LOCATION ESQUON CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Xeric Epiaquerts
TYPICAL PEDON: Esquon clay, on a less than 1 percent slope, under a cover of rice at an elevation of 107 feet, (33 m). When described on 5/3/1995, the soil was moist throughout. (Colors are for dry soil unless otherwise noted).
Ap--0 to 5 inches, (0 to 13 cm); dark grayish brown (10YR 4/2) clay, dark gray (10YR 4/1) moist; 47 percent clay; moderate medium subangular blocky structure parting to weak fine granular; extremely hard, firm, very sticky and very plastic; common very fine and fine roots; many fine irregular pores; common fine irregular brown (7.5YR 4/4) moist, oxidized iron masses; noneffervescent; very strongly acid, pH 4.5 by pH meter 1:1 water; abrupt smooth boundary. (4 to 10 inches, (10 to 25 cm) thick).
Bssg--5 to 11 inches, (13 to 28 cm); dark grayish brown (10YR 4/2) clay, dark gray (10YR 4/1) moist; 45 percent clay; moderate medium prismatic structure parting to weak fine angular blocky; extremely hard, firm, very sticky and very plastic; few very fine and fine roots; few very fine tubular pores; few slickensides; many fine irregular dark brown (7.5YR 3/4)moist, oxidized iron masses, common fine irregular black (2/0) moist, manganese masses and common fine spherical black (N 2/0) moist, iron-manganese concretions; noneffervescent; slightly acid, pH 6.2 by pH meter 1:1 water; abrupt smooth boundary. (5 to 40 inches, 13 to 102 cm) thick).
Bss1--11 to 22 inches, (28 to 56 cm); dark grayish brown (10YR 4/2) clay, dark grayish brown (10YR 4/2) moist; 44 percent clay; moderate coarse prismatic structure parting to moderate fine angular blocky; extremely hard, firm, very sticky and very plastic; few very fine roots; few very fine tubular pores; few slickensides ; common fine irregular dark gray (10YR 4/1) moist, iron depletions, many fine irregular brown (10YR 4/3) moist, oxidized iron masses, common fine irregular brown (7.5YR 4/4) moist, oxidized iron masses and common fine spherical black (N 2/0) moist, manganese masses; noneffervescent; 1 percent subrounded gravel; neutral, pH 7.3 by pH meter 1:1 water; gradual smooth boundary.
Bss2--22 to 35 inches, (56 to 89 cm); brown (10YR 4/3) clay, dark grayish brown (10YR 4/2) moist; 44 percent clay; moderate medium prismatic structure parting to weak fine angular blocky; extremely hard, very firm, very sticky and very plastic; few very fine roots; common very fine tubular pores; few slickensides; common fine threadlike dark gray (10YR 4/1) moist, iron depletions and few fine spherical black (N 2/0) moist, iron-manganese nodules; noneffervescent; 1 percent subrounded gravel; slightly alkaline, pH 7.5 by pH meter 1:1 water; gradual smooth boundary. (Combined thickness of the Bss horizon is 20 to 40 inches, (51 to 102 cm) thick).
Bkss1--35 to 46 inches, (89 to 117 cm); brown (10YR 5/3) clay, brown (10YR 4/3) moist; 41 percent clay; weak fine prismatic structure parting to weak fine angular blocky; very hard, firm, very sticky and very plastic; common very fine tubular pores; few slickensides; common fine thread like gray (10YR 5/1) moist, iron depletions; carbonates, finely disseminated; slightly effervescent; 1 percent subrounded gravel; slightly alkaline, pH 7.7 by pH meter 1:1 water; clear smooth boundary.
Bkss2--46 to 50 inches, (117 to 127 cm); brown (10YR 5/3) silty clay, brown (10YR 4/3) moist; 42 percent clay; weak fine angular blocky structure; very hard, firm, very sticky and very plastic; common very fine and few fine tubular pores; few slickensides; few fine spherical black (N 2/0) moist, iron-manganese concretions; carbonates, finely disseminated; slightly effervescent; slightly alkaline, pH 7.7 by pH meter 1:1 water; abrupt smooth boundary. (Combined thickness of the Bkss horizon is 12 to 25 inches, 30 to 63 cm) thick.)
