LOCATION FIDDYMENT CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Typic Durixeralfs
TYPICAL PEDON: Fiddyment fine sandy loam - on an east slope of 4 percent under annual grasses and forbs at 130 feet elevation. (Colors are for dry soil unless otherwise stated. When described June 6, 1979, the soil was dry to 15 inches and slightly moist below).
A1--0 to 4 inches; brown (10YR 5/3) fine sandy loam, dark yellowish brown (10YR 3/4) moist; moderate medium platy and subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine roots, many very fine and common fine tubular and many very fine interstitial pores; platy structure at top of horizon; slightly acid (pH 6.5); clear wavy boundary. (4 to 6 inches thick)
A2--4 to 8 inches; brown (10YR 5/3) fine sandy loam, dark yellowish brown (10YR 3/4) moist; massive; very hard, friable, slightly sticky and slightly plastic; common very fine roots; many very fine and common fine tubular and many very fine interstitial pores; slightly acid (pH 6.5); clear wavy boundary. (4 to 6 inches thick)
A3--8 to 15 inches; yellowish brown (10YR 5/4) loam, dark brown (7.5YR 3/4) moist; massive; very hard, friable, slightly sticky and slightly plastic; common very fine roots; many very fine and common fine tubular and many very fine interstitial pores; few skeletans in the bottom part of the horizon; slightly acid (pH 6.5); abrupt wavy boundary. (0 to 8 inches thick)
Bt1--15 to 24 inches; brown (10YR 5/3) clay loam, dark brown (10YR 4/3) moist; strong medium prismatic structure; very hard, firm, sticky and plastic; common very fine roots, common very fine tubular pores; many thick clay films on ped faces, common thin and moderately thick clay films in pores and many moderately thick clay films as bridges between mineral grains; 2 percent 2 to 20 mm pebbles; neutral (pH 7.0); clear wavy boundary. (4 to 12 inches thick)
Bt2--24 to 28 inches; brown (10YR 5/3) clay loam, dark brown (10YR 4/3) moist; strong medium prismatic structure; very hard, firm, sticky and plastic; common very fine roots, common very fine tubular pores; many thick clay films on ped faces, common thin and moderately thick clay films lining pores and many moderately thick clay films as bridges between mineral grains; slightly alkaline (pH 7.8); abrupt smooth boundary. (4 to 12 inches thick)
Bqm--28 to 29 inches; light yellowish brown (10YR 6/4) and very pale brown (10YR 7/4) indurated and strongly cemented silica hardpan, yellowish brown (10YR 5/4) moist; common medium prominent very dark gray (10YR 3/1) mottles; black (10YR 2/1) moist; massive; extremely hard; opal coated laminar cap and strata indurated in more than half of the horizontal plane; moderately alkaline (pH 8.0); abrupt wavy boundary. (0.1 to 3 inches thick)
Bq--29 to 40 inches; very pale brown (10YR 7/3) weakly cemented silica hardpan, brown (10YR 5/3) moist; massive; very and extremely hard; common very fine tubular pores; common to many moderately thick pale brown (10YR 6/3) clay films and colloids, dark brown (7.5YR 4/4) moist, on vertical fracture planes, common thin clay films and colloids lining pores; few opal coatings on fracture planes; moderately alkaline (pH 8.0); clear wavy boundary. (0 to 14 inches thick)
Cr1--40 to 56 inches; light gray (10YR 7/2) siltstone, light brownish gray (10YR 6/2) moist; common medium prominent very dark gray (10YR 3/1) mottles, black (10YR 2/1) moist; extremely hard but cut with difficulty with tile spade or auger; many very fine tubular and common very fine interstitial pores; many moderately thick brown (7.5YR 4/4) dry and moist, clay films and colloids on vertical fracture planes; moderately alkaline (pH 8.0); clear wavy boundary. (5 to 20 inches thick)
Cr2--56 to 64 inches; light gray (10YR 7/2) siltstone, light brownish gray (10YR 6/2) moist; common medium prominent very dark gray (10YR 3/1) mottles, black (10YR 2/1) moist; extremely hard but cut with difficulty with tile spade or auger; many very fine tubular and interstitial pores; common medium distinct brown (7.5YR 4/4) dry and moist, colloidal stains on cross sections; moderately alkaline (pH 8.0).
TYPE LOCATION: Sacramento County, California; 0.5 miles south of the southern boundary of Mather Air Force Base, 2,420 feet south and 350 feet east of the intersection of Keifer and Sunrise Boulevards, and of the northwest corner section 29, T.8 N., R.7 E., MDB&M.
RANGE IN CHARACTERISTICS: Thickness of solum and depth to duripan is 20 to 40 inches. A paralithic contact immediately underlies the duripan. Average clay content of the textural control section is 27 to 35 percent. The mean annual soil temperature ranges from 62 to 67 degrees F. The soil between depths of 8 and 21 inches is moist in all parts from December through April and is dry in all parts from June through mid-October in most years. Increase in clay content at an abrupt boundary within or at the upper boundary of the argillic horizon is 15 to 25 percent, absolute, within 1 inch. Content of coarse plus very coarse sand is less than 15 percent throughout the profile.
