LOCATION HOTAW CA

Established Series
Rev. JHR/GMK/LCL/AJT/ET/SS/DWB/AGB/TKK/JTW
03/2023

HOTAW SERIES

The Hotaw series consists of moderately deep, well drained soils formed in material weathered from granitic rocks. These soils are on hills and mountains. Slopes are 2 to 75 percent. Mean annual precipitation is about 1400 mm and mean annual air temperature is about 13 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Ultic Haploxeralfs

TYPICAL PEDON: Hotaw coarse sandy loam on a west facing, linear, slope of 25 percent under ponderosa pine, California black oak, canyon live oak, and mountain misery. (Colors are for dry soil unless otherwise noted. When described on May 20, 1966 the soil was moist below 34 cm.)

Oi--0 to 3 cm; litter and duff.

A--3 to 34 cm; grayish brown (10YR 5/2) coarse sandy loam, dark brown (10YR 3/3) moist; 11 percent clay; moderate fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine, fine, and medium roots; many very fine and fine tubular and interstitial pores; slightly acid (pH 6.1); clear wavy boundary. (15 to 30 cm thick)

BAt--34 to 59 cm; pale brown (10YR 6/3) coarse sandy loam, brown (10YR 4/3) moist; 15 percent clay; moderate medium subangular blocky structure; hard, friable, nonsticky and nonplastic; many very fine, fine and medium roots; many very fine and fine tubular and interstitial pores; few thin clay films line pores; moderately acid (pH 5.9); clear smooth boundary. (20 to 30 cm thick)

Bt--59 to 91 cm; light brown (7.5YR 6/4) sandy clay loam, brown (7.5YR 4/4) moist; 28 percent clay; moderate medium and coarse subangular blocky structure; very hard, firm, sticky and slightly plastic; many fine and medium roots; common very fine and fine tubular pores; many moderately thick clay films on ped faces, lining pores and as bridges; strongly acid (pH 5.5); clear wavy boundary. (20 to 40 cm thick)

Cr--91 to 117 cm; weathered granodiorite.

TYPE LOCATION: El Dorado County, California; 0.5 miles east of Aukum; 0.1 mile northeast of southwest corner of section 12, T. 8 N., R. 11 E. USGS 7.5 minute topographic quadrangle: Aukum, California. WGS84 decimal degrees: 38.5548996 latitude, -120.7224444 longitude. UTM Zone 10 698459 meters E, 4269844 meters N, NAD83.

RANGE IN CHARACTERISTICS:
Soil temperature: the mean annual soil temperature at a depth of 50 cm beneath the mineral soil surface is 11 to 15 degrees C. The difference between mean summer and winter soil temperatures is greater than 6 degrees C. The soils have a mesic temperature regime.

Soil moisture: the soil moisture control section is dry in all parts from about June to October. The soils have a xeric moisture regime.

Diagnostic Feature(s):
Ochric epipedon thickness: 6 to 35 cm
Argillic horizon thickness: 30 to 75 cm
Depth to paralithic contact: 50 to 100 cm

Particle size control section weighted averages:
Clay content: 18 to 35 percent
Rock fragments: 0 to 35 percent gravel, cobbles and stones

A horizon:
Hue: 7.5YR, 10YR
Value: 4 to 6 dry; 3 or 4 moist
Chroma: 2 to 8 dry; 2 to 4 moist
Textures: sandy loam, coarse sandy loam, fine sandy loam, loam
Clay content: 10 to 25 percent
Rock fragments: 0 to 15 percent
Reaction: moderately acid to slightly acid

The lower boundary of the A horizon is gradual or there is a transitional horizon.

Bt horizon:
Hue: 7.5YR, 10YR
Value: 4 to 6 dry; 3 to 5 moist
Chroma 2 to 8 dry; 2 to 8 moist
Textures: sandy clay loam, clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 35 percent
Reaction: strongly acid to slightly acid
Coarse and Very Coarse sand content: 16 to 26 percent

Some pedons have a BC or BCt horizon above the paralithic contact.

COMPETING SERIES: These are the Bigridge, Cohasset, Holland, Hospiter (MLRA 5), Millerridge, Minniecreek, Pasturerock (MLRA 4B), Sitton (MLRA 2), Speaker (MLRA 5) and Willakenzie (MLRA 2) soils. The Bigridge, Cohasset, Holland, Hospiter, Pasturerock and Sitton soils do not have a root-restrictive bedrock contact within 100 cm. Millerridge soils have significant amounts of magnesium-rich minerals and form from ultramafic rock. Minniecreek soils have coarse plus very coarse sand content less than 15 percent in the particle size control section. Speaker soils are dry in all parts of the soil moisture control section for 60 to 90 days following the summer solstice. Willakenzie soils are dry in all parts of the soil moisture control section for 45 to 60 days following the summer solstice.

GEOGRAPHIC SETTING: Hotaw soils are on linear to convex backslopes and shoulders of mountains and hills at elevations of 495 to 1600 meters. In some areas with north aspects the elevation is as low as 350 meters. Slope is 2 to 75 percent. Rock outcrops are common. The underlying rock is quartz diorite or granodiorite. The climate is Mediterranean with warm, dry summers and cool, moist winters. Mean annual precipitation is 750 to 1800 mm, of which 2 to 15 percent occurs as snow. Mean annual air temperature is 11 to 16 degrees C, average January temperature is about 6 degrees C, average July temperature is about 23 degrees C. Frost-free season is 165 to 260 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chaix, Chawanakee, Holland, Shaver and Musick soils. Chaix, Chawanakee and Shaver soils do not have argillic horizons. Chaix soils occur on backslopes of mountains and hills. Chawanakee soils occur on steeper portions of backslopes, as well as shoulders and summits of mountains and hills and are 25 to 50 cm to a paralithic contact. Shaver soils occur on backslopes of mountains and hills and are 100 to 150 cm to a paralithic contact. Holland (backslopes of mountains and hills) and Musick (backslopes, shoulders and summits of mountains and hills) do not have root-restrictive bedrock contacts within 150 cm.

DRAINAGE AND PERMEABILITY: Well drained; saturated hydraulic conductivity is moderately high to high in the near-surface horizons and moderately high in the argillic horizon. Saturated hydraulic conductivity of the weathered bedrock is low to moderately high.

USE AND VEGETATION: Primarily used for timber production. Vegetation is ponderosa pine, sugar pine, Douglas-fir, incense-cedar, California black oak, and canyon live oak with an understory of shrubs, grasses, and forbs.

DISTRIBUTION AND EXTENT: Sierra Nevada Mountains of California; MLRA 22A. The soils are of moderate extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Nevada County Area, California, 1970.

REMARKS:

Particle size control section for this pedon: 34 to 84 cm (BAt and upper portion of Bt horizon)

Diagnostic horizons and features recognized in this pedon:
Ochric epipedon: 0 to 34 cm
Argillic horizon: 34 to 91 cm
Paralithic contact: 91 cm

ADDITIONAL DATA:

NASIS User Pedon ID: 1968CA017003

Soil classified using the 13th Edition of the Keys to Soil Taxonomy.

National Cooperative Soil Survey
U.S.A.