Bk--50 to 56 inches, (127 to 142 cm); light yellowish brown(10YR 6/4) clay loam, brown (10YR 4/3) moist; 25 percent clay; weak fine subangular blocky structure; rigid, moderately sticky and moderately plastic; common very fine tubular pores; few fine spherical black (N2/0) moist, iron-manganese concretions; common fine threadlike carbonate masses; slightly effervescent; slightly alkaline, pH 7.7 by pH meter 1:1 water; abrupt smooth boundary. (5 to 10 inches, (13 to 25 cm) thick).
2Bkqm--56 to 67 inches, (142 to 170 cm); moderately cemented duripan; very pale brown (10YR 7/4) loam, brown (10YR 4/3) moist; 18 percent clay; massive; rigid, moderately cemented, nonsticky and slightly plastic; common very fine tubular pores; common fine threadlike carbonate masses; strongly effervescent; 5 percent subrounded gravel; moderately alkaline, pH 8.1 by pH meter 1:1 water; 1/32 inch, (1 mm) platy silica capping on duripan. (10 to 30 inches, 25 to 76 cm) or more thick).
TYPE LOCATION: Butte County, California; about 1.4 miles east of Richvale, approximately 2150 feet east and 100 feet south of the northwest corner of Section 23, Township 19 N., Range 2 E., 39 degrees, 29 minutes, 36 seconds North latitude and 121 degrees, 43 minutes, 4 seconds West longitude, NAD27. - U.S.G.S. Quad: Biggs, California.
RANGE IN CHARACTERISTICS: Depth to duripan is 40 to 60 inches, (102 to 152 cm). The mean annual soil temperature is 62 to 66 degrees F, (17 to 19 degrees C). The soil moisture control section is dry from June to October (120 to 125 days). The particle-size control section averages 50 to 55 percent clay. Base saturation by ammonium acetate ranges from 90 to 100 percent throughout. Reversible surface-initiated cracks 1 to 2 inches, (2.54 to 5 cm) wide extend to a depth of 30 to 35 inches, (76 to 89 cm) from May 15 to October 15 (150 days) when not irrigated. Depth to calcium carbonate ranges from 20 to 60 inches, (51 to 152 cm) and ranges from no reaction to strongly effervescent. Electrical conductivity is less than 1 mmho/cm throughout. Common to many slickensides are in the Bssg, Bss and Bkss horizons at 5 to 50 inches, (13 to 127 cm). A fluctuating water table can occur between the top of the duripan and the surface of the soil from December through May. In some areas a fluctuating water table can occur between the top of the duripan and surface of the soil from November through June and from the top of the duripan and 36 inches, (91 cm) below the surface of the soil from July through October. Redoximorphic features such as manganese nodules, oxidized iron masses with colors of 7.5YR 4/6 moist, manganese masses with colors of N 2/0 moist, iron depletions with colors of 10YR 4/1 or 5/1 moist and reduced matrix with chromas of 2 or less occur in horizons above the duripan. Some pedons have silt loam, silty clay loam or stratified very fine sandy loam to silt loam overwash that ranges from 6 to 12 inches, (15 to 51 cm) thick and clay content ranges from 12 to 40 percent.
The Ap or Ab horizon dry color is 10YR 3/1, 4/1, 4/2, 5/1 or 5/2. Moist color is 10YR 3/1 or 3/2. Texture is clay or silty clay. Clay content ranges from 40 to 60 percent. Organic matter ranges from 1 to 2.5 percent. Reaction ranges from very strongly acid to neutral.
The Bssg and Bss horizon dry color is 10YR 4/1, 4/2 or 5/2. Moist color is 10YR 3/1 or 3/2. Texture is silty clay or clay. Clay content ranges from 40 to 60 percent. Organic matter ranges from 0.4 to 1 percent. Rock fragments range from 0 to 2 percent gravel. Reaction ranges from slightly acid to moderately alkaline.
The Bkss horizon dry color is 10YR 5/3 or 6/3. Moist color is 10YR 3/3 or 4/3. Texture is silty clay or clay. Clay content ranges from 40 to 60 percent. Organic matter ranges from 0.1 to 0.5 percent. Rock fragments range from 0 to 2 percent gravel. Reaction ranges from neutral to moderately alkaline.
