LOCATION SCRIBNER CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Cumulic Endoaquolls
TYPICAL PEDON: Scribner clay loam, drained, on an east facing slope of 1 percent under forbs and annual grasses at 8 feet (colors are for dry soil unless otherwise stated). When described on October 17, 1978, the soil was moist throughout.
Ap1--0 to 4 inches; gray (10YR 5/1) clay loam, very dark gray (10YR 3/1) moist; weak fine subangular blocky structure with the upper inch being moderate medium granular structure; very hard, firm, sticky and plastic; many very fine and few fine roots; common very fine tubular and interstitial pores; many worm casts; 4.3 percent organic matter; neutral (pH 7.0); clear smooth boundary. (4 to 12 inches thick)
Ap2--4 to 12 inches; mixed grayish brown (10YR 5/2) and strong brown (7.5YR 4/6) clay loam, very dark gray (10YR 3/1) moist; weak fine subangular blocky structure; very hard, firm, sticky and plastic; many very fine and few fine roots; common very fine tubular and interstitial pores; 1.7 percent organic matter; mildly alkaline (pH 7.8); clear wavy boundary. (5 to 9 inches thick)
A--12 to 21 inches; gray (10YR 5/1) clay loam, very dark gray (10YR 3/1) moist; weak fine subangular blocky structure; very hard, firm, sticky and plastic; many very fine and few fine roots; common very fine tubular and interstitial pores; some bleached light gray (10YR 7/1) sand grains; 3 percent organic matter, moderately alkaline (pH 8.0); clear wavy boundary. (6 to 12 inches thick)
Ab--21 to 39 inches; gray (10YR 5/1) clay loam, very dark gray (10YR 3/1) moist; common medium distinct yellowish red (5YR 5/8) mottles, yellowish red (5YR 5/6) moist; moderate fine angular blocky structure; very hard, firm, sticky and plastic; many very fine roots; common very fine tubular and interstitial pores; moderately alkaline (pH 8.2); gradual wavy boundary. (10 to 20 inches thick)
C1--39 to 51 inches; gray (10YR 5/1) clay loam, dark gray (10YR 4/1) moist; many fine and medium distinct yellowish red (5YR 5/8) mottles, yellowish red (5YR 5/6) moist; moderate medium angular blocky; very hard, firm, sticky and plastic; common very fine roots; common very fine tubular and interstitial pores; moderately alkaline (pH 8.0); diffuse wavy boundary. (0 to 20 inches thick)
C2--51 to 60 inches; light brownish gray (2.5Y 6/2) sandy clay loam, dark grayish brown and brown (10YR 4/2, 5/2) moist; many fine and medium strong brown (7.5YR 5/6) mottles, yellowish red (5YR 5/6) moist; moderate medium angular blocky structure, extremely hard, very firm, sticky and plastic; common very fine roots; common very fine tubular and interstitial pores; strongly effervescent, lime segregated in few fine filaments; moderately alkaline (pH 8.0).
TYPE LOCATION: Sacramento County, California; about 0.7 mile south of Hood, 0.57 mile south of the intersection of Hood-Franklin Road and Highway 160, 0.4 mile southeast on farm road, 40 feet north of farm road near edge of pear orchard in a small abandoned site, 2,100 feet south and 1,400 feet east of the northeast corner of sec. 23, T. 6 N., R. 4 E., in an unsectionized area of T. 6 N., R. 4 E. 38 degrees 21 minutes 30 seconds, N Latitude, 121 degrees 29 minutes, 30 seconds W Longitude.
RANGE IN CHARACTERISTICS: The weighted average clay content in the 10 to 40 inch control section is 25 to 35 percent with 15 to 45 percent fine sand or coarser. The organic matter content decreases irregularly with depth and ranges from 1 to 10 percent weighted average, in the control section. The mollic epipedon is 24 to more than 40 inches thick and has distinct or prominent mottles in the lower part. The mean annual soil temperature is about 62 degrees F.
