LOCATION DRYVALLEY CA

Established Series
Rev. SJB-JJJ-JVC
01/2023

DRYVALLEY SERIES

The Dryvalley series consist of very deep, well drained soils that formed in lacustrine deposits derived from volcanic rocks. Dryvalley soils are on lake terraces. Slopes are 0 to 2 percent. The mean annual precipitation is about 11 inches and the mean annual temperature is about 45 degrees F.

TAXONOMIC CLASS: Fine, smectitic, mesic Xerertic Haplargids

TYPICAL PEDON: Dryvalley silty clay loam--on a nearly level lake terrace under Wyoming big sagebrush and bottlebrush squirreltail at an elevation of 5,290 feet--rangeland. (Colors are for dry soil unless otherwise noted. When described on October 11, 1979, the soil was dry throughout.)

A1--0 to 2 inches; light brownish gray (10YR 6/2) silty clay loam, dark grayish brown (10YR 4/2) moist; moderate medium and thick platy structure; slightly hard, very friable, moderately sticky and moderately plastic; many very fine roots; many very fine tubular and interstitial pores; slightly alkaline (pH 7.5); abrupt smooth boundary.

A2--2 to 5 inches; light brownish gray (10YR 6/2) silty clay loam, dark grayish brown (10YR 4/2) moist; weak fine granular structure; soft, very friable, moderately sticky and moderately plastic; many very fine, common fine and few medium roots; many very fine tubular and common fine interstitial pores; slightly alkaline (pH 7.5); clear smooth boundary. (Combined thickness of the A horizons is 2 to 9 inches)

Bt1--5 to 10 inches; light brownish gray (10YR 6/2) silty clay, dark grayish brown (10YR 4/2) moist; strong medium and coarse angular blocky structure; hard, friable, very sticky and very plastic; common very fine and fine and few medium and coarse roots; common distinct clay films on faces of peds and lining pores; slightly alkaline (pH 7.5); clear smooth boundary.

Bt2--10 to 21 inches; pale brown (10YR 6/3) clay, brown (10YR 4/3) moist; moderate medium prismatic structure parting to strong medium and coarse angular blocky; very hard, firm, very sticky and very plastic; common very fine and few fine and medium tubular pores; many distinct clay films on faces of peds and lining pores; slightly alkaline (pH 7.5); clear smooth boundary. (Combined thickness of the Bt horizons is 14 to 18 inches)

BCt1--21 to 34 inches; light yellowish brown (10YR 6/4) clay, dark yellowish brown (10YR 4/4) moist; weak medium prismatic structure parting to moderate medium and coarse angular blocky; very hard, friable, very sticky and very plastic; few very fine, medium and coarse roots; few very fine and fine tubular pores; common distinct clay films on faces of peds and lining pores; moderately alkaline (pH 8.0); gradual wavy boundary.

BCt2--34 to 43 inches; light yellowish brown (10YR 6/4) silty clay loam, dark yellowish brown (10YR 4/4) moist; massive; hard, friable, moderately sticky and moderately plastic; few very fine, fine and medium roots; few very fine tubular pores; moderately alkaline (pH 8.0); gradual wavy boundary. (Combined thickness of the BCt horizons is 20 to 35 inches)

C--43 to 60 inches; light yellowish brown (2.5Y 6/4) silty clay loam, olive brown (2.5Y 4/4) moist; massive; hard, friable, moderately sticky and moderately plastic; few very fine, few fine, and few medium roots; few very fine tubular pores; moderately alkaline (pH 8.0).

TYPE LOCATION: Lassen County, California; about 3 miles west-northwest of Termo; found by going 0.5 miles southwest from Termo on the Grasshopper Road from U.S. Highway 395 on dirt road through a gravel pit; approximately 1,300 feet north and 2,100 feet west of the southeast corner of section 20, T. 35 N., R. 13 E.; USGS Anderson Mountain 7.5 minute topographic quadrangle; 40 degrees 52 minutes 44 seconds north latitude and 120 degrees 31 minutes 38 seconds west longitude, NAD27.