The A horizon is 7.5YR 6/4, 5/4; 10YR 6/4, 6/3, 6/2, 5/4, 5/3 or 5/2. Moist color is 7.5YR 4/4, 3/4, 3/2; 10YR 3/4, 3/3 or 3/2. Texture is sandy loam, fine sandy loam, loam or silt loam with 10 to 18 percent clay. Organic carbon is less than 0.6 percent below 6 inches. Reaction is moderately acid to neutral.
Some pedons have a BA or BAt horizon. It is 7.5YR 6/4, 5/4; 10YR 7/3, 6/4 or 5/3. Moist color is 7.5YR 4/4, 3/4; 10YR 4/3 or 3/4. Texture is loam or sandy loam with 10 to 18 percent clay. Reaction is medium acid to neutral.
The Bt horizon is 7.5YR 6/4, 5/4; 10YR 7/3, 6/3, 5/4 or 5/3. Moist color is 7.5YR 4/4, 3/4; 10YR 4/3, 3/4; 5YR 3/4 or 4/4. Texture is a sandy clay loam or clay loam with 27 to 35 percent clay. Clay content increases with depth. Reaction is slightly acid to slightly alkaline.
The Bqm horizon is 10YR 7/4, 7/3, 7/2, 6/4, 6/3, 5/3; 7.5YR 6/6, 6/3 or 5/4. Moist color is 10YR 6/2, 5/4, 5/3 4/3, 3/4; 7.5YR 4/4, or 4/6. It is platy or massive, and strongly cemented to indurated with silica. It has opal coatings on more than one-half of the horizontal plane area at its upper boundary or is indurated below its upper boundary. It is neutral to slightly alkaline and noncalcareous.
COMPETING SERIES: These are Buchenau, Exeter, Monserate, and Rocklin series. Buchenau, Exeter and Monserate soils lack a paralithic contact immediately underlying the duripan. Rocklin has more than 15 percent very coarse plus coarse sand.
GEOGRAPHIC SETTING: The Fiddyment soils are on low terraces and hills at elevations of 50 to 350 feet. Slopes are 0 to 15 percent. The soils are formed in material weathered from valley fill sediments from mixed rock sources of the Fair Oaks or Laguna Formations. The sediments are weakly to moderately consolidated sandstone and siltstone. In some areas the sediments have thin discontinuous strata of tuff. The climate is subhumid with hot, dry summmers and cool moist winters. Mean annual precipitation is 15 to 25 inches. Mean January temperature is 44 to 46 degrees F; mean July temperature 76 to 79 degrees F; and mean annual temperature is 60 to 62 degrees F. Frost-free season is 230 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alamo, Cometa, Kaseburg, Liveoak, Orangevale and San Joaquin soils. Alamo, Cometa and San Joaquin soils are fine. Kaseburg soils are shallow. Liveoak and Orangevale soils lack cemented or consolidated substrata. Liveoak soils are on high floodplains. Kaseburg soils are on the same landscape position. Orangevale soils are on high terraces. Alamo and San Joaquin soils are on low terraces.
DRAINAGE AND PERMEABILITY: Well drained, slow to medium runoff, very slow permeability. Water perches above the claypan for short periods after periods of high rainfall in December through April.
USE AND VEGETATION: The soil is used for rangeland, non-irrigated small grain crops and urban development. Some areas are used for irrigated pasture. Natural vegetation is annual grasses and forbs such as soft chess, oats, and filaree and a few scattered oaks.
DISTRIBUTION AND EXTENT: Hills and terraces on the eastside of the Sacramento Valley. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Placer County, California, Western Part, 1975.
REMARKS: This soil was previously mapped as the Whitney soil in Sacramento County. The type location has been moved to this site in Sacramento County because it more closely represents the series concept of a fine-loamy soil with an abrupt boundary and with very slow permeability. In some pedons, the A horizon is very strongly acid or strongly acid because of the addition of fertilizers.
The activity class was added to the classification in March of 2003. Competing series were not checked at that time. - ET
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: the zone from the surface to 15 inches (A1, A2, A3 horizons)
Argillic horizon: the zone from 15 to 28 inches (Bt1, Bt2 horizon)
Duripan - the zone from 28 to 40 inches (Bqm, Bq horizons) continously indurated at upper boundary.
Paralithic contact - at 40 inches (Cr1, Cr2 horizons) fragments breakdown after shaking in water.
ADDITIONAL DATA: Lincoln Laboratory Sample No. S79CA067-4 (this pedon). Additional sites sampled as S82CA067-8 in Sacramento County by Lincoln Laboratory and S69 Calif. 31-13 in Placer County by Riverside Laboratory.