LOCATION BORREGUERO CAEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, thermic, shallow Typic Haploxerepts
TYPICAL PEDON: Borreguero sandy loam - on a north facing slope of 45 percent under soft chess, rattail fescue, pine bluegrass, California sagebrush, California buckwheat, California ephedra, goldenbush and California juniper. The elevation is 1,940 feet. (Colors are for dry soil unless otherwise stated. When described May 21, 1984 the soil was dry throughout).
A--0 to 2 inches: brown (10YR 5/3) and light yellowish brown (10YR 6/4) sandy loam, dark brown (10YR 3/3) and dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common medium, many very fine and fine roots; common medium, very fine tubular and many very fine interstitial pores; 18 percent clay content; slightly acid (pH 6.5); abrupt smooth boundary. (1 to 5 inches thick)
Bw1--2 to 5 inches; brown (10YR 5/3) sandy clay loam, brown (10YR 4/3) moist; weak medium and coarse subangular blocky structure; very hard, friable, slightly sticky and slightly plastic; few medium and common very fine roots; common very fine tubular and interstitial pores; 20 percent clay content; neutral (pH 7.0); abrupt smooth boundary. (2 to 6 inches thick)
Bw2--5 to 11 inches; yellowish brown (10YR 5/4) and brownish yellow (10YR 6/6) sandy clay loam, dark yellowish brown (10YR 4/4) and yellowish brown (10YR 5/6) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common medium, many very fine and fine roots; common medium, fine and very fine tubular and many very fine and fine interstitial pores; 21 percent clay content; 10 percent pieces of weathered sandstone; neutral (pH 7.0); clear smooth boundary. (5 to 12 inches thick)
Cr--11 to 17 inches; slightly weathered, soft sandstone; 0.5 inch cracks, 6 inches apart.
TYPE LOCATION: Fresno County, California; approximately 900 feet west of Borreguero Springs, 5.75 miles west northwest of Lillis Ranch; approximately 2,630 feet west and 400 feet south of the northeast corner of section 29, T.17 S., R.13 E., MDB&M; Latitude 36 degrees, 25 minutes, 39 seconds north and Longitude 120 degrees, 34 minutes, 47 seconds west; USGS Ciervo Mountain Topographic Quadrangle, NAD 27.
RANGE IN CHARACTERISTICS: Depth to a paralithic contact of marine sandstone is 10 to 20 inches. The moisture control section of 7 to 20 inches is moist from January 1 to May 1 and dry from June 1 to October 15 in most years. The soil temperature is above 47 degrees F. from February 15 to December 15. The mean annual soil temperature is 59 to 64 degrees F.
The A horizon has color of 10YR 5/3, 5/4 or 6/4. Moist color is 10YR 3/3, 3/4 or 4/4. Organic matter content is 1 to 2 percent. Clay content is 12 to 20 percent. Reaction is slightly acid or neutral.
The Bw1 horizon has color of 10YR 5/2, 5/3 or 5/4. Moist color is 10YR 4/2 or 4/3. Texture is sandy loam, loam or sandy clay loam. Organic matter content is 1 to 2 percent. Clay content is 14 to 25 percent. Reaction is slightly acid or neutral.
The Bw2 horizon has color of 10YR 5/4, 6/4 or 6/6. Moist color is 10YR 4/4 or 5/6. Organic matter is 0.1 to 0.8 percent. Texture is sandy loam or sandy clay loam. Clay content is 14 to 23 percent.
COMPETING SERIES: These are the Amador, Osito and Wolfey series. Amador soils (MLRA 18) are on hills, formed from rhyolitic tuffaceous sediments, are influenced by ash, and have a mean annual soil temperature of 64 to 67 degrees F. Osito soils (MLRA 20) are on uplands, weathered from interbedded andstone and shale, have silt loam textures and have a mean annual soil temperature of 59 to 70 degrees F. Wolfey soils (MLRA 5) are on hills and mountains with mean annual precipitation of 45 to 60 inches and have reaction of moderately acid or slightly acid in the Bw horizon.
GEOGRAPHIC SETTING: Borreguero soils are on mountain slopes and escarpments on mountains. Slope is 30 to 65 percent. Elevation is 679 to 4810 feet. These soils formed in material weathered from marine sandstone. The climate is semiarid with hot dry summers and cool moist winters. The mean annual precipitation is 9 to 20 inches. Mean January temperature is 46 degrees F; mean July temperature is 81 degrees F; mean annual temperature is 57 to 63 degrees F. The frost-free season is 170 to 240 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Exclose, Gewter, and Grazer soils. Exclose soils are on mountains and have a fine-loamy particle-size control section and are deeper than 60 inches. Gewter soils are on hills and are deeper than 20 inches and are very strongly acid. Grazer soils are on mountains and have a fine particle-size control section, and are deeper than 40 inches.
DRAINAGE AND PERMEABILITY: Well drained; very high runoff; moderately slow permeability (compacted B horizon).
USE AND VEGETATION: These soils are used for livestock grazing and wildlife habitat. The vegetation is soft chess, rattail fescue, red brome, pine bluegrass, California sagebrush and California buckwheat.
DISTRIBUTION AND EXTENT: These soils are in the Diablo Range in the California Coast Ranges. They are moderately extensive. MLRA 15.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Fresno County, California, 2002. Named after nearby Borreguero Springs.
REMARKS: These soils were formerly mapped as Rough Broken Land in the unpublished report, Soil Survey of Western Fresno, 1967. They are being differentiated by being classified and mapped. The pH is determined by colorimetric method using Thymol Blue and Hellige-Truog Triplex indicators. Texture determined by hydrometer method. In 1997 the classification of the tentative soil series was changed from loamy, mixed, nonacid, thermic, shallow Typic Xerorthents to the current classification.