and brown (10YR 4/3) moist; strong medium subangular blocky structure; very hard, firm, very sticky and very plastic; few very fine roots; common very fine and few fine tubular pores; common thick pressure faces; slightly effervescent with disseminated carbonates; exchangeable sodium percent is 30; electrical conductivity is 3 decisiemens per meter; moderately alkaline (pH 8.2); clear smooth boundary. (Combined thickness of the Bn is 11 to 19 inches)
Bkn1--29 to 46 inches; light yellowish brown (10YR 6/4) clay loam, brown (10YR 5/3) moist; moderate medium subangular blocky structure; very hard, firm, sticky and very plastic; few very fine roots; many very fine and few fine tubular pores; common moderately thick clay films on peds and in pores; strongly effervescent with disseminated carbonates and segregated as few fine irregular soft masses; exchangeable sodium percent is 25; electrical conductivity is 3 decisiemens per meter; moderately alkaline (pH 8.2); clear smooth boundary. (16 to 20 inches thick)
Bkn2--46 to 52 inches; yellow (10YR 7/6) clay loam, brownish yellow (10YR 6/6) moist; few fine prominent dark brown (7.5YR 4/4) masses of iron accumulations moist; massive; very hard, friable, sticky and plastic; few very fine roots; few very fine and fine tubular pores; strongly effervescent with disseminated carbonates and segregated as few fine irregular soft masses; exchangeable sodium percent is 24; electrical conductivity is 3 decisiemens per meter; moderately alkaline (pH 8.2); abrupt wavy boundary. (5 to 8 inches thick)
2Ck--52 to 62 inches; brownish yellow (10YR 6/6) clay, yellowish brown (10YR 5/4) moist; moderate coarse prismatic structure; very hard, firm, very sticky and very plastic; no roots; few very fine tubular pores; few thin clay films o peds and line pores; strongly effervescent with disseminated carbonates and segregated as few fine irregular soft masses; very soft, very strongly weathered shale fragments; moderately alkaline (pH 8.2).
TYPE LOCATION: Merced County, California; 4.5 miles south of the city of Gustine; about 2,650 feet east of the C.C.I.D. Main Canal; 180 feet southwest of the intersection of Cottonwood and Hunt Roads, 130 feet south of the NE corner of sec. 5, T. 9 S., R. 9 E.
RANGE IN CHARACTERISTICS: The moisture control section is moist throughout from about January 15 to June 1 and dry throughout from about July 15 to November 15. The soil temperature is warmer than 47 degrees F from January 20 to December 1. The mean annual soil temperature is 60 to 64 degrees F. The water table is at a depth of 42 to 60 inches of the surface in December through March.
The A horizon is 10YR 4/2, 5/2, 5/3, 5/4; 2.5Y 5/2, or 5/4. Moist colors are 10YR 3/2, 3/3; 2.5Y 2/2, or 3/2. It is clay loam or clay. The clay content of the A horizon ranges from 35 to 45 percent. exchangeable sodium percent ranges from 5 to 10 and electrical conductivity is O to 2 decisiemens per meter.
The Bn horizon is 10YR 5/3, 5/4, 5/6, 6/2, 6/3, 6/4, 6/6, 7/4, 7/6; 2.5Y 6/2, or 6/4. Moist colors are 10YR 3/4, 4/1, 4/3, 4/4, 4/6, 5/4, 5/6, 6/6; or 2.5Y 4/4. Redoxomorphic features are few fine prominent 7.5YR 3/2, 3/4, 4/2; 10YR 3/1, 5/6; 2.5Y 2/1, 4/2; 5Y 4/1, 5/1; 5GY 4/1; N 2/0, or N 4/0 moist. Redoxomorphic features occur within 30 inches of the surface. Texture is clay or clay loam. Clay content ranges from 37 to 50 percent. The clay increase in the B horizon is less than 1.2 times that of the surface, and always less than 8 percent (absolute). exchangeable sodium percent ranges from 10 to 30 and electrical conductivity ranges from 0 to 2 decisiemens per meter.
The Bk horizon is 10YR 5/3, 5/4, 5/6, 6/3, 6/4, 6/6, 7/3, 7/6, 8/2, 8/6; 2.5Y 6/4, 7/6, or 8/4. Moist colors are 10YR 4/2, 4/3, *4/4,* 4/6, 5/3, 5/4, 5/6, 6/4, 6/6, 7/2, 7/6; 2.5Y 5/4, 6/6, or 7/4. Redoxomorphic features are few fine prominent 7.5YR 3/2, 3/4, 4/4, 5/6; 10YR 2/1, 4/2, 5/6; 2.5Y 3/2, 5/4, 7/6; 5Y 3/2, 4/1, 5/1, 5/3, 6/1, 6/3; 5GY 4/1; or N 2/0 moist. Texture is clay loam, clay, or sandy clay. Clay content ranges from 30 to 45 percent. The lower part of this horizon ranges from noncalcareous to strongly effervescent. Some pedons do not have strongly weathered shale fragments. Some pedons contain up to 10 percent brittle durinodes. exchangeable sodium percent ranges from 10 to 30 and electrical conductivity ranges from 2 to 16 decisiemens per meter.
COMPETING SERIES: These are Landlow (CA) soils in the same family and the Chateau, and Deldota series. Chateau soils have an ochric epipedon and more than 15 exchangeable sodium percent in the A horizon. Deldota soils have wide cracks to a depth of 20 inches when dry. Landlow soils have a weakly to strongly compacted Ck horizon and have an exchangeable sodium percent less than 5 throughout.
GEOGRAPHIC SETTING: Dosamigos soils are on low alluvial fans adjacent to the valley basin rim. Slopes are 0 to 2 percent. They formed in alluvium derived mostly from sedimentary rock. Most of this soil has been leveled but was hummocky in its natural microrelief. Elevations are 70 to 180 feet. The climate is semiarid with hot dry summers and cool moist winters. The mean annual precipitation is about 9 to 12 inches. Mean January temperature is 46 degrees F; mean July temperature is 79 degrees F. The mean temperature is about 60 to 62 degrees F. The frost-free season is about 210 to 280 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Chateau and Deldota soils and the Pescadero, Pedcat, and Stanislaus soils. Pescadero and Pedcat soils have a natric horizon and are poorly drained. Stanislaus soils lack mottles above 30 inches and are well drained.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained and now artificially drained; negligible to high runoff; very slow permeability. The water table is at a depth of 42 to 60 inches in December through March.
USE AND VEGETATION: This soil is in irrigated cropland and is used for field crops, alfalfa, and pastureland.
DISTRIBUTION AND EXTENT: These soils occur in low alluvial fans of the central San Joaquin Valley adjacent to the Coast Range foothills. They are not extensive.
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 Lethent and Orestimba series in the Los Banos Area, series 1939 report. These soils are being differentiated by a very slow permeability and a clayey control section. pH determined by colorimetric method using Thymol Blue and Hellige-Truog Triplex indicators. Texture determined by hydrometer method. Soluble salts and exchangeable sodium determined by saturation and extract. Organic matter determined by Walkley-Black digestion method. Presence of carbonates determined by 10 percent HC1 solution.
Runoff terminology updated 4/96 from slow to new criteria, and comply with the Soil Survey Manual, 10/93.
Last revised by the state on 7/96.
ADDITIONAL DATA: NSSL pedon S91CA-099-008 (partial pedon)