LOCATION GIANELLA CAEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, nonacid, thermic Typic Xerofluvents
TYPICAL PEDON: Gianella silt loam on a less than one percent slope in a walnut orchard at an elevation of 160 feet, (49 m). When described on 10/27/1988, the soil was moist throughout (irrigated); water table was deeper than 80 inches, (203 cm). (Colors are for dry soil unless otherwise noted).
A--0 to 2 inches, (0 to 5 cm); pale brown (10YR 6/3) silt loam, dark grayish brown (10YR 4/2) moist; 11 percent clay; weak coarse platy structure; slightly hard, very friable, slightly sticky, slightly plastic; few very fine roots; few very fine tubular and common very fine irregular pores; slightly acid, pH 6.6 by pH meter 1:1 water; abrupt smooth boundary. (2 to 8 inches, (5 to 20 cm) thick).
C1--2 to 8 inches, (5 to 20 cm); grayish brown (10YR 5/2) loamy fine sand, very dark grayish brown (10YR 3/2) moist; 4 percent clay; single grain; loose, nonsticky, nonplastic; few very fine roots; common very fine interstitial and few very fine tubular pores; slightly acid, pH 6.6 by pH meter 1:1 water; clear smooth boundary.
C2--8 to 15 inches, (20 to 38 cm); light yellowish brown (10YR 6/4) fine sandy loam, dark brown (10YR 3/3) moist; 8 percent clay; single grain; soft, very friable, slightly sticky, nonplastic; few medium roots; common very fine interstitial and few very fine tubular pores; neutral, pH 6.7 by pH meter 1:1 water; abrupt smooth boundary.
C3--15 to 22 inches, (38 to 56 cm); light yellowish brown (10YR 6/4) very fine sandy loam, dark yellowish brown (10YR 3/4) moist; 6 percent clay; single grain; soft, very friable, nonsticky, nonplastic; few medium roots; common very fine interstitial and few very fine tubular pores; neutral, pH 6.7 by pH meter 1:1 water; clear smooth boundary.
C4--22 to 31 inches, (56 to 79 cm); light brownish gray (2.5Y 6/2) very fine sandy loam, dark grayish brown (2.5Y 4/2) moist; 5 percent clay; single grain; soft, very friable, nonsticky, nonplastic; few medium roots; common very fine interstitial and few very fine tubular pores; neutral, pH 6.8 by pH meter 1:1 water; clear smooth boundary.
C5--31 to 41 inches, (79 to 104 cm); pale brown (10YR 6/3) very fine sandy loam, brown (10YR 4/3) moist; 8 percent clay; single grain; soft, very friable, slightly sticky, slightly plastic; few medium and coarse roots; common very fine tubular pores; 2 percent fine faint very dark brown (10YR 2/2) moist, and grayish brown (10YR 5/2) dry, iron depletions; slightly acid, pH 6.6 by pH meter 1:1 water; clear smooth boundary.
C6--41 to 50 inches, (104 to 127 cm); brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; 14 percent clay; massive; slightly hard, very friable, slightly sticky, slightly plastic; few fine and medium roots; common fine and medium tubular pores; 25 percent worm casts; neutral, pH 6.7 by pH meter 1:1 water; clear smooth boundary.
C7--50 to 54 inches, (127 to 137 cm); pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; 14 percent clay; massive; slightly hard, very friable, slightly sticky, slightly plastic; few fine roots; common very fine and fine tubular pores; neutral, pH 6.8 by pH meter 1:1 water; clear smooth boundary.
C8--54 to 64 inches, (137 to 163 cm); light yellowish brown (10YR 6/4) silt loam, brown (10YR 4/3) moist; 13 percent clay; massive; slightly hard, very friable, slightly sticky, slightly plastic; common fine and medium tubular pores; 1 percent fine prominent strong brown (7.5YR 5/6) moist, oxidized iron masses and 4 percent coarse distinct very dark gray (10YR 3/1) moist, iron depletions; neutral, pH 6.9 by pH meter 1:1 water; abrupt smooth boundary.
C9--64 to 66 inches, (163 to 168 cm); light brownish gray (10YR 6/2) silt loam, brown (10YR 4/3) moist; 12 percent clay; massive; slightly hard, very friable, slightly sticky, slightly plastic; common fine tubular pores; neutral, pH 6.8 by pH meter 1:1 water; abrupt smooth boundary.
C10--66 to 69 inches, (168 to 174 cm); light yellowish brown (10YR 6/4) loam, yellowish brown (10YR 5/4) moist; 10 percent clay; massive; slightly hard, very friable, slightly sticky, slightly plastic; common very fine and fine tubular pores; neutral, pH 7.1 by pH meter 1:1 water; abrupt smooth boundary.
C11--69 to 83 inches, (174 to 210 cm); pale brown (10YR 6/3) loamy fine sand, brown (10YR 4/3) moist; 5 percent clay; single grain; loose, nonsticky, nonplastic; many very fine and fine interstitial pores; neutral, pH 7.1 by pH meter 1:1 water. (Combined thickness of the C horizon is 70 to 80 inches, (178 to 203 cm) or more thick).
