LOCATION CASSIRO NV+CA

Established Series
Rev. WED-RLB-JVC-JBF
11/2016

CASSIRO SERIES

The Cassiro series consists of deep or very deep, well drained soils that formed in alluvium derived from mixed rocks or in colluvium derived from quartzite and conglomerate. Cassiro soils are on fan remnants, inset fans, and hills. Slopes are 2 to 50 percent. The mean annual precipitation is about 250 mm and the mean annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic Aridic Argixerolls

TYPICAL PEDON: Cassiro gravelly sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 3 cm; brown (10YR 4/3) very gravelly sandy loam, very dark grayish brown (10YR 3/2) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine interstitial pores; 40 percent gravel; slightly acid (pH 6.5); clear wavy boundary. (0 to 13 cm thick)

A2--3 to 13 cm; brown (10YR 5/3) gravelly sandy loam, dark brown (7.5YR 3/2) moist; massive; slightly hard, very friable, nonsticky and nonplastic; many very fine roots; many very fine interstitial pores; 20 percent gravel; moderately acid (pH 6.0); clear wavy boundary. (0 to 20 cm thick)

A3--13 to 25 cm; brown (10YR 5/3) gravelly sandy loam, dark brown (7.5YR 3/2) moist; massive; hard, friable, nonsticky and nonplastic; common very fine, fine, medium, and coarse roots; many very fine interstitial pores; 30 percent gravel; moderately acid (pH 6.0); clear wavy boundary. (5 to 20 cm thick)

Bt1--25 to 38 cm; brown (10YR 5/3) gravelly sandy loam, dark brown (7.5YR 3/2) moist; weak fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine, fine, medium, and coarse roots; few very fine tubular pores; few faint clay films bridging and coating sand grains and lining pores; 15 percent gravel; moderately acid (pH 6.0); abrupt wavy boundary. (8 to 20 cm thick)

Bt2--38 to 66 cm; brown (7.5YR 5/4) very gravelly sandy clay, dark reddish brown (5YR 3/4) moist; moderate fine and medium subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; common very fine, fine, medium, and coarse roots; few very fine and fine tubular pores; common distinct clay films on faces of peds and lining pores; 40 percent gravel; moderately acid (pH 6.0); clear wavy boundary. (20 to 70 cm thick)

Bt3--66 to 114 cm; brown (7.5YR 5/4) very gravelly sandy clay, dark reddish brown (5YR 3/4) moist; massive; very hard, firm, moderately sticky and moderately plastic; few very fine roots; few very fine and fine tubular pores; many distinct clay films coating and bridging sand grains and lining pores; 40 percent gravel and 10 percent cobbles; moderately acid (pH 6.0); abrupt wavy boundary. (38 to 64 cm thick)

2Cr--114 to 165 cm; interbedded tuff and silty tuffaceous rock.

TYPE LOCATION: Washoe County, Nevada; in Lemmon Valley about 5 miles northwest of Reno; approximately 1,320 feet east and 150 feet south of the northwest corner of section 8, T. 20 N., R. 19 E.; USGS Verdi 7.5 minute topographic quadrangle; latitude 39 degrees 37 minutes 16 seconds N and longitude119 degrees 52 minutes 42 seconds W; WGS84 Decimal Degrees 39.6211111 latitude, -119.8783333 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist from late fall through spring, dry from summer through mid-fall; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 8 to 11 degrees C.
Mollic epipedon thickness: 25 to 40 cm; includes the Bt1 horizon in some pedons.
Depth to paralithic contact: 100 to more than 150 cm. The paralithic materials below the contact are interbedded tuff and silty tuffaceous sediments.

Particle-size control section - Clay content: 35 to 50 percent.
Rock fragments: 40 to 60 percent, mainly gravel, including up to 10 percent cobbles and stones. Lithology of fragments is mixed igneous rocks.

A horizons
Hue: 7.5YR or 10YR.
Value: 3 through 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Structure: Massive, platy, or subangular blocky.
Reaction: Moderately acid through slightly alkaline.
Organic matter content: 1 to 3 percent.

Bt horizons
Hue: 7.5YR or 10YR.
Value: 4 or 5 dry, 3 or 4 moist.
Chroma: 2 through 4, dry or moist.
Texture: Very gravelly sandy clay, very gravelly clay, or very gravelly clay loam.
Reaction: Moderately acid through slightly alkaline.
Organic matter content: 0.5 to 2 percent.

COMPETING SERIES: These are the Adelmann, Cochran, Eglirim, Fivesprings, Nammoth, Pickup, and Ruclick series.

Adelmann soils have mean annual soil temperature of 11 to 12 degrees C. Cochran soils are only very deep and are moderately acid in reaction. Eglirim soils are dominated by stones in the particle-size control section. Fivesprings, Nammoth, Pickup, and Ruclick soils are moderately deep to lithic contacts.

GEOGRAPHIC SETTING: Cassiro soils are on fan remnants, inset fans, and hills. These soils formed in alluvium derived from mixed rocks or in colluvium derived from quartzite and conglomerate. Slopes are 2 to 50 percent. Elevations range from 1,370 to 2,285 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 200 to 300 mm, the mean annual temperature is 8 to 10 degrees C, and the frost-free period is 100 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Indian Creek and Northmore soils. Indian Creek soils are clayey and shallow to duripans. Northmore soils are fine textured.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium runoff; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Cassiro soils are used for rangeland, recreation, and urban development. The vegetation is principally horsebrush, Anderson's peachbrush, and Wyoming big sagebrush. This pedon is associated with ecological site R026XY010NV, Loamy 10-12" P.Z.

DISTRIBUTION AND EXTENT: Western and central Nevada and northeastern California. These soils are moderately extensive. The original series concept is in MLRA 26, while the main acreage is in MLRA 28B.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.

SERIES ESTABLISHED: Washoe County (South Part), Nevada 1980.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 38 cm (A1, A2, A3, and Bt1 horizons).
Argillic horizon - The zone from 25 to 114 cm (Bt1, Bt2, and Bt3 horizons).
Paralithic contact - The boundary at 114 cm to underlying soft, weathered bedrock (2Cr layer).
Particle-size control section - The zone from 25 to 75 cm (Bt1 and Bt2 horizons and part of the Bt3 horizon).

ADDITIONAL DATA: User Pedon ID 2006NV031021.

National Cooperative Soil Survey
U.S.A.