LOCATION BOBERT CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Durinodic Xeric Natrargids
TYPICAL PEDON: Bobert sandy loam--on 1 percent slope under a plant community of basin big sagebrush and black greasewood--rangeland. (When described April 7, 1986, the soil was moist to 26 inches. Colors are for dry soil unless otherwise noted).
A--0 to 6 inches; light brownish gray (10YR 6/2) sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium and thick platy structure; soft, very friable, slightly sticky and slightly plastic; few very fine and fine roots; many very fine interstitial pores; moderately alkaline (pH 7.9); clear wavy boundary. (6 to 10 inches thick).
Btnk--6 to 14 inches; pale brown (10YR 6/3) sandy clay loam, brown (10YR 4/3) moist; moderate fine and medium prismatic structure parting to strong fine and medium angular blocky; hard, very friable, moderately sticky and moderately plastic; common very fine, fine and few medium roots; common very fine tubular pores; many faint and distinct clay films on faces of peds, lining pores, and bridging mineral grains; strongly effervescent, secondary carbonates segregated in common fine and medium masses; moderately alkaline (pH 8.2); clear wavy boundary. (8 to 24 inches thick).
Bqk--14 to 26 inches; very pale brown (10YR 7/3) loam, dark yellowish brown (10YR 4/4) moist; moderate thin and medium platy structure; hard, brittle and firm, moderately sticky and moderately plastic; few very fine and fine roots; few very fine tubular pores; 70 percent of horizon fragments slake in water; common thin silica coats with a glassy luster; strongly effervescent; strongly alkaline (pH 8.6); clear wavy boundary. (6 to 12 inches thick).
Bk1--26 to 52 inches; very pale brown (10YR 7/3) sandy loam, dark yellowish brown (10YR 4/4) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; common very fine tubular pores; violently effervescent with carbonates disseminated in the matrix; strongly alkaline (pH 8.6).
Bk2--52 to 60 inches; light gray (2.5Y 7/2) sandy loam, dark yellowish brown (10YR 4/4) moist; slightly hard, very friable slightly sticky and slightly plastic; few very fine roots; common very fine tubular pores; violently effervescent with carbonates disseminated in the matrix; strongly alkaline (pH 8.6).
TYPE LOCATION: Lassen County, California; in Honey Lake Valley about 4 miles east of Litchfield; found by going along Hwy. 395 to Wendel road, 0.5 mile along Wendel road to trail, and south along trail 0.2 mile; approximately 100 feet west and 2,200 feet north of the southeast corner of section 17, T. 29 N., R. 15 E.; USGS Wendel Hot Springs 7.5 minute topographic quadrangle; 40 degrees 22 minutes 23.9 seconds north latitude and 120 degrees 18 minutes 15.8 seconds west longitude, NAD27.
RANGE IN CHARACTERISTICS:
Soil moisture - These soils are dry in all parts of the soil moisture control section (6 to 15 inches) from June 1 to November 15 (167 days) and moist in all parts from December 1 to April 15. The soil temperature exceeds 41 degrees F from March 1 to December 15 (290 days) and exceeds 47 degrees F from April 15 to November 15; Aridic moisture regime that borders on xeric.
Mean annual soil temperature - 53 to 56 degrees F.
Ochric epipedon thickness - 6 to 10 inches.
Depth to base of natric horizon - 14 to 28 inches.
Depth to horizon with firm consistence and a brittle manner of failure - 14 to 28 inches.
Particle-size control section - Clay content: Averages 25 to 30 percent; Sand content: 35 to 55 percent.
A horizon - Dry color: 10YR 6/2, 6/3, or 7/2.
Moist color: 10YR 3/2, 3/3, or 4/2.
Reaction: Slightly alkaline or moderately alkaline.
Effervescence: Noneffervescent through strongly effervescent.
Btnk horizon - Dry color: 10YR 5/4, 6/3, 6/4, 7/2 or 2.5Y 6/2.
Moist color: 10YR 3/4, 4/2, 4/3, 4/4 or 2.5Y 4/2.
