LOCATION NEERDOBE CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Xeric Duraquerts
TYPICAL PEDON: Neerdobe clay on a less than 1 percent slope under a cover of rice at an elevation of 98 feet, (30 m). When described on 5/3/1995, the soil was moist throughout. A water table was at a depth of 38 inches, (97 cm). (Colors are for dry soil unless otherwise stated.
Ap--0 to 5 inches, (0 to 13 cm); dark gray (10YR 4/1) clay, dark gray (10YR 4/1) moist; 57 percent clay; moderate medium subangular blocky structure parting to strong fine granular; extremely hard, very firm, moderately sticky and very plastic; few very fine roots and common fine roots; few fine irregular pores; noneffervescent; moderately acid, pH 5.8 by pH meter 1:1 water; abrupt smooth boundary. (3 to 13 inches, (8 to 33 cm) thick)
Bssg1--5 to 15 inches, (13 to 38 cm); dark gray (10YR 4/1) clay, dark gray (10YR 4/1) moist; 55 percent clay; moderate medium prismatic structure parting to moderate fine angular blocky; extremely hard, very firm, moderately sticky and very plastic; few very fine roots; few very fine tubular pores; continuous slickensides; common fine irregular strong brown (7.5YR 4/6), oxidized iron masses and common fine and coarse threadlike gray (10YR 6/1) iron depletions; noneffervescent; slightly alkaline, pH 7.4 by pH meter 1:1 water; clear smooth boundary.
Bssg2--15 to 23 inches, (38 to 58 cm); dark gray (10YR 4/1) clay, dark gray (10YR 4/1) moist; 56 percent clay; moderate medium prismatic structure parting to moderate fine angular blocky; extremely hard, very firm, moderately sticky and very plastic; few very fine roots; few very fine tubular pores; many slickensides; common fine irregular strong brown (7.5YR 4/6) oxidized iron masses and common fine threadlike gray (10YR 6/1) iron depletions; noneffervescent; moderately alkaline, pH 7.9 by pH meter 1:1 water; clear smooth boundary.
Bssg3--23 to 28 inches, (58 to 71 cm); dark grayish brown (10YR 4/2) clay, dark gray (10YR 4/1) moist; 56 percent clay; moderate medium angular blocky structure; extremely hard, very firm, moderately sticky and very plastic; few very fine roots; few very fine tubular pores; common slickensides; common fine and medium spherical carbonate concretions; common fine irregular gray (10YR 6/1) iron depletions, and few fine spherical gray (N 5/0)dry, iron depletions; noneffervescent; moderately alkaline, pH 8.2 by pH meter 1:1 water; abrupt smooth boundary. (Combined thickness of the Bssg horizon is 12 to 25 inches, (30 to 63 cm) thick).
Bk--28 to 33 inches, (71 to 84 cm); light brownish gray (10YR 6/2) clay grayish brown (10YR 5/2) moist; 55 percent clay; moderate fine angular blocky structure parting to strong fine angular blocky; slightly hard, friable, moderately sticky and very plastic; common very fine tubular pores and few fine tubular pores; common fine irregular carbonate concretions and common fine irregular carbonate masses; common fine threadlike gray (10YR 6/1) iron depletions; strongly effervescent; strongly alkaline, pH 8.5 by pH meter 1:1 water; abrupt smooth boundary. (4 to 8 inches, (10 to 20 cm) thick)
2Bkq--33 to 38 inches, (84 to 97 cm); very pale brown (10YR 7/3) loam, brown (10YR 5/3) moist; 22 percent clay; strong fine platy structure; slightly hard, friable, weakly cemented, slightly sticky and slightly plastic; common fine tubular pores and few very fine tubular pores; common fine threadlike gray (10YR 6/1), dry, iron depletions between peds; strongly effervescent; strongly alkaline, pH 8.6 by pH meter 1:1 water; abrupt smooth boundary. (0 to 7 inches, (0 to 18 cm) thick).
2Bkqm--38 to 56 inches, (97 to 142 cm); indurated duripan; very pale brown (10YR 7/3) loam, brown (10YR 4/3) moist; 18 percent clay; strong fine platy structure; indurated, masses of silica; slightly effervescent; strongly alkaline, pH 8.6 by pH meter 1:1 water. Alternating layers of indurated and moderately cemented from 38 to 56 inches (97 to 142 cm.). Silica and lime threads throughout the duripan.
TYPE LOCATION: Butte County, California; about 3 miles southwest of Nelson, approximately 2200 feet east and 1900 feet north of the southwest corner of Section 7, Township 19 N., Range 2 E., 39 degrees, 30 minutes, 48 seconds North latitude and 121 degrees, 47 minutes, 30 seconds West longitude, NAD27. - U.S.G.S. Quad: Nelson, California.
