LOCATION WITCHER CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Andic Haploxeralfs
TYPICAL PEDON: Witcher sandy loam on a northeast facing 13 percent slope under a cover of mixed conifers, greenleaf manzanita and squawcarpet at an elevation of 5500 feet. (Colors are for dry soil unless otherwise stated. When described October 3, 1985, the soil was moist to 17 inches.)
Oi--2 to 0 inches; recent and decomposed pine litter.
A1--0 to 2 inches; brown (10YR 5/3) sandy loam, dark brown (7.5YR 3/2) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine roots; common very fine interstitial pores; 10 percent gravel; NaF pH 10.5; slightly acid (pH 6.5); abrupt smooth boundary.
A2--2 to 4 inches; brown (7.5YR 5/4) sandy loam, dark brown (7.5YR 3/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common fine roots; common very fine interstitial pores; 10 percent gravel; NaF pH 11.0; slightly acid (pH 6.5); abrupt smooth boundary. (Combined thickness of the A horizon is 4 to 8 inches).
Bt1--4 to 10 inches; brown (7.5YR 5/4) sandy clay loam, dark brown (7.5YR 3/4) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and few medium roots; common very fine tubular pores; few thin clay films in pores; 10 percent gravel; NaF pH 8.6; slightly acid (pH 6.5); clear smooth boundary. (5 to 8 inches thick)
2Bt2--10 to 17 inches; brown (7.5YR 5/4) sandy clay loam, dark reddish brown (5YR 3/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and few medium and coarse roots; common very fine and few fine tubular pores; few thin clay films in pores; 10 percent gravel; NaF pH 8.6; slightly acid (pH 6.5); clear smooth boundary.
2Bt3--17 to 24 inches; brown (7.5YR 5/4) sandy clay loam, dark reddish brown (5YR 3/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and plastic; common fine and few medium and coarse roots; common very fine and few fine tubular pores; common thin clay films in pores; 10 percent gravel; NaF pH 8.6; slightly acid (pH 6.5); clear smooth boundary.
2Bt4--24 to 36 inches; brown (10YR 5/3) sandy clay loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and plastic; common fine and few medium roots; common very fine and few fine tubular pores; common thin clay films in pores; 10 percent gravel; NaF pH 8.6; slightly acid (pH 6.5); gradual wavy boundary. (Combined thickness of the 2Bt horizon is 23 to 29 inches thick.)
3BCt--36 to 47 inches; brown (10YR 5/3) very gravelly clay loam, brown (10YR 4/3) moist; moderate fine subangular blocky structure; hard, firm, slightly sticky and plastic; few fine roots; common very fine tubular pores; common thin clay films in pores; 50 percent weathered gravel; NaF pH 8.6; slightly acid (pH 6.5); gradual wavy boundary. (8 to 15 inches thick.)
3Cr--47 inches; soft weathered andesite.
TYPE LOCATION: Modoc County, California; about 8 miles southeast of Canby on Hermit Butte; 800 feet east and 150 feet south of the northwest corner of sec. 2, T. 40 N., R. 10 E., Canby SE (Hermit Butte) quadrangle (7.5 minute series).
RANGE IN CHARACTERISTICS: Depth to a paralithic contact is 40 to 60 inches. The mean annual soil temperature is 41 to 46 degrees F. The soil temperature exceeds 41 degrees F. from about May to about November (185 days) and exceeds 47 degrees F. from about July to about October. The soil moisture control section is dry in all parts from about June to about September (75 to 90 days) and is moist in all parts from early November to early June. The particle size control section averages 27 to 35 percent clay, 50 to 60 percent sand and 0 to 5 percent rock fragments (mostly gravel). NaF pH is 11.0 to 8.6 and decreases with depth. Reaction is slightly acid to moderately acid. Base saturation by sum of cations ranges from 50 to 70 percent and decreases with depth. Organic matter ranges from 2 to 4 percent to a depth of 10 inches and decreases regularly with depth. Aluminum and 1/2 iron (by ammonium oxalate) range from 0.5 to 1.0. Volcanic glass content ranges from 5 to 15 percent.
