LOCATION EASTBIGGS CAEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, thermic Abruptic Durixeralfs
TYPICAL PEDON: Eastbiggs loam, on a west facing 2 percent slope under a cover of annual grasses and forbs at an elevation of 90 feet, (27 m). When described on 5/11/1992 the soil was dry to 4 inches (10 cm) and slightly moist below. (Colors are for dry soil unless otherwise noted).
A1--0 to 3 inches, (0 to 8 cm); strong brown (7.5YR 4/6) loam, dark brown (7.5YR 3/4) moist; 23 percent clay; weak fine subangular blocky structure; hard, friable, slightly sticky, slightly plastic; many very fine roots; few fine and many very fine tubular pores; 10 percent fine black (N 2/0) moist, iron-manganese nodules; neutral, pH 7.0 by Hellige-Truog; clear smooth boundary.
A2--3 to 10 inches, (8 to 25 cm); strong brown (7.5YR 4/6) loam, dark brown (7.5YR 3/4) moist; 23 percent clay; weak fine subangular blocky structure; hard, friable, slightly sticky, slightly plastic; common very fine roots; few fine and many very fine tubular pores; 10 percent fine black (N 2/0) moist, manganese masses; neutral, pH 7.0 by Hellige-Truog; clear smooth boundary. (Combined thickness of the A horizon is 3 to 16 inches, (8 to 41 cm) thick)
BAt--10 to 17 inches, (25 to 43 cm); strong brown (7.5YR 4/6) loam, dark brown (7.5YR 3/4) moist; 26 percent clay; weak fine subangular blocky structure; hard, friable, slightly sticky, slightly plastic; common very fine roots; few fine and many very fine tubular pores; 10 percent fine black (N 2/0) moist, iron-manganese nodules and 15 percent fine black (N 2/0) moist, manganese masses; neutral, pH 7.0 by Hellige-Truog; abrupt smooth boundary. (6 to 17 inches, (15 to 43 cm) thick)
2Bt--17 to 27 inches, (43 to 69 cm); brown (7.5YR 5/4) clay, brown (7.5YR 4/4) moist; 50 percent clay; strong coarse prismatic structure; very hard, firm, very sticky, very plastic; common very fine roots; common very fine tubular pores; 2 percent pressure faces; 10 percent fine black (N 2/0) moist, iron-manganese nodules and 15 percent fine black (N 2/0) moist, manganese masses; neutral, pH 7.0 by Hellige-Truog; abrupt smooth boundary. (7 to 30 inches, (18 to 76 cm) thick)
3Bqm1--27 to 34 inches, (69 to 86 cm); duripan with indurated laminar capping 1/4 to 1/2 inch,(6 to 12 mm) thick; strong fine platy structure; very rigid, indurated, cemented by silica; roots matted on top of capping; 1/8 inch, (3 mm) thick black (N 2/0) moist, manganese coatings on top of laminar capping; abrupt smooth boundary.
3Bqm2--34 to 60 inches, (86 to 152 cm); duripan; rigid, strongly cemented by silica.
TYPE LOCATION: Butte County, California, about 1.4 miles west of Honcut, approximately 1450 feet west and 1500 feet south of the northeast corner of Section 18, Township 17 N., Range 4 E., 39 degrees, 19 minutes, 55 seconds North latitude and 121 degrees, 33 minutes, 43 seconds West longitude, NAD27 - U.S.G.S Quad: Honcut, California.
RANGE IN CHARACTERISTICS: Depth to duripan is 20 to 40 inches, (51 to 102 cm). The mean annual soil temperature is 60 to 64 degrees F, (16 to 18 degrees C). The soil moisture control section is dry from June to November (170 to 190 days). The particle-size control section averages 35 to 50 percent clay. There is an abrupt boundary at the top of the argillic horizon with an absolute clay increase of at least 15 percent. Mineralogy is mixed. Redoximorphic features such as manganese nodules, manganese masses with colors of N 2/0 moist, and oxidized iron masses with colors of 7.5YR 4/6 or 5/6 moist, occur from 3 to 34 inches, (8 to 86 cm). A fluctuating water table can occur between the top of the duripan and 14 inches, (36 cm) below the surface of the soil from December through April. Some pedons have lime in the 2Bt horizon.
