LOCATION CHINVAR CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Aquic Haploxerolls
TYPICAL PEDON: Chinvar loam, on a smooth leveled field of less than 1 percent under fescue trefoil permanent pasture and at an elevation of 104 feet. (Colors are for dry soil unless otherwise stated. When described on November 16, 1979, the soil was slightly moist to 13 inches and moist below.)
Ap1--0 to 3 inches; brown (10YR 5/3) and yellowish brown (10YR 5/4) loam, dark brown (10YR 3/3 and 4/3) moist; strong medium granular structure; slightly hard, friable, slightly sticky and plastic; common very fine roots; common very fine and few fine tubular pores; 2.3 percent organic matter; moderately alkaline (pH 8.0); clear smooth boundary. (2 to 5 inches thick)
Ap2--3 to 8 inches; brown (10YR 5/3) and light yellowish brown (10YR 6/4) loam, dark brown (10YR 3/3) and dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and plastic; few very fine roots; common very fine and few fine tubular pores; 2.0 percent organic matter; EC is 2 mmhos/cm; ESP is 9; moderately alkaline (pH 8.0); abrupt wavy boundary. (4 to 7 inches thick)
A--8 to 13 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, friable, sticky and plastic; common very fine roots; few very fine tubular pores; 2.5 percent organic matter; moderately alkaline (pH 8.0); abrupt irregular boundary. (4 to 7 inches thick)
C1--13 to 20 inches; yellowish brown (10YR 5/4) loam, dark yellowish brown (10YR 4/4) moist; moderate fine platy and weak medium subangular blocky structure; very hard, friable, sticky and plastic; few very fine roots; few very fine tubular pores; 0.3 percent organic matter; slightly effervescent with disseminated lime; EC is 4 mmhos/cm; ESP is 11; moderately alkaline (pH 8.0); abrupt irregular boundary. (6 to 8 inches thick)
Ck--20 to 26 inches; yellowish brown (10YR 5/4) loam, dark yellowish brown (10YR 3/4) moist; few fine distinct brownish yellow (10YR 6/8) mottles; few fine prominent grayish brown (2.5Y 5/2) and light gray (2.5Y 7/2) mottles moist; weak medium subangular blocky structure; very hard, friable, sticky and plastic; few very fine roots; common very fine tubular pores; slightly effervescent with disseminated lime and segregated as few fine irregular filaments; EC is 4 mmhos/cm; ESP is 12; moderately alkaline (pH 8.0); clear smooth boundary. (5 to 9 inches thick)
C2--26 to 38 inches; light yellowish brown (10YR 6/4) loam, dark yellowish brown (10YR 4/4) moist; few fine prominent brown (7.5YR 5/4) mottles; few fine prominent dark brown (7.5YR 3/4) mottles moist; massive; hard, friable, sticky and plastic; few very fine roots; few very fine tubular pores; slightly effervescent with disseminated lime and segregated as few fine irregular filaments; EC is 4 mmhos/cm; ESP is 10; moderately alkaline (pH 8.0); clear smooth boundary. (11 to 14 inches thick)
2C1--38 to 49 inches; light yellowish brown (10YR 6/4) gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; no roots; many very fine interstitial pores; 20 percent gravel, 2 to 20 mm in size; moderately alkaline (pH 8.0); clear smooth boundary. (8 to 15 inches thick)
2C2--49 to 60 inches; light yellowish brown (10YR 6/4) very gravelly loam, dark yellowish brown (10YR 4/4) moist; massive; slightly hard, loose, nonsticky and nonplastic; many very fine itnerstitial pores; 50 percent gravel, 2 to 20 mm in size; EC is 2; ESP is 7; slightly alkaline (pH 7.6).
TYPE LOCATION: Merced County, California; about 12 miles northwest of the city of Los Banos, 1,800 feet north and 1,100 feet east of the SW corner of Section 23, T. 9 E., R. 9 E., Ingomar Quadrangle.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 59 degrees to 62 degrees F. The soil is warmer than 47 degrees F from January 20 to December 1. The soil between 8 and 24 inches is moist in all parts from January 1 to May 1 and dry in all parts from July 1 to November 1. The water table fluctuates between 36 and 60 inches of the surface during December through March. Exchangeable sodium percentage ranges from 5 to 14 and is generally higher in the underlying material than in the surface.
The A horizon is 10YR 4/2, 5/2, 5/3, 5/4 or 6/4. Moist colors are 10YR 3/1, 3/2, 3/3, 4/3 or 4/4. Color values higher than 5.5 dry or 3.5 moist and chromas higher than 3.5 moist are in mixed colors, but are of minor extent. Clay content ranges from 20 to 27 percent. Organic matter ranges from 1 to 3 percent. EC ranges from 1 to 2.
The C horizon is 7.5YR 6/4; 10YR 5/4, 6/4, 6/6, 7/3, 7/6; 2.5Y 4/4, 6/2, 7/4; 5Y 6/2 or 7/4. Moist colors are 7.5YR 4/4; 10YR 3/4, 4/4, 4/6, 5/3, 5/6; 2.5Y 4/2, 5/4; 5Y 4/1 or 5/3 when mottles are present. Mottles are few fine distinct 10YR 3/1, 3/2 or 5/8 moist or few fine prominent 7.5YR 3/4, 4/6; 2.5Y 5/2, 5/6, 7/2; N 2/0, N 3/0 or N 4/0 moist. It is loam, clay loam, gravelly sandy loam, or very gravelly loam with 10 to 30 percent clay content. It is noncalcareous to strongly effervescent with disseminated lime. EC ranges from 2 to 6 mmhos/cm. It is dlightly alkaline or moderately alkaline.
COMPETING SERIES: These are the Chino series in the same family and the Bolfar, Carranza and Woo series in other families. Chino soils have strongly effervescent A horizons and are poorly drained. Bolfar soils have A horizons thicker than 24 inches and have an aquic moisture regime. Carranza soils have a pachic epipedon and are well drained. Woo soils effervesce throughout and are well drained.
GEOGRAPHIC SETTING: Chinvar soils are on low alluvial fans and creek overflows and have slopes of 0 to 2 percent. Elevations range from 80 to 115 feet. These soils formed in mixed alluvium dominantly from sedimentary rock sources. The climate is semiarid with hot dry summers and cool moist winters. The mean annual precipitation is 9 to 12 inches. The mean January temperature is 46 degrees F.; mean July temperature is 79 degrees F.; and the mean annual temperature is 62 degrees F. The frost free season is 210 to 280 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Chino and Woo soils and the Dosamigos soils. Dosamigos soils are fine textured and are poorly drained.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained, slow runoff, moderate permeability. The water table fluctuates between 36 and 60 inches of the surface during December through March.
USE AND VEGETATION: These soils are used as pasture and as cropland. The pasture vegetation includes fescue and treefoil, the crops grown include alfalfa, oats and corn.
DISTRIBUTION AND EXTENT: These soils occur in low alluvial fans and as creek overflows in 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. The name is coined.
REMARKS: These soils were mapped as Sorrento fine sandy loam in the Los Banos Area, Series 1939 report. They are being differentiated by being somewhat poorly drained and having an aquic intergraded moisture regime. pH determined by colormetric method using Thymol Blue and Hellige-Troug Triplex indicators. Texture determined by hydrometer method. Soluble salts and exchangeable sodium determined by saturation extract. Organic carbon determined by Walkely-Black digestion method. Presence of lime determined by 10 percent HC1.
The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET