LOCATION SHIVELYFLAT CA
Established Series
REV: JWH/JTB/ET
05/2016
SHIVELYFLAT SERIES
The Shivelyflat series consists of very deep, somewhat poorly drained soils formed in alluvium derived from mixed sedimentary sources. Shivelyflat soils are on flood-plain steps in mountain river valleys. Slope ranges from 0 to 2 percent. Mean annual precipitation is about 1525 mm and the mean annual temperature is about 13 degrees C.
TAXONOMIC CLASS: Fine-silty, mixed, superactive, nonacid, thermic Aquic Udifluvents
TYPICAL PEDON: Shivelyflat loam on an east facing 1 percent slope under a cultivated field at an elevation of 36 meters. (Colors are for moist soil unless otherwise stated.) When described on October 30, 2007 the soil was moist throughout.
Ap1--0 to 20 cm; dark olive brown (2.5Y 3/3) loam, grayish brown (2.5Y 5/2) dry; weak very coarse subangular blocky structure parting to moderate fine granular; moderately hard, friable, slightly sticky and slightly plastic; common very fine, few fine, and common medium roots throughout; few very fine and fine tubular pores; moderately acid (pH 5.9); clear smooth boundary.
Ap2--20 to 43 cm; olive brown (2.5Y 4/3) loam, light brownish gray (2.5Y 6/2) dry; weak medium subangular blocky structure; moderately hard, friable, slightly sticky and slightly plastic; common very fine and few fine roots throughout; few very fine and fine tubular pores; moderately acid (pH 6.0); clear smooth boundary.
Ap3--43 to 78 cm; very dark grayish brown (2.5Y 3/2) silt loam, light brownish gray (2.5Y 6/2) dry; weak medium subangular blocky structure; moderately hard, friable, slightly sticky and slightly plastic; common very fine roots throughout; many very fine and common fine and medium tubular pores; 5 percent medium distinct irregular, gray (10YR 5/1), iron depletions in matrix and 15 percent medium prominent irregular, dark yellowish brown (10YR 4/6), iron-manganese masses in matrix; slightly acid (pH 6.5); clear smooth boundary. (Combined thickness of the A horizons is 10 to 80 centimeters)
C1--78 to 102 cm; 80 percent dark grayish brown (2.5Y 4/2) and 20 percent dark olive brown (2.5Y 3/3) silt loam, light brownish gray (2.5Y 6/2) dry; massive; moderately hard, very friable, slightly sticky and slightly plastic; common fine roots throughout; many very fine and common fine and medium tubular pores; 5 percent medium distinct irregular, gray (10YR 5/1), iron depletions in matrix and 10 percent medium prominent irregular, dark yellowish brown (10YR 4/6), iron-manganese masses in matrix; neutral (pH 6.8); clear smooth boundary.
C2--102 to 138 cm; olive brown (2.5Y 4/3) silt loam, light olive brown (2.5Y 5/3) dry; massive; moderately hard, friable, slightly sticky and slightly plastic; common fine roots throughout; many very fine and common fine, medium, and coarse tubular pores; 5 percent medium distinct irregular, gray (10YR 5/1), iron depletions in matrix and 10 percent medium prominent irregular, dark yellowish brown (10YR 4/6), iron-manganese masses in matrix; neutral (pH 6.8); clear smooth boundary.
C3--138 to 185 cm; olive brown (2.5Y 4/3) silt loam, light olive brown (2.5Y 5/3) dry; massive; moderately hard, friable, slightly sticky and slightly plastic; common fine roots throughout; many very fine, common fine and medium tubular pores; 5 percent medium distinct irregular, gray (10YR 5/1), iron depletions in matrix and 15 percent medium prominent irregular, yellowish brown (10YR 5/6), masses of oxidized iron in matrix; neutral (pH 6.8); clear smooth boundary.
C4--185 to 200 cm; dark grayish brown (2.5Y 4/2) silt loam, grayish brown (2.5Y 5/2) dry; massive; moderately hard, very friable, slightly sticky and slightly plastic; few fine roots throughout; many very fine and common fine tubular pores; 15 percent medium faint irregular, gray (10YR 5/1) iron depletions in matrix and 15 percent medium prominent platy, yellowish brown (10YR 5/6), masses of oxidized iron in matrix; neutral (pH 7.0). (Combined thickness of the C horizons is 150 to 190 centimeters)
TYPE LOCATION: Humboldt County, California; about 1 kilometer northwest of the town of Shively; USGS Quadrangle Redcrest, CA; WGS84 Decimal degrees 40.4368028 latitude and -123.9734000 longitude; UTM Zone 10 417442mE, 4476695mN; NAD 83.
RANGE IN CHARACTERISTICS:
Soil Temperature: The mean annual soil temperature at 50 centimeters is 15 to 16 degrees C and the difference between mean summer and mean winter soil temperatures is 6 degrees C or greater. The soil has a thermic soil temperature regime.