The Bk horizon dry color is 10YR 5/3 or 4/3. Moist color is 10YR 3/3 or 4/3. Texture is silty clay, clay loam or silty clay loam. Clay content ranges from 25 to 60 percent. Organic matter ranges from 0.1 to 0.5 percent. Reaction ranges from slightly alkaline to moderately alkaline.
The 2Bkqm horizon dry color is 10YR 5/3 or 4/3. Moist color is 10YR 4/3. Rupture resistance ranges from indurated to strongly cemented with alternating weak and moderately cemented layers cemented with silica and lime. Reaction is moderately alkaline.
COMPETING SERIES: These are the Edjobe, Subaco and Stockton series. Edjobe soils have a duripan at depths of 60 to 80 inches, (152 to 203 cm). Subaco soils have a paralithic contact at 20 to 40 inches, (51 to 102 cm). Stockton soils are somewhat poorly drained, lack iron depletions and do not have a water table.
GEOGRAPHIC SETTING: Esquon soils are in flood basins. Slopes range from 0 to 1 percent. These soils formed in alluvium from mixed rocks. Elevation is 50 to 150 feet, (15 to 46 m). The mean annual precipitation is 16 to 20 inches, (406 to 508 mm). The mean annual air temperature is 60 to 64 degrees F, (16 to 18 degrees C). The mean January temperature is about 46 degrees F, (8 degrees C). The mean July temperature is about 79 degrees F, (26 degrees C). Frost free season is 240 to 260 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Blavo, Eastbiggs, Edjobe, Lofgren and Neerdobe series. Blavo soils are moderately deep to a duripan and are very fine. Eastbiggs soils are moderately deep to a duripan and have an argillic horizon with an abrupt clay increase and are on low terraces. Edjobe soils are very deep to duripan. Lofgren soils are deep to a duripan and are very fine. Neerdobe soils are moderately deep to a duripan.
DRAINAGE AND PERMEABILITY: Poorly drained; high runoff; slow saturated hydraulic conductivity in the Ap, Bssg, Bss and Bkss horizons, moderate to moderately slow in the Bk horizon and impermeable in the 2Bkqm horizon. A fluctuating water table can occur between the top of the duripan and the surface of the soil from December through May. In some areas a fluctuating water table can occur between the top of the duripan and surface of the soil from November through June and from the top of the duripan and 36 inches, (91 cm) below the surface of the soil from July through October. Water frequently ponds up to 6 inches, (15 cm) above the surface for long duration from December through March. Dams, levees, drainage ditches and leveling for agriculture have altered the frequency and duration of saturation, ponding and flooding.
USE AND VEGETATION: This soil is used for rice production and wetland wildlife habitat. The natural vegetation is grasses and hydrophytic plants.
DISTRIBUTION AND EXTENT: Butte and Sutter Counties, California. MLRA 17 - Sacramento Valley. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Butte County, California, 2005. Source of name is from the Esquon Land Grant.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon 0 to 5 inches, (0 to 13 cm) (Ap)
Cambic horizon 5 to 56 inches, (13 to 142 cm) (Bssg, Bss1, Bss2, Bkss1, Bkss2 Bk)
Duripan 56 to 67 inches, (142 to 170 cm) (2Bkqm)
Lithologic discontinuity (30 to 60 inches) (762 to 152cm) (2Bkqm)
Redoximorphic features 0 to 56 inches, (0 to 142 cm) (Ap, Bssg, Bss1, Bss2 Bkss1, Bkss2, Bk).
The soil moisture control section 7 to 21 inches, (18 to 53 cm).
Particle-size control section 10 to 40 inches, (25 to 102 cm).
Depth to calcium carbonate is variable and reaction varies from no reaction to strongly effervescent. This variability is attributed to specific farm management and or undulating depth to duripan. Leveling and water management also influence the amount of carbonates in the soil.
This soil was previously mapped as Stockton brown phase in the Soil Survey of the Oroville, California, 1926, and the Soil Survey of the Chico Area, California, 1925.
ADDITIONAL DATA: Grab samples were sent to U.C. Davis in 1992 (Lab No.1760). Sample number is Biggs #53. Characterization data from lab pedon number: 95P0511, NSSL, Lincoln, NE.