RANGE IN CHARACTERISTICS: Depth to duripan is 20 to 40 inches, (51 to 102 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 40 to 60 percent clay. Base saturation by ammonium acetate ranges from 90 to 100 percent throughout. Depth to carbonates ranges from 15 to 38 inches, (38 to 97 cm). SAR ranges from 0 to 2 throughout. Exchangeable sodium ranges from 1 to 4 percent throughout. Electrical conductivity ranges from 0 to 1 mmho/cm throughout. Reversible surface initiated cracks, 1 to 3 inches, (2.54 to 8 cm) wide, extend to a depth of 20 to 36 inches, (51 to 91 cm) from May 15 to October 15 (150 days) when not irrigated. Common to many slickensides are in the Bssg horizon. A fluctuating water table can occur from the top of the duripan to the surface of the soil from December through May. Redoximorphic features such as manganese masses with colors of N 2/0 and oxidized iron masses with colors of 7.5YR 4/4 and matrix chromas of 2 or less occur in horizons above the duripan. Some pedons have few to common manganese nodules. Some pedons have silt loam overwash from 6 to 20 inches, (15 to 51 cm) thick and may have stratified layers of silt loam, very fine sandy loam, loamy very fine sand, sandy loam, fine sandy loam, or loam with 2 to 25 percent clay. Some pedons lack calcium carbonate.
The Ap horizon dry color is 10YR 3/1, 4/1, 4/2 or 5/2. Moist color is 10YR 3/1 4/1 or 3/2. Texture is clay or clay loam. Clay content ranges from 35 to 60 percent. Organic matter ranges from 1 to 2.5 percent. Rock fragments, range from 0 to 2 percent gravel. Reaction ranges from moderately acid to neutral.
The Bssg horizon dry color is 10YR 3/1, 4/1, 4/2 or 5/2. Moist color is 10YR 3/1, 3/2, 4/1 or 4/2. Texture is silty clay or clay. Clay content ranges from 40 to 60 percent. Organic matter ranges from 0.5 to 1 percent. Reaction ranges from slightly alkaline to moderately alkaline.
The Bk horizon dry color is 10YR 4/1, 4/2, 5/1, 5/2 or 5/3. Moist color is 10YR 3/1, 3/2, 3/3, 4/2 or 4/3. Texture is clay or clay loam. Clay content ranges from 35 to 60 percent. Organic matter ranges from 0.1 to 0.5 percent. Effervescence ranges from slight to strong. Reaction ranges from moderately alkaline to strongly alkaline.
The 2Bkq horizon dry color is 10YR 7/3 or 8/3. Moist color is 10YR 4/3 or 5/3. Texture is loam. Clay content ranges from 18 to 27 percent. It is moderately to strongly cemented with silica and lime. Effervescence ranges from moderate to strong.
The 2Bkqm horizon dry color is 10YR 4/3, 5/3, 6/3, 7/3, or 8/3. Moist color is 10YR 3/3, 4/3, 5/3 or 7.5YR 4/4. It is weakly cemented to indurated with silica. Effervescence ranges from slight to violent.
COMPETING SERIES: These are the Jacktone and Ordferry series. Jacktone soils are somewhat poorly drained and have a water table below 5 feet, (152 cm). Ordferry soils have chromic colors.
GEOGRAPHIC SETTING: Neerdobe soils are in flood basins. Slopes range from 0 to 1 percent. These soils formed in alluvium from mixed rocks. Elevation is 55 to 170 feet, (17 to 52 m). The mean annual precipitation is 18 to 25 inches, (457 to 635 mm). The mean annual temperature is 59 to 62 degrees F, (15 to 17 degrees C). Frost free season is 240 to 250 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Blavo, Esquon, Eastbiggs and Lofgren. Blavo soils are moderately deep to a duripan and are very-fine. Esquon soils are deep to a duripan. Eastbiggs soils are moderately deep to a duripan, have an argillic horizon with an abrupt clay increase and are on low terraces. Lofgren soils are deep to a duripan and are very-fine.
DRAINAGE AND PERMEABILITY: Poorly drained; high to very high runoff; slow saturated hydraulic conductivity in the Ap and the Bssg horizons, moderately slow to slow in the Bk horizon, moderate in the 2Bkq 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. Water frequently ponds up to 6 inches, (15 cm) above the surface for long duration from December through March.
USE AND VEGETATION: This soil is used for production of rice and wildlife habitat. The natural vegetation is grasses and hydrophytic plants.
DISTRIBUTION AND EXTENT: Butte County, California. MLRA 17 Sacramento Valley. The soils are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Butte County, California, 2005. Source of name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon 0 to 15 inches, (0 to 38 cm) (Ap, Bssg1).
Cambic horizon 15 to 33 inches, (38 to 84 cm) (Bssg2, Bssg3, Bk).
Duripan 38 to 60 inches, (97 to 152 cm) (2Bkqm).
Lithologic discontinuity 44 to 82 inches, (112 to 208 cm) (2Bkq, 2Bkqm1, 2Bkqm2).
Redoximorphic features 0 to 60 inches, (0 to 152 cm) (Ap, Bssg1, Bssg2, Bssg3, Bk, 2Bkq, 2Bkqm).
Particle-size control section 10 to 38 inches, (25 to 97 cm).
Soil moisture control section 7 to 21 inches, (18 to 53 cm).
This soil was previously mapped as Stockton brown phase in the Soil Survey of the Oroville Area, California 1926 and the Soil Survey of the Chico Area, California 1925.
ADDITIONAL DATA: Characterization data from lab pedon number: 95P0512, NSSL, Lincoln, NE.