The Ap and upper part of the A horizon are 10YR 5/1, 4/1, 3/1, 5/2, 4/2; 5Y 5/1, 4/1 or 4/2; 2.5Y 5/2. Moist colors are 10YR 3/1, 2/1, 3/2; 5Y 3/1 or 3/2; 2.5Y 3/2. Texture is clay loam and silt loam. Organic matter content is 2 to 10 percent. Reaction is slightly acid to slightly alkaline.
The lower part of the A horizon and the Ab horizon are 10YR 5/1, 4/1, 3/1, 5/2, 4/2, 3/2; 2.5Y 4/2 or 5/2; 5Y 5/1, 4/1, 4/2, 3/1, 2/1; or N 2/0. Moist colors are 10YR 3/1, 2/1, 3/2, 2/2; 2.5Y 3/2 or 4/2; 5Y 3/1, 3/2, 2.5/1; or N2/0. Texture is clay loam, loam or silty clay loam stratified with silt loam. Clay content is 25 to 35 percent. Reaction is neutral to moderately alkaline.
The C horizon is 10YR 6/1, 5/1, 5/2, 5/3, 6/2; 2.5Y 6/2; 5Y 6/1 or 6/2. Moist colors are 10YR 5/1, 4/1, 3/1, 4/2, 4/3, 3/3, 5/3; 2.5Y 4/2; 5Y 4/1 or 4/2. Texture is stratified fine sandy loam, loam, silt loam, sandy clay loam, clay loam and silty clay loam. In some areas texture below a depth of 40 inches is fine sand, sand or loamy sand. Reaction is neutral to moderately alkaline. Some pedons are calcareous below 40 inches.
COMPETING SERIES: These are the Kanebreak (TX), Ryde (CA) and Sikeston (MO) series. Ryde soils have a weighted average organic matter content of 10 to 30 percent in the 10 to 40 inch control section. The Kanebreak soils have mean annual soil temperatures greater than 63 degrees F. The Sikeston soils have prismatic structure within the control section and also lack buried A horizons.
GEOGRAPHIC SETTING: Scribner soils are on edges of backswamps on the flood plain or delta of the Sacramento and San Joaquin Rivers. These soils formed in alluvium from mixed rocks. Elevations are 10 feet below sea level to 75 feet. The climate is characterized by warm dry summers and cool moist winters. Mean annual precipitation is 13 to 16 inches. The mean January temperature is 44-46 degrees F; the mean July temperature is 73-76 degrees F; and the mean annual temperature is 59 to 62 degrees F. The frost-free period is 225 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Egbert, Gazwell, Peltier and Sailboat soils. Egbert, Gazwell and Peltier series have a fine textured control section and are on slightly lower positions. Sailboat soils have an ochric epipedon and are on low natural levees.
DRAINAGE AND PERMEABILITY: Poorly drained; negligible to low runoff; moderately slow and slow permeability (sandy substratum phase has rapid permeability below a depth of 40 inches). The drainage of these soils has been altered by the use of levees and pumps. In December through April, the water table is maintained between a depth of 36 to 60 inches but is sometimes as shallow as 20 inches. These soils are protected by levees and have a rare hazard of flooding.
USE AND VEGETATION: Used mainly for irrigated cropland. The principal crops are tomatoes, corn and small grains.
DISTRIBUTION AND EXTENT: Mainly in the Sacramento and San Joaquin River delta area. The soil is moderately extensive in MLRA-16, 17.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Sacramento County, California, 1987.
REMARKS: The Scribner series consists of a split of the wide organic matter range of the Ryde series. Ryde will have a weighted average organic matter content of 10-30 percent in the control section. Organic matter content in the typical pedon from SSO LaMotte kit.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface to a depth of 39 inches (Ap1, Ap2, A, Ab)
Series classification updated 6/96. Competing series not updated at that time.