RANGE IN CHARACTERISTICS:

Soil moisture - The soil moisture control section is moist throughout from about December 1 to May 1, dry throughout from June 15 to November 15 (150 days); the soil temperature exceeds 41 degrees F from April 1 to December 1 (245 days); Aridic moisture regime that borders on xeric.

Mean annual soil temperature - 48 to 50 degrees F.

Depth to base of argillic horizon - 21 to 43 inches.

Particle-size control section - Clay content: 40 to 60 percent; Sand content: Less than 10 percent; Rock fragments: 0 to 1 percent.

Linear extensibility (LE) - 6 to 8 cm.

A horizons - Dry color: 10YR 6/2 or 6/3.
Moist color: 10YR 3/2 or 4/2.
Texture: Silt loam or silty clay loam.
Reaction: Neutral or slightly alkaline.

Bt horizons - Dry color: 10YR 6/2, 6/3, or 5/4.
Moist color: 10YR 3/3, 3/4, 4/2, 4/3, or 4/4.
Texture: Silty clay or clay.
Clay content: 40 to 60 percent.
Reaction: Slightly alkaline or moderately alkaline.

BCt horizons - Dry color: 10YR 6/4 or 2.5Y 6/2.
Moist color: 10YR 4/3, 4/4, 5/4 or 2.5YR 4/4.
Clay content: 30 to 60 percent.
Reaction: Slightly alkaline or moderately alkaline.

C horizon - Dry color: 2.5Y 6/2, 6/4, 7/4 or 5Y 8/2.
Moist color: 2.5Y 4/4 or 5Y 4/3.
Clay content: 30 to 40 percent.
Reaction: Slightly alkaline or moderately alkaline.
Other features: Some pedons have 2C horizons at a depth of 40 inches or more that are stratified sandy loam and sand and extend to depth of 65 to as much as 80 inches.

COMPETING SERIES: These are the Ninekar and Sorefoot series.

Ninekar soils are moderately deep to lithic contacts. Sorefoot soils have 10 to 30 percent rock fragments in the particle-size control section and have horizons with identifiable secondary carbonates.

GEOGRAPHIC SETTING: Dryvalley soils are on lake terraces. These soils formed in lacustrine deposits derived from volcanic rocks such as basalt, andesite, and tuff. Slopes are 0 to 2 percent. Elevations range from 5,290 to 5,350 feet. The climate is semiarid with cold, moist winters and warm, dry summers. The mean annual precipitation is 10 to 12 inches including 10 to 20 inches of snow. The mean January soil temperature is 36 to 39 degrees F. and the mean July soil temperature is 60 to 63 degrees F. The mean annual temperature is 44 to 46 degrees F., the mean January temperature is about 26 degrees F., and the mean July temperature is about 64 degrees F. The frost-free period is 60 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ravendale, Springmeyer, and Termo soils. Ravendale soils have vertical cracks from the soil surface to about 50 inches that open and close each year. Springmeyer soils are fine-loamy, have mollic epipedons, and argillic horizons. Termo soils are very-fine and have natric horizons.

DRAINAGE AND PERMEABILITY: Well drained; high surface runoff; slow permeability.

USE AND VEGETATION: Dryvalley soils are used for rangeland. The vegetation is Wyoming big sagebrush, bottlebrush squirreltail, and Thurber's needlegrass.

DISTRIBUTION AND EXTENT: Northeastern California. These soils are moderately extensive. MLRA 23.

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 5 inches (A1 and A2 horizons).

Argillic horizon - The zone from 5 to 21 inches (Bt1 and Bt2 horizons).

Particle-size control section - The zone from 5 to 21 inches (Bt1 and Bt2 horizons).

ADDITIONAL DATA: The typical pedon at the series type location has characterization data by the Soil Survey Laboratory (SSL), Lincoln, NE, as soil survey sample number S81CA-035-008 (pedon # 81P0700).

National Cooperative Soil Survey
U.S.A.