LOCATION SUSANVILLE CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Vertic Natrixerolls
TYPICAL PEDON: Susanville very fine sandy loam, on a 1 percent slope under basin wildrye, big sagebrush and greasewood at 4035 feet elevation. (When described, August 22, 1984, the soil was dry throughout. Colors are for dry soil unless otherwise noted).
A--0 to 2 inches; light brownish gray (10YR 6/2) very fine sandy loam, dark grayish brown (10YR 4/2) moist; moderate medium platy structure parting to moderate medium subangular blocky; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots; many very fine and fine vesicular pores; neutral (pH 7.0); abrupt smooth boundary. (2 to 16 inches thick)
E--2 to 3 inches; light gray (10YR 7/2) very fine sandy loam, grayish brown (10YR 5/2) moist; moderate medium platy structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine and common fine vesicular pores; neutral (pH 7.0); abrupt smooth boundary. (0 to 2 inches thick)
Btn1--3 to 11 inches; very dark gray (10YR 3/1) clay, very dark grayish brown (10YR 3/2) moist; strong medium prismatic structure parting to strong fine angular blocky; very hard, firm, sticky and plastic; common very fine and many medium roots between peds; many very fine tubular pores; continuous thin clay films on peds; SAR is 29; E.C. is 3 mmhos; moderately alkaline (pH 8.2); clear smooth boundary.
Btn2--11 to 16 inches; dark gray (10YR 4/1) clay, black (10YR 2/1) moist; moderate fine angular blocky structure; very hard, friable, sticky and plastic; many medium and few very fine roots; many very fine tubular pores; many fine pressure faces; common thin clay films on peds; SAR is 43; E.C. is 12 mmhos; moderately alkaline (pH 8.2); clear wavy boundary. (The combined thickness of the Btn horizon is 12 to 20 inches)
Ayb--16 to 28 inches; dark gray (10YR 4/1) clay, black (N 2/0) moist; moderate medium subangular blocky structure; slightly hard, friable, sticky and plastic; few very fine roots, many very fine tubular pores; common clean sand grains on peds; few fine irregular soft masses and filaments of gypsum; moderately alkaline (pH 8.2); clear wavy boundary. (0 to 14 inches thick)
Byb1--28 to 39 inches; dark gray (10YR 4/1) silty clay, black (N 2/0) moist; few fine distinct mottles, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots, many very fine tubular pores; few fine irregular soft masses and filaments of gypsum; moderately alkaline (pH 8.2); clear wavy boundary.
Byb2--39 to 43 inches; dark gray (10YR 4/1) silty clay loam, black (N 2/0) moist; few fine distinct mottles, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; many very fine tubular pores; moderately alkaline (pH 8.2); abrupt wavy boundary. (The combined thickness of the Byb horizon is 12 to 18 inches).
2C--43 to 54 inches; light gray (2.5Y 7/2) silt loam, dark grayish brown (2.5Y 4/2) and very dark gray (N 3/0) moist; few fine distinct mottles, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; common very fine tubular pores; slightly effervescent with disseminated lime; moderately alkaline (pH 8.2); abrupt wavy boundary. (0 to 20 inches thick)
Ab--54 to 62 inches; dark gray (10YR 4/1) and dark gray (N 4/0) silty clay, black (N 2/0) moist; moderate fine angular blocky structure; hard, friable, sticky and plastic; no roots; common very fine tubular pores; few bits of charcoal; moderately alkaline (pH 8.2).
TYPE LOCATION: Lassen County, California; about 1.5 mile N of Standish, Ca.; located 80 feet E of the fence line running N-S through the center of section 8; 200 feet S and 80 feet E of the center of section 8, T.29 N., R.14 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature varies from 53 to 56 degrees F. The thickness of the solum is 16 to 35 inches. The depth to carbonates is 26 to 44 inches. The soil moisture control section (6 to 18 inches) is dry throughout from June 1 to November 15 (168 days) and is moist throughout 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. The soil is saturated between the depths of 60 and 72 inches at some time from January through April.
The A horizon is 10YR 4/2, 5/2 or 6/2. Moist colors are 10YR 2/1, 2/2, 3/2 or 4/2. When mixed, the upper 7 inches of soil has a dry value less than 5.5 and moist value less than 3.5. Reaction is neutral through moderately alkaline. It is very fine sandy loam or silt loam. Organic carbon content ranges from 0.7 to 1.5 percent.
The Btn horizon is 10YR 3/1, 4/1, 5/1 or 2.5Y 5/1. Moist color is 10YR 2/1, 2/2 or 3/2. It is clay or silty clay with 40 to 60 percent clay and 3 to 20 percent total sand. SAR ranges from 13 to 50. E.C. ranges from 2 to 12 mmhos.
The Ayb, Ab, Byb and 2C horizons are 10YR 4/1; 2.5Y 5/2, 6/1, 6/2, 7/2; N 4/1 or 4/0. Moist color are N 2/0, 3/0; 2.5Y 3/1, 3/2, 4/2 or 4/3. It is loam, clay loam, silt loam, silty clay loam or silty clay. SAR ranges from 30 to 100. E.C. ranges from 12 to 20 mmhos.
COMPETING SERIES: There are no other series in this subgroup.
GEOGRAPHIC SETTING: Susanville soils are on stream terraces. Slopes are 0 to 2 percent. These soils formed in mixed alluvium. Elevation ranges from 4,000 to 4,050 feet. The climate is semiarid with warm, dry summers and cold moist winters. The mean annual precipitation varies from 6 to 12 inches including 10 to 20 inches of snow. The mean annual temperature is about 50 degrees F. The average frost-free season is 100 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Calpine, Highrock and Smocreek soils. Calpine soils are coarse-loamy. Highrock soils are fine-loamy and have ochric epipedons. Smocreek soils are fine-silty.
DRAINAGE AND PERMEABILITY: Moderately well drained; runoff is slow; slow permeability. The soil is saturated between the depths of 60 and 72 inches at some time from January through April. Flooding is none to rare.
USE AND VEGETATION: Susanville soils are used as rangeland. The vegetation is basin wildrye, basin big sagebrush and greasewood.
DISTRIBUTION AND EXTENT: Lassen County, California. The soils of this series are not extensive. MLRA 26, 27.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Lassen County, California, Susanville Area, Parts of Lassen and Plumas Counties Soil Survey Area, 1988.
REMARKS: This pedon sampled for full characterization on 8/84. S84 CA 035-07-1 through 9.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon-zone from the soil surface to a depth of 16 inches (A, E, Btn1, Btn2).
Natric horizon-zone from 3 to 16 inches (Btn1, Btn2).
Vertic properties- based on lab data from associated soils that are fine and montmorillonitic, this soil was placed in Vertic subgroup.
Series reclassified 6/96. Competing series not updated at that time.