TYPE LOCATION: Butte County, California; about 5.7 miles northwest of Nord, on Snaden Island, approximately 2700 feet west and 400 feet south of the west end of Bennett Road; Township 23 N., Range 2 W.; in an unsectionized area in the Bosquejo Land Grant; 39 degrees, 48 minutes, 13 seconds North latitude and 122 degrees, 3 minutes, 19 seconds West longitude, NAD27 - U.S.G.S Quad: Foster Island, California.
RANGE IN CHARACTERISTICS: The Gianella soils are very deep and stratified. The mean annual soil temperature is 60 to 62 degrees F, (16 to 17 degrees C). The particle-size control section averages 10 to 18 percent clay, and has greater than 15 percent fine sand or coarser. Mineralogy is mixed. This soil is noncalcareous throughout. Organic matter decreases irregularly with depth, and ranges from 4.0 at the surface to 0.34 percent to a depth of 83 inches, (211 cm). A fluctuating water table can occur at depths of 33 to over 80 inches, (83 to 203 cm) below the surface of the soil from December through March. Redoximorphic features such soft oxidized iron masses with colors of 7.5YR 4/4 or 4/6 moist, may be present at a depth as high as 18 inches, (46 cm). Redoxomorphic features may be present in the A horizon, especially if the horizon has platy structure. Gravel on the surface ranges from 0 to 20 percent. Some pedons have Ab horizons commonly with textures of silt loam or loam. Some pedons have gravelly substratums.
The A and Ap horizons dry color is 10YR 5/3, 6/3 or 5/4. Moist color is 10YR 3/2, 3/3, 4/2, 4/3 or 2.5Y 3/3. Texture is silt loam, fine sandy loam, sandy loam or loam. Clay content ranges from 4 to 22 percent. Reaction ranges from moderately acid to moderately alkaline.
The C horizon dry color is 10YR 5/2, 5/3, 5/4, 6/3, 6/4 or 2.5Y 6/2. Moist color is 10YR 3/2, 4/2, 3/3, 3/4, 4/3, 4/4, 5/2, 2.5Y 4/2 or 4/3. Texture is loam, silt loam, fine sandy loam, very fine sandy loam, loamy sand, loamy fine sand, coarse sandy loam, sand or sandy loam. Clay content ranges from 1 to 15 percent. Reaction ranges from slightly acid to moderately alkaline.
COMPETING SERIES: This is the Maywood series. Maywood soils are on low terraces and flood plains associated with small streams, and have layers of 15 to 35 percent gravel at depths below 36 inches, (91 cm).
GEOGRAPHIC SETTING: Gianella soils are on flood plains, primarily within the active meander belts of the Sacramento River and Feather River. Most areas have been leveled for agriculture. These soils formed in overbank deposited river alluvium from mixed rocks. Slopes range from 0 to 1 percent. Elevation is 70 to 175 feet, (21 to 53 m). The mean annual precipitation is 18 to 23 inches, (457 to 584 mm). The mean annual temperature is 60 to 62 degrees F, (16 to 17 degrees C). Frost free season is 240 to 250 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kusalslough and Parrott soils. Kusalslough soils are fine and occur along the margins between flood plains and basins. Parrott soils are fine-silty and are generally outside the meander belt of the Sacramento River.
DRAINAGE AND PERMEABILITY: Moderately well drained; negligible runoff; moderate to moderately rapid saturated hydraulic conductivity in the A and Ap horizons and moderate to rapid in the C horizons. The soils are rarely to frequently flooded for brief periods in December through March. A fluctuating water table can occur at depths of 33 to over 80 inches, (83 to 203 cm) below the surface of the soil from December through March. Hydrology has been altered both from extensive leveling and by protection from frequent flooding by the Sacramento and Feather River levee systems.
USE AND VEGETATION: This soil is mainly used for walnut and almond orchards and is also used for grain and prunes, wildlife habitat and watershed. Natural vegetation is valley oak, sycamore, willow, cottonwood, grape, blackberry and Pacific poison oak.
DISTRIBUTION AND EXTENT: Butte County, 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 from the Gianella Bridge.
REMARKS: These soils were previously mapped as Columbia in the Soil Survey of Chico Area, California 1926.
Diagnostic horizons and features recognized in this pedon are:
There are no diagnostic horizons.
Particle-size control section - zone from 10 to 40 inches, (25 to 102 cm)
Soil moisture control section - zone from 10 to 26 inches,( 25 to 66 cm) is dry in all parts from about May 1 to October 31 (approximately 140 to 160 days), and is moist in all parts from about December 1 to March 31 (approximately 170 to 190 days).
Additional Data: Characterization data from lab pedon number: 89P0070, NSSL, Lincoln, NE. (sampled as Maywood, correlated to Gianella)