LOCATION ORHOOD                  CA

Established Series
Rev. JJJ/TAC/WCL/JBF
07/2011

ORHOOD SERIES

The Orhood series consists of shallow, well drained soils that formed in material derived from extrusive igneous rock. They are on mountains and hills. Slopes range from 2 to 50 percent. The mean annual precipitation is about 300 mm and the mean annual temperature is 9 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Aridic Lithic Argixerolls

TYPICAL PEDON: Orhood very cobbly loam - on a 6 percent south facing slope under big sagebrush, squirreltail, cheatgrass and western juniper at 1,405 meters elevation. (Colors are for dry soil unless otherwise stated. When described on July 28, 1982, the soil was dry throughout.)

A--0 to 10 cm; grayish brown (10YR 5/2) very cobbly loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; common very fine and fine interstitial pores; 10 percent stones, 34 percent cobbles and 6 percent gravel, neutral (pH 7.0); clear smooth boundary. (8 to 13 cm thick)

BAt--10 to 20 cm; grayish brown (10YR 5/2) very cobbly loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; few very fine and fine interstitial and tubular pores; few thin clay films bridging sand grains; 10 percent stones; 30 percent cobbles and 10 percent gravel; neutral (pH 7.0); clear wavy boundary. (8 to 13 cm thick)

Bt1--20 to 28 cm; grayish brown (10YR 5/2) very cobbly clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; hard, firm, sticky and plastic; common very fine, fine and few medium roots; few very fine and fine tubular pores; common moderately thick clay films on faces of peds; 10 percent stones, 30 percent cobbles and 10 percent gravel; neutral (pH 7.0); gradual wavy boundary. (5 to 13 cm thick)

Bt2--28 to 36 cm; yellowish brown (10YR 5/4) very cobbly clay loam, dark yellowish brown (10YR 3/4) moist; moderate medium angular blocky structure; hard, firm, sticky and plastic; common very fine, fine and few medium roots; few very fine and fine tubular pores; many moderately thick clay films on faces of peds and in pores; 10 percent stones, 30 percent cobbles and 10 percent gravel; neutral (pH 7.0); clear wavy boundary. (5 to 13 cm thick)

Bt3--36 to 41 cm; light yellowish brown (10YR 6/4) very cobbly loam, dark yellowish brown (10YR 4/4) moist; moderate medium angular blocky structure; slightly hard, friable, slightly sticky and plastic; common fine roots; common very fine and fine tubular pores; common moderately thick clay films on faces of peds; 10 percent stones, 30 percent cobbles, 10 percent gravel; neutral (pH 7.0); abrupt wavy boundary. (3 to 8 cm thick)

R--41 cm; hard extrusive igneous rock.

TYPE LOCATION: Siskiyou County, California; about 11 miles east of Macdoel, 350 feet west of dirt road; 1,584 feet north and 1,884 feet east of the southwest corner of sec. 30, T.46 N., R.2 E.; latitude 4l degrees 47 minutes 47 seconds N and longitude 121 degrees 47 minutes 41 seconds longitude; NAD 83

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry; moist in winter and spring; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 9 to 11 degrees C.
Depth to extrusive igneous rock: 36 to 50 cm.

Particle-size control section - Clay content: Averages 20 to 27 percent.
Rock fragments : 35 to 55 percent.
Stones : 5 to 10 percent.
Cobbles: 20 to 30 percent.
Gravel: 10 to 15 percent.

A horizon:
Hue: 10YR or 7.5YR.
Chroma 2 or 3.
Organic matter: 1 to 3 percent.

Bt horizons
Hue: 10YR or 7.5YR.
Value: 4 through 6 dry.
Chroma: 2 through 4.
exture: Cobbly loam or very cobbly clay loam.
Clay content ranges from: 18 to 32 percent.

COMPETING SERIES: These are the Argabak, Bellehelen, Brier, Duco, Horseflat, Nuhelen, Ocud, Reywat, and Upatad series.

Argabak soils are less than 36 cm deep to bedrock. Bellehelen, Brier and Nuhelen are moist for 10 to 20 days cumulative between July to October due to convection storms. Duco soils have a soil temperature of 10 to 12 degrees C and average 27 to 35 percent clay in the particle-size control section. Horseflat soils lack secondary silica coatings over the bedrork. Ocud soils have a lithic contact within 36 cm. Reywat soils are dry 60 to 80 days have Bt horizons that are typically slightly alkaline or moderately alkaline and are calcareous in the lower part. Upatad soils have 27 to 35 percent clay in the particle-size control section.

GEOGRAPHIC SETTING: Orhood soils are on mountains and hills. Slopes are 2 to 50 percent. The soils formed in material derived from extrusive igneous rock. Elevation is 1,250 to 1,985 meters. The climate is semiarid with warm dry summers and cold moist winters. Mean annual precipitation is 250 to 400 mm. Snowfall is 250 to 500 mm. Mean annual temperature is 7 to 10 degrees C. Frost-free season is 50 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dehill, Hedox, Porterfield, Ricketts, and Searles soils. Dehill soils are greater than 150 cm deep. Hedox soils are 50 to 100 cm deep to a paralithic contact. Porterfield soil are loamy and over a paralithic contact. Ricketts and Searles soils are 10 to 100 cm deep.

DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderately slow permeability.

USE AND VEGETATION: Orhood series are used for grazing and juniper wood products such as firewood and fence posts. Vegetation is western juniper an understory of mountain big sagebrush, bluebunch wheatgrass, Idaho fescue, thumber needlegrass, and rubber rabbitbrush.

DISTRIBUTION AND EXTENT: North Central California. These soils are moderately extensive. MLRA is 21.

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

SERIES ESTABLISHED: Siskiyou County, California; Butte Valley-Tule Lake Soil Survey 1988.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon--Zone from the surface to 28 cm (A, BAt, Bt1 horizons).
Argillic horizon--Zone from 10 to 41 cm (BAt, Bt1, Bt2, Bt3 horizons).
Lithic contact--The contact at 41 cm (R layer).
Particle-size control section -- The zone from 10 to 41 cm (BAt, Bt1, Bt2, Bt3 horizons).

Classification was updated to 11th edition on 07/2011 changed Lithic Argixerolls to Aridic Lithic Argixerolls.

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National Cooperative Soil Survey
U.S.A.