LOCATION SPROULISH CA
Established Series
REV: JWH/ET
03/2013
SPROULISH SERIES
The Sproulish series consists of very deep, well drained soils formed in colluvium and residuum derived from sandstone, mudstone, and metasedimentary rocks. Sproulish soils are on mountains. Slopes range from 15 to 75 percent. Mean annual precipitation is about 2160 mm and the mean annual temperature is about 11 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, isomesic Typic Dystrustepts
TYPICAL PEDON: Sproulish gravelly silt loam on a west facing 35 percent slope under Douglas-fir and tanoak at an elevation of 268 meters. (Colors are for dry soil unless otherwise noted.) When described on 04/30/04, the soil was moist to 200 cm.
Oi--0 to 4 centimeters; dark brown (7.5YR 3/2) slightly decomposed plant material consisting of needles and leaves of Douglas-fir and tanoak, very dark gray (7.5YR 3/1) moist; about 85 percent fiber, 45 percent rubbed; loose, nonsticky and nonplastic; 2 percent gravel; moderately acid (pH 5.6); abrupt smooth boundary. (0 to 5 centimeters thick)
A--4 to 15 cm; light brown (7.5YR 6/3) gravelly silt loam, brown (7.5YR 4/3) moist; moderate medium granular structure; moderately hard, friable, slightly sticky and slightly plastic; common very fine roots throughout; 17 percent gravel; moderately acid (pH 6.0); abrupt smooth boundary. (5 to 30 centimeters thick)
Bt1--15 to 32 cm; light brown (7.5YR 6/4) clay loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common fine and very fine roots and few medium roots throughout; common very fine, fine, and medium tubular pores; many distinct clay films on all faces of peds; 14 percent gravel; moderately acid (pH 5.8); clear smooth boundary.
Bt2--32 to 53 cm; light brown (7.5YR 6/4) gravelly loam, brown (7.5YR 4/4) moist; moderate fine and medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common fine roots and few medium roots throughout; few very fine tubular pores; many distinct clay films on all faces of peds; 16 percent gravel; moderately acid (pH 5.8); gradual smooth boundary. (combined thickness of the upper B horizons is 40 to 110 centimeters)
Bt3--53 to 120 cm; light yellowish brown (10YR 6/4) clay loam, yellowish brown (10YR 5/4) moist; moderate medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few medium roots and common very fine roots throughout; common very fine tubular pores; many distinct clay films on all faces of peds; 10 percent gravel; strongly acid (pH 5.5); gradual smooth boundary.
Bt4--120 to 160 cm; light brown (7.5YR 6/4) silty clay loam, brown (7.5YR 5/4) moist; moderate fine and medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few medium and common very fine roots throughout; few very fine tubular pores; many distinct clay films on all faces of peds; 11 percent gravel; strongly acid (pH 5.4); gradual wavy boundary.
Bt5--160 to 200 cm (63 to 79 inches); very pale brown (10YR 7/4) silty clay loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common distinct clay films on all faces of peds; 11 percent gravel; strongly acid (pH 5.3). (combined thickness of the lower B horizons is 30 to 150 centimeters)
TYPE LOCATION: Humboldt County, California; about 6.5 kilometers southwest of the town of Garberville, CA, USGS quadrangle Garberville, CA; 40 degrees 03 minutes 47 seconds north latitude and 123 degrees 51 minutes 07 seconds west; zone 10 427440mE, 4434917mN; NAD 83.
RANGE IN CHARACTERISTICS:
Soil Temperature: The mean annual soil temperature at 50 centimeters is 9 to 11 degrees C. (48 to 51 degrees F) and the difference between mean summer and mean winter soil temperatures is less than 6 degrees C. The soil has an isomesic soil temperature regime.
Soil Moisture: The soil moisture control section is dry in some or all parts for 90 or more cumulative days in normal years and it is moist in some part for more than 180 cumulative days or for 90 or more consecutive days per year. The soil has an ustic soil moisture regime.
Surface Fragments: 0 to 34 percent gravel
Base Saturation: Less than 60 percent by ammonium acetate in all horizons between 25 and 75 centimeters.
