LOCATION HAYSUM CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Pachic Argixerolls
TYPICAL PEDON: Haysum gravelly loam--on a northeast linear slope of 1 percent under hairgrass, starthistle, and Oregon white oak at an elevation of 2,525 feet. (Colors are for dry soil unless noted otherwise. When described on August 19, 1981 the soil was dry above 25 inches, and very slightly moist below that depth.)
A1--0 to 5 inches; brown (10YR 5/3) gravelly loam, dark brown (10YR 3/3) moist; strong medium and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; few fine, many very fine roots; many fine and very fine tubular pores; 30 percent gravel; slightly acid (pH 6.5); clear wavy boundary. (5 to 8 inches thick)
A2--5 to 15 inches; yellowish brown (10YR 5/4) gravelly loam, dark brown (10YR 3/3) moist; weak medium, fine, and very fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and very fine roots; few fine, common very fine tubular pores; 20 percent gravel; slightly acid (pH 6.5); gradual wavy boundary. (0 to 13 inches thick)
Bt1--15 to 27 inches; yellowish brown (10YR 5/4) gravelly clay loam, dark brown (10YR 3/3) moist; moderate medium and fine subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few coarse and medium, common fine and very fine roots; few medium, common fine and very fine tubular pores; common thin clay films lining pores and on ped faces; 20 percent gravel; slightly acid (pH 6.5); gradual wavy boundary. (10 to 14 inches thick)
Bt2--27 to 48 inches; yellowish brown (10YR 5/4) gravelly clay loam, brown (10YR 4/3) moist; weak medium and fine subangular blocky structure; very hard, firm, sticky and plastic; common medium, fine and very fine roots; few very fine tubular pores; many thin clay films lining pores and on ped faces; 25 percent gravel; slightly acid (pH 6.5); gradual wavy boundary. (10 to 19 inches thick)
Bt3--48 to 66 inches; yellowish brown (10YR 5/4) gravelly clay loam, dark yellowish brown (10YR 4/4) moist; weak medium and fine subangular blocky structure; very hard, firm, sticky and plastic; few fine and very fine roots; few very fine tubular pores; many thin clay films lining pores and on ped faces; 30 percent gravel; slightly acid (pH 6.5); gradual wavy boundary. (17 to 19 inches thick)
Bt4--66 to 71 inches; yellowish brown (10YR 5/4) very gravelly sandy clay loam, dark yellowish brown (10YR 4/4) moist; hard, friable, sticky and plastic; few very fine roots; few very fine tubular pores; few thin clay films lining pores and on ped faces; 55 percent gravel; slightly acid (pH 6.5).
TYPE LOCATION: Trinity County, California; about 5 1/2 miles northeast of Hayfork, California; 0.2 mile south of Highway 3 on Summit Creek Road, 200 feet east of the road; 100 feet west, 300 feet north of the southeast corner of section 34, T. 32 N., R. 11 W. Hayfork Summit Quadrangle.
RANGE IN CHARACTERISTICS: The particle-size control section averages 15 to 35 percent gravel and 27 to 35 percent clay. The mollic epipedon is 20 to 40 inches thick. The mean annual soil temperature is 53 to 59 degrees F. The soil moisture control section between the depths of 8 and 16 inches is dry in all parts from about mid July to mid October (about 85 to 95 days). The soil temperature at a depth of 20 inches exceeds 41 degrees F from about mid March to late December (about 280 to 300 days), and exceeds 47 degrees F from about mid April to late November. Base saturation ranges from 75 to 85 percent (sum of cations) in the upper 30 inches of the profile.
The A horizon is 10YR 5/3, 5/4, or 3/3. Moist color is 10YR 3/3 or 3/2. It is loam or gravelly loam. It has 20 to 27 percent clay and 5 to 35 percent gravel. It is slightly acid or neutral.
The Bt horizon is 10YR 5/4, 5/3, or 3/3. Moist color is 10YR 3/3, 4/3, 4/4, or 3/2. Moist color is 10YR 3/3 or 3/2 to 20 inches or more. It is gravelly clay loam, gravelly loam, very gravelly sandy clay loam, clay loam, or very gravelly clay loam. The Bt horizon has 15 to 35 percent gravel in the upper part, but may have up to 65 percent gravel in lower part. It has 25 to 35 percent clay, 5 to 8 percent more clay than the A horizon.
COMPETING SERIES: These are the Adieux (T), Banning, Blockhouse (T), Coolbrith, Dotta, Drews, Gorman, Grosswell (T), Harriman, Henhill (T), Lonkey (T), Pumphouse (T), Robinette, Supan, Van Dusen, Waha, Wapinitia, Wockum (T), and Yaxon series. The Adieux, Lonkey, and Waha soils are 20 to 40 inches deep over a lithic contact. The Banning soils have mottles in the A and B horizons, and are somewhat poorly drained. The Blockhouse, Coolbrith, Dotta, Drews, Henhill, Pumphouse, Robinette, Van Dusen and Wapinitia soils have mean annual soil temperature less than 52 degrees F. Gorman soils are dry for 180 to 195 days when the soil temperature is greater than 41 degrees F. Henhill and Pumphouse soils have Bk horizons. Harriman soils have sola less than 40 inches thick. Supan soils are 40 to 60 inches deep over a lithic contact and have 7.5YR and 5YR colors.
GEOGRAPHIC SETTING: The Haysum soils are on stream terraces and alluvial fans. Elevation is 1,900 to 2,600 feet. Slopes are 0 to 9 percent. These soils formed in mixed alluvium. The climate is characterized by warm, dry summers and moist, cool winters. Mean annual precipitation is 30 to 40 inches. Snowfall ranges from 6 to 20 inches. Mean January temperature is about 38 degrees F. Mean July temperature is about 72 degrees F. Mean annual air temperature is 50 to 57 degrees F. The frost-free period is 90 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Crefork and Carrcreek series. Crefork soils lack a mollic epipedon and are on hills. Carrcreek soils have greater than 35 percent rock fragments in the particle-size control section.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderate permeability.
USE AND VEGETATION: This soil is used for hayland, pastureland, woodland, and homesite development. Native vegetation consists of perennial grasses with widely spaced Oregon White oak. There are isolated stands of Oregon white oak and ponderosa pine.
DISTRIBUTION AND EXTENT: The soils are not extensive. They occur in Hayfork Valley in the Klamath Mountains of Northern California. MLRA is 5.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Trinity County, California, Weaverville Area, 1990. Name coined from Hayfork Summit.
REMARKS: The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon--the zone from the surface to a depth of 27 inches (A1, A2, Bt1),
Argillic horizon--the zone from 15 to 71 inches (Bt1, Bt2, Bt3, Bt4),
Particle-size control section--the zone from 15 to 35 inches (Bt1, Bt2).