LOCATION HOHMANN CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Typic Haploxerepts
TYPICAL PEDON: Hohmann gravelly light clay loam - forested (Colors for dry soils unless otherwise stated)
01--2 1/2 to 0 inches; Loose litter of leaves over very thin partly decomposed organic matter. (0 to 3 inches thick)
A1--0 to 4 inches; Reddish gray (5YR 5/2) gravelly light clay loam, dark reddish gray (5YR 4/2) moist; moderate medium granular structure; slightly hard, friable, slightly sticky, slightly plastic; few fine roots; many very fine and fine pores; slightly acid (pH 6.2); gradual smooth boundary. (2 to 8 inches thick)
B2--4 to 29 inches; Pinkish gray (7.5YR 6/2) gravelly clay loam, reddish gray (5YR 5/2) moist; weak fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common fine, few medium and coarse roots; many fine tubular pores; medium acid (pH 6.0); gradual smooth boundary. (12 to 30 inches thick)
C1--29 to 33 inches; Pinkish gray (7.5YR 6/2) very gravelly and stony heavy clay loam, brown (7.5YR 5/2) moist; massive, hard, firm, sticky and plastic; few medium and coarse roots; few fine and medium tubular pores; slightly acid (pH 6.2). (4 to 8 inches thick)
R--33 to 36 inches; Purplish colored, hard, fractured, very slightly weathered metavolcanic rock.
TYPE LOCATION: Glenn County, California 1/8 mile south of Twin Springs on the east side of St. John Mountain and 1/4 mile west and 1.3 miles south of the SE corner Sec. 32; T18N, R7W.
RANGE IN CHARACTERISTICS: Solum thickness is about 14 to 38 inches and the soil is about 20 to 40 inches deep to basic metavolcanic bedrock. Mean annual soil temperature ranges from 53 to 57 degrees F. Mineralogy is mixed and the soils are dry most years for more than 60 consecutive days during the summer. The A horizon colors are in 5YR and 7.5YR hues and have values of 4 through 6 dry and 3 or 4 moist. Chromas are 2 dry or moist. Texture ranges from heavy loam to light clay loam. Structure is moderate to weak granular, consistence is slightly hard to hard, friable, and slightly sticky and slightly plastic. Reaction is slightly acid. The B2 horizon colors are in the 7.5YR hue with values of 5 or 6 dry and 4 or 5 moist. Chromas are 2 or 3. Texture ranges from light clay loam to clay loam and structure from weak or moderate subangular blocky to moderate granular. Consistence is hard, friable to firm and slightly plastic and slightly sticky to plastic and sticky. Reaction generally is medium acid.
COMPETING SERIES: These include the Barron, Kerby, Laughlin, Madonna, Masterson, McCarthy, Morical and Neuns series. The Kerby soils have dark brown A horizons, loam textured B2 horizons and lack R layers. The Laughlin soils have brown A horizons and strongly acid B2 horizons. The Barron soils are very deep, have dark grayish brown A horizons, and sandy loam B2 horizons. The Madonna soils have pale brown A horizons and medium and strongly acid B2 horizons. The Masterson soils have brown, strongly acid A horizons and very strongly acid B2 horizons. The McCarthy soils have brown and dark brown A horizons and gravelly sandy loam B2 horizons. The Morical soils have pale brown mildly alkaline B2 horizons. The Neuns soils have dark brown A horizons and yellowish brown medium and strongly acid B2 horizons.
SETTING: The Hohmann soils are in steep and very steep mountainous uplands on basic metavolcanic rocks. Elevations are about 3,500 to 4,500 feet. The climate is mesothermal with mean annual rainfall of 35 to 55 inches, with warm dry summers and cold moist winters. Mean annual temperature is about 50 to 54 degrees F., the average January temperature about 39 degrees F., and average July temperature about 70 degrees F.
PRINCIPAL ASSOCIATED SOILS: The Hohmann soils occur in the same general areas as the very deep, red and reddish yellow Boomer soils, the deep pale brown, strongly acid Hugo soils, the very deep, reddish brown Josephine soils, and Neuns soils.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained, moderately rapid permeability and rapid runoff.
USE AND VEGETATION: Used for timber production. Native vegetation is ponderosa pine, sugar pine, Douglas-fir, white fir, black oak and canyon live oak.
DISTRIBUTION AND EXTENT: Mountainous areas of Glenn Co., California. The soils are inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Glenn Co. California, November, 1957. REMARKS: The Hohmann series was formerly classified in the Regosol group.
OSED scanned by SSQA. Last revised by state on 11/68.