Texture: Loam, sandy clay loam, or clay loam.
Clay content: 25 to 30 percent.
Reaction: Moderately alkaline or strongly alkaline.
Effervescence: Noneffervescent through strongly effervescent.
Identifiable secondary carbonates: Occurs as few to many, fine or medium masses.
Calcium carbonate equivalent: 1 to 4 percent.
Sodicity (SAR): 50 to 200.
Salinity (EC): 4 to 16 mmhos/cm.
Bqk horizon - Dry color: 10YR 7/3; 2.5Y 6/4, 7/2, or 8/2.
Moist color: 10YR 4/3, 4/4; 2.5Y 4/2, 4/4, 5/2, 5/4, 6/4, or 5Y 4/3.
Texture: Sandy loam or loam.
Reaction: Moderately alkaline or strongly alkaline.
Effervescence: Strongly effervescent or violently effervescent.
Identifiable secondary carbonates: When present, occurs as few or common masses. Calcium carbonate equivalent: 1 to 5 percent.
Sodicity (SAR): 50 to 100.
Salinity (EC): 8 to 16 mmhos/cm.
Bk horizon - Dry color: 10YR 6/3, 7/2, 7/3; 2.5Y 7/2 or 5Y 7/4.
Moist color: 10YR 3/4, 4/3, 4/4, 5/4; 2.5Y 4/2, 4/4, 5/2; 5Y 4/3, 5/3 or 6/4.
Texture: Loam or sandy loam.
Reaction: Moderately alkaline or strongly alkaline.
Effervescence: Slightly effervescent through violently effervescent.
Calcium carbonate equivalent: 1 to 5 percent.
Sodicity (SAR): 30 to 100.
Salinity (EC): 4 to 32 mmhos/cm.
COMPETING SERIES: These are the Geysen, Godecke, and Pokergap series.
Geysen soils have natric horizons with sodium adsorption ratios of 13 to 45 and have mean annual soil temperature of 48 to 52 degrees F. Godecke soils average 31 to 35 percent clay in the particle-size control section, have natric horizons with sodium adsorption ratios of 31 to 45, and have mean annual soil temperature of 48 to 53 degrees F. Pokergap soils average 10 to 25 percent gravel in the particle-size control section, have natric horizons with sodium adsorption ratios of 13 to 23, and have horizons within 14 inches of the soil surface that contain 35 to 60 percent gravel.
GEOGRAPHIC SETTING: Bobert soils are on lake terraces and stream terraces. These soils formed in alluvium derived from mixed rocks. Slopes are 0 to 2 percent. Elevation ranges from 4,000 to 4,120 feet. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 9 to 12 inches. The mean annual temperature is 50 to 52 degrees F. The frost-free period is 100 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Herjun, Honlak, Standish, and Yobe soils. Herjun soils are coarse-loamy and do not have natric horizons. Honlak soils have endosaturation within 40 inches of the soil surface. Standish soils are fine and do not have horizons with a firm, brittle matrix. Yobe soils are fine-silty and do not have natric horizons.
DRAINAGE AND PERMEABILITY: Moderately well drained or well drained; medium surface runoff; slow permeability. Endosaturation is present with an apparent seasonal high water table between 3.5 and 5 feet (deep free water occurrence class) between December and April. Cumulative annual duration class is Common.
USE AND VEGETATION: Bobert soils are used as rangeland with some areas used for irrigated pasture. In rangeland the vegetation is basin big sagebrush, spiny hopsage, black greasewood, and inland saltgrass.
DISTRIBUTION AND EXTENT: Northeastern California. These soils are moderately extensive. MLRA 23, 27.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Lassen County (Susanville Area Soil Survey), California, 2000.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 6 inches (A horizon).
Natric horizon - The zone from 6 to 14 inches (Btnk horizon).
Identifiable secondary carbonates - The zone from 6 to 14 inches (Btnk horizon).
Duric feature - The zone from 14 to 26 inches (Bqk horizon).
Particle-size control section - The zone from 6 to 14 inches (Btnk horizon).