Surface Fragments: 0 to 20 percent gravel
Particle size control section (weighted average):
Rock fragments: 0 to 34 strongly cemented mudstone and sandstone gravel
Pararock fragments: 0 to 34 percent moderately cemented mudstone and sandstone paragravel
Clay content: 24 to 34 percent
A horizon:
Hue: 7.5YR or 10YR
Value: 4 through 6, 2 through 4 moist
Chroma: 1 through 4, dry and moist
Texture of fine earth: loam, silt loam
Clay content: 18 to 26 percent
Rock fragments: 0 to 34 percent gravel
Pararock fragments: 0 to 14 percent paragravel
Reaction: moderately to slightly acid
Upper Bt or Bw horizons:
Hue: 7.5YR, 10YR, or 2.5Y
Value: 5 or 6, 2 to 4 moist
Chroma: 3 or 4, dry or moist
Texture of fine earth: loam, silt loam, clay loam, silty clay loam, or sandy clay loam
Clay content: 20 to 30 percent
Rock fragments: 0 to 34 percent gravel
Pararock fragments: 0 to 34 percent paragravel
Reaction: slightly to strongly acid
Lower Bt or Bw horizons:
Hue: 7.5YR, 10 YR, or 2.5Y
Value: 5 through 7, 3 through 5 moist
Chroma: 3 through 6, dry or moist
Texture of fine earth: loam, silt loam, clay loam, silty clay loam, or sandy clay loam
Clay content: 20 to 36 percent
Rock fragments: 0 to 34 percent gravel
Pararock fragments: 0 to 59 percent paragravel
Reaction: strongly to moderately acid
Some pedons have a C horizon below 150 centimeters:
Hue: 7.5YR, 10 YR, or 2.5Y
Value: 5 through 7, 3 or 4 moist
Chroma: 4 through 6, dry or moist
Texture of fine earth: sandy loam, loam, silt loam
Clay content: 14 to 26 percent
Rock fragments: 5 to 89 percent gravel
Pararock fragments: 5 to 89 percent paragravel
Reaction: strongly to moderately acid
COMPETING SERIES: These are the
Alambique (CA) and
Nye (T) series. Alambique soils have a paralithic contact between 50 and 100 centimeters. Nye soils have consolidated alluvium between 100 and 150 centimeters.
GEOGRAPHIC SETTING: Sproulish soils are on linear to concave or slightly convex positions on summits, shoulders, and backslopes of mountain slopes and ridges. Slopes are 15 to 75 percent. Elevations are 185 to 730 meters. These soils formed in colluvium and residuum derived from sandstone, mudstone, and metasedimetary rocks. The climate is subhumid with warm, dry summers with a marine layer influence and cool, wet winters. Mean annual precipitation is 1525 to 3050 millimeters. The mean annual temperature is 10 to 12 degrees C. Frost free season is about 240 to 280 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Canoecreek (CA),
Gibsoncreek (CA), and
Redwohly (CA) soils. Canoecreek soils have greater than 35 percent rock fragments in the particle size control section and occur on linear to convex or slightly concave positions. Gibsoncreek soils have between 18 and 24 percent clay in the particle size control section and occur on linear to convex positions. Redwohly soils have bedrock with cracks spaced closer than 10 centimeters apart between 50 and 100 centimeters and are found on strongly convex positions.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; high or very high runoff; moderately high to moderately low saturated hydraulic conductivity.
USE AND VEGETATION: This soil is used for timber production, wildlife habitat, and watershed. Natural vegetation includes Douglas-fir, tanoak, and Pacific madrone, and evergreen huckleberry. When present, coast redwood is less than 50 percent
DISTRIBUTION AND EXTENT: Coastal Redwood Belt; MLRA 4B. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Humboldt County, South Part, California, 2010. The name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
1. Ochric epipedon: The zone from 0 to 15 centimeters (Oi and A horizons)
2. Cambic horizon: The zone from 15 to 200 centimeters (Bt horizons)
3. Particle-size control section: The zone from 29 to 104 centimeters
(Bt1, Bt2 and Bt3 horizons)
4. A cool phase exists where redwoods are present
ADDITIONAL DATA: NSSL Pedon No. 05N0131
NASIS User Pedon ID 04CA601271
Keys to Soil Taxonomy, 11th edition
National Cooperative Soil Survey
U.S.A.