The A horizon dry color is 7.5YR 4/4, 4/6, 5/4, 6/2, 10YR 5/4, 6/2, 6/3 or 6/4. Moist color is 7.5YR 3/4, 4/4, 10YR 3/2, 3/3 or 3/4. Texture is loam or fine sandy loam. Clay content ranges from 15 to 27 percent. Organic matter ranges from 0.2 to 1 percent. Reaction ranges from moderately acid to neutral.
The BAt, Bt or Btb horizon dry color is 7.5YR 4/6, 5/3, 6/3 or 10YR 5/4. Moist color is 7.5YR 3/4, 4/3, 5/3, 10YR 4/3 or 5YR 4/4. Texture is loam, clay loam or sandy clay loam. Clay content ranges from 20 to 35 percent. Organic matter ranges from 0.1 to 0.5 percent. Reaction ranges from slightly acid to neutral.
The 2Bt horizon dry color is 7.5YR 4/4, 5/4, 5/6 or 6/4. Moist color is 7.5YR 4/3, 4/4 or 5YR 4/6. Texture is clay. Clay content ranges from 40 to 50 percent. Organic matter ranges from 0.1 to 0.3 percent. Reaction is neutral.
COMPETING SERIES: These are the Redding, San Joaquin and Yuvas soils. Redding soils lack a water table, have gravel throughout, and are on mounds on high terraces. San Joaquin soils lack a water table, are formed from alluvium from dominantly granitic sources and are on low terraces. Yuvas soils have siltstone (densic material) underlying the duripan and are on remnant terraces and basin rims.
GEOGRAPHIC SETTING: Eastbiggs soils are on mounds on low terraces. Slopes range from 0 to 3 percent. These soils formed in alluvium from igneous and metamorphic rocks. Elevation is 70 to 140 feet, (21 to 43 m). The mean annual precipitation is 19 to 23 inches, (483 to 584 mm). The mean annual temperature is 61 degrees F, (16 degrees C). Frost free season is 240 to 250 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Boga, Esquon, Galt, Kimball, Loemstone, Neerdobe, and Wilsoncreek soils. The Boga soils are fine loamy, very deep to densic material and are on low terraces. Esquon soils are fine, deep to duripan and are on basin floors. Galt soils are fine, moderately deep to duripan and are in small basins on low terraces. Kimball soils are very deep, fine and are on slightly higher positions on low terraces. Neerdobe soils are fine, moderately deep to duripan and are on basin floors. Wilsoncreek soils are very deep, fine-silty and are on stream terraces.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; high to very high runoff; moderate saturated hydraulic conductivity in the A and BAt horizons, slow to moderately slow in the 2Bt horizon and is impermeable in the 3Bqm horizon. A fluctuating water table can occur between the top of the duripan and 14 inches, (36 cm) below the surface of the soil from December through April.
USE AND VEGETATION: This soil is used for livestock grazing, rice production and wildlife habitat. Vegetation is wild oat, vetch, filaree, soft chess, ripgut brome, red brome, Mediterranean barley, clover, butter n eggs and wild onion.
DISTRIBUTION AND EXTENT: Butte County, California. MLRA 17 - Sacramento Valley. The soils are inextensive and are mapped in Butte County,
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Butte County, California, 2005. Source of name from town of East Biggs.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Ochric Epipedon 0 to 10 inches, (0 to 25 cm)
Abrupt Textural Change 17 to 27 inches, (43 to 69 cm)
Argillic Horizon 17 to 27 inches, (43 to 69cm)
Duripan 27 to 34 inches, (69 to 86 cm)
The soil moisture control section - zone from 6 to 10 inches, (15 to 25 cm).
The particle-size control section - zone from 17 to 27 inches (43 to 69 cm).