The A1 horizon color is 10YR 4/3 or 5/3. Moist color is 7.5YR 3/2 or 5YR 3/2. Clay content ranges from 12 to 15 percent. Rock fragments, mostly gravel, range from 0 to 15 percent.
The A2 horizon color is 7.5YR 5/4 or 6/4. Moist color is 7.5YR 3/4 or 5YR 3/4. Clay content ranges from 15 to 18 percent. Rock fragments, mostly gravel, range from 0 to 15 percent.
The Bt and 2Bt horizon color is 7.5YR 5/4, 4/4 or 5YR 5/4; and 10YR 5/3 in the lower part. Moist color is 7.5YR 3/4 or 5YR 3/4 and 10YR 4/3 in the lower part. Clay content ranges from 20 to 35 percent. Rock fragments, mostly gravel range from 0 to 15 percent.
The 3BCt horizon color is 10YR 5/3, 4/2, 5/4; 5YR 3/3 or 7.5YR 5/4. Moist color is 10YR 4/3, 3/2, 3/4; 5YR 4/4 or 7.5YR 3/4. Texture is very gravelly clay loam or very gravelly sandy clay loam. Clay content ranges from 27 to 35 percent. Rock fragments, mostly weathered gravel, range from 35 to 90 percent.
Andic property data (see remarks for explanation):
Depth P-ret B.D. pH NaF Glass Alo Feo 15 barH20
0-2 68 0.92 10.5 9 1.03 0.90 21.2
2-4 73 0.84 11.0 9 0.85 0.94 16.8
4-10 58 ND 8.6 8 0.61 0.84 16.8
10-17 50 1.11 8.6 4 0.47 0.99 18.4
17-24 46 ND 8.6 ND 0.37 1.06 18.8
24-36 46 1.15 8.6 ND 0.35 0.96 20.0
36-47 44 ND 8.6 ND 0.29 0.73 19.7
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: Witcher soils are on mountains. Slopes are 2 to 50 percent. These soils formed in tephra. Elevation is 4600 to 6500 feet. The climate is semiarid with warm dry summers and cold moist winters. Mean annual precipitation is 18 to 20 inches. Snowfall is 48 to 60 inches. The mean annual temperatures is 40 to 45 degrees F. The mean January temperature is about 32 degrees F. The mean July temperature is about 60 degrees F. Frost-free period is 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Canyoncreek, Gosch, and Hermit soils. Canyoncreek soils are on mountains, are deep to paralithic contact, have thick mollic epipedon, are medial over loamy-skeletal and are cryic. Gosch soils are on mountains, are deep to paralithic contact, have ochric epipedon and are loamy-skeletal. Hermit soils are on mountains, are deep to paralithic contact, have thick mollic epipedon, are medialover fine-loamy and are cryic.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderately slow permeability.
USE AND VEGETATION: This soil is used for timber production. Small areas are used for urban development. The natural vegetation is white fir, ponderosa pine, incense cedar, greenleaf manzanita and squawcarpet, lupine and mulears, lupine and mulears.
DISTRIBUTION AND EXTENT: Northeastern California. The soils are not extensive, about 4000 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Modoc County, Intermountain Soil Survey Area, California 1994. Source of name is Witcher Creek. MLRA is 22.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Rock fragments (mostly gravel) on the soil surface, range from 0 to 10 percent.
Ochric epipedon - 0 to 4 inches (A1, A2).
Argillic horizon - 4 to 47 inches (Bt1, 2Bt2, 2Bt3, 2Bt4, 3BCt).
Paralithic contact - the boundary t 47 inches (3Cr).
Andic properties data definitions:
P-ret: phosphate retention of the less than 2mm fraction.
B.D.: bulk density of the less than 2mm fraction measured on an oven dry basis.
pH NaF: pH of soil mixed with saturated sodium floride solution.
Glass: percent volcanic glass.
Alo: acid-oxalate-extractable aluminum of the less than 2mm fraction.
Feo: acid-oxalate-extractable iron of the less than 2mm fraction.
15 bar H20: dried 1500 kPa water retention as a percent.
Data elements with a * are estimated.
NC: not calculated.
ND: not done.
ADDITIONAL DATA: This pedon was characterized by UC Davis in 1988. Sample number is 88CA-089-02-(1-7) unpublished, Lab #1688