Soil Moisture: The soil moisture control section is not dry in any part for as long as 90 cumulative days in normal years and is dry in all parts for less than 45 consecutive days in the 4 months following the summer solstice. The soil has a udic soil moisture regime.
Depth to Redoximorphic Features: 25 to 50 centimeters
Particle size control section (weighted average):
Rock fragments: 0 to 2 percent gravel
Clay content: 18 to 25 percent
Particles 0.1 millimeters or coarser: less than 15 percent
A horizons:
Hue: 10YR or 2.5Y
Value: 3 or 4, 5 or 6 dry
Chroma: 2 or 3, moist or dry
Clay content: 13 to 20 percent
Rock fragments: 0 to 2 percent gravel
Reaction: moderately acid
Redoximorphic Features: fine and medium iron-manganese masses
Quantity: none to many
Hue: 10YR or 2.5Y
Value: 4 to 6
Chroma: 3 to 8
Redoximorphic features: fine and medium iron depletions
Quantity: none to common
Hue: 2.5Y or 5Y
Value: 4 or 5
Chroma: 1 or 2
C horizons:
Hue: 10YR or 2.5Y
Value: 3 or 4, 5 or 6, dry
Chroma: 2 or 3, moist or dry
Texture: silt loam, very fine sandy loam, fine sandy loam
Clay content: 13 to 25 percent
Rock fragments: 0 to 5 percent gravel
Reaction: Slightly acid to neutral
Redoximorphic features: fine and medium iron-manganese masses
Quantity: few to many
Hue: 10YR or 2.5Y
Value: 4 to 6
Chroma: 3 to 8
Redoximorphic features: fine and medium iron depletions
Quantity: few to common
Hue: 2.5Y or 5Y
Value: 4 or 5
Chroma: 1 or 2
Some pedons have Ab horizons:
Hue: 10YR or 2.5Y
Value: 2 or 3, 4 or 5 dry
Chroma: 1 to 3, moist or dry
Texture: silt loam or very fine sandy loam
Clay content: 10 to 17 percent
Rock fragments: 0 to 2 percent gravel
Reaction: Slightly acid to neutral
Redoximorphic Features: fine and medium iron-manganese masses
Quantity: few to many
Hue: 7.5YR, 10YR, or 2.5Y
Value: 4 to 6
Chroma: 3 to 6
Redoximorphic features: fine and medium iron depletions
Quantity: few to common
Hue: 2.5Y or 5Y
Value: 4 or 5
Chroma: 1 or 2
COMPETING SERIES: There are no competing series in this family.
GEOGRAPHIC SETTING: Shivelyflat soils are on linear to slightly concave positions on flood-plain steps in mountain river valleys. Slopes are 0 to 2 percent. Elevations are 18 to 170 meters. These soils formed in alluvium from mixed sedimentary sources. The climate is humid with cool, foggy summers and cool, wet winters. Mean annual precipitation is 1015 to 1780 millimeters. The mean annual temperature is 12 to 14 degrees C. Frost free season is about 300 to 350 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Cottoneva (CA),
Eelriver (CA), and
Pepperwood (CA) soils. Cottoneva and Eelriver occur are under native redwood forest where the difference between mean summer and mean winter soil temperatures is less than 6 degrees C. Cottoneva and Pepperwood soils have greater than 15 percent particles 0.1 mm or coarser. Cottoneva and Pepperwood soils occur on linear to slightly convex positions on floodplain steps and natural levees. Eelriver soils occur on the same positions as Shivelyflat soils.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat poorly drained; very high runoff; moderately high saturated hydraulic conductivity. The soils are rarely flooded for very brief periods December through February. The soils frequently have 1 to 3 cm of ponding for very brief periods December through March.
USE AND VEGETATION: This soil is used mainly for pasture and hay with small areas used for orchards, vineyards, and non-irrigated truck crops. Uncultivated vegetation includes wild oat, soft chess, ripgut brome, medusahead, dogtail grass, pennyroyal, and various other forbs. These soils once supported redwood.
DISTRIBUTION AND EXTENT: Coastal Redwood Belt, MLRA 4B. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Humboldt County, South Part. California, 2010. The name is from Shively Flat.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
1. Ochric epipedon: The zone from 0 to 78 centimeters. (Ap horizons)
2. Particle size control section: The zone from 25 to 100 centimeters averages 19 percent clay and 12 percent fine sand or coarser. (Ap2, Ap3, C1 horizons)
3. Aquic feature: The zone from 43 to 200 centimeters (Ap2, Ap3, C1, C2, C3, C4 horizons)
The series type location was moved in 2009 to better reflect the series concepts.
ADDITIONAL DATA: NSSL Pedon No. 08N0234 and selected horizons from 07N0354 and 07N0356 are correlated to this series. NASIS User Pedon ID: 07CA601932
Keys to Soil Taxonomy, 12th edition.
National Cooperative Soil Survey
U.S.A.