LOCATION SHIMA                   CA

Established Series
Rev. PGN-WBS-MAM-ET
05/2016

SHIMA SERIES

The Shima series consists of very deep, very poorly drained soils formed in highly decomposed organic material underlain by coarse textured alluvium from mixed sources. Shima soils are in fresh water marshes and river channels. Slope is less than 2 percent. The annual precipitation is about 381 millimeters (15 inches) and the annual temperature is about 16 degrees C (60 degrees F).

TAXONOMIC CLASS: Sandy or sandy-skeletal, mixed, euic, thermic Terric Haplosaprists

TYPICAL PEDON: Shima muck-on a west facing slope of less than 1 percent in a cultivated asparagus field at 2.4 meters (8 feet) below sea level. (Colors are for moist soil unless otherwise stated.)

Oap --0 to 20 centimeters (0 to 8 inches); black (10YR 2/1) muck, black (10YR 2/1) rubbed, very dark gray (10YR 3/1) dry; less than 5 percent tule and reed fibers before rubbing and a trace after rubbing; weak fine granular structure; slightly hard, loose, nonsticky and nonplastic; very strongly acid (pH 4.6); gradual smooth boundary. (20 to 25 centimeters (8 to 10 inches) thick)

Oa --20 to 53 (8 to 21) inches; black (10YR 2/1) muck, black (10YR 2/1) rubbed, very dark gray (10YR 3/1) dry; less than 5 percent tule and reed fibers before rubbing and a trace after rubbing; weak coarse prismatic and weak fine granular structure; soft, very friable, nonsticky and nonplastic; very strongly acid (pH 4.5); clear wavy boundary. (20 to 64 centimeters (8 to 25 inches) thick). There is a lens of ashy material (burned peat) 0.5 to 1.5 inches thick between the Oa and 2C1 horizon which is brown (7.5YR 4/4) with many medium prominent yellowish red (5YR 4/8) mottles. It is slightly acid (pH 6.5).

2C1 --53 to 58 centimeters (21 to 23 inches); black (10YR 2/1) mucky clay loam, very dark gray (10YR 3/1) dry; many medium prominent yellowish red (5YR 4/8) redox concentrations; massive; slightly hard, firm, sticky and plastic; common fine tubular pores; neutral (pH 7.0); abrupt smooth boundary. (0.75 to 3 inches thick)

3C2 --58 to 99 centimeters (23 to 39 inches); light olive brown (2.5Y 5/4) loamy sand; with many medium prominent reddish brown (5YR 5/4) and dark gray (N 4/0) redox concentrationsand depletions, light brownish gray (2.5Y 6/2) dry; massive; loose, nonsticky and nonplastic; few fine roots; many very fine interstitial pores; slightly effervescent with few fine soft masses; slightly alkaline (pH 7.8); abrupt smooth boundary. (2.5 to 41 centimeters (1 to 16 inches) thick)

3C3 --99 to 152 centimeters (39 to 60 inches); olive brown (2.5Y 4/4) loamy sand, many medium distinct dark gray (N 4/0) and reddish brown (5YR 4/4) redox depletions and concentrations, light yellowish brown (2.5Y 6/4) dry; massive; loose, nonsticky and nonplastic; many very fine interstitial pores; moderately alkaline (pH 7.9).

TYPE LOCATION: San Joaquin County; California; Rindge Tract; 1,000 feet NW of Fourteen Mile Slough; 0.8 miles NE of the junction of the Stockton Deep Water Channel and Fourteen Mile Slough; 38 degrees, 00 minutes, 25 seconds N latitude and 121 degrees, 24 minutes, 19 seconds W longitude in an unsectionized area. Terminous Quad.

RANGE IN CHARACTERISTICS:
Depth to mineral layer ranges from 43 to 91 centimeters (17 to 36 inches).
Mean annual soil temperature: 17 degrees C (62 degrees F)
Orgnic matter: Organic layers have from 40 to 65 percent but typically range from 40 to 55 percent
Fiber content: trace to 40 percent before rubbing and none to 10 percent after rubbing
Other features: An ash lens is absent in some pedons between the Oa layer and the underlying mineral layer

The Oa horizon:
Hue: 10YR or N moist, 10YR dry
Value: 2 moist, 3or 4 dry
Chroma: 1 or 0 dry and moist
Organic matter: Upper part is 40 to 50 percent organic matter with a trace to 5 percent fibers remaining after rubbing. The lower part has 45 to 65 percent organic matter and has from a trace to 10 percent fibers remaining after rubbing.
Structure: Weak to strong granular
Reaction: very slightly acid.

The upper C horizon:
Hue: 10YR
Value: 2 moist, 3 dry
Chroma: 1 moist and dry
Texture of the fine earth: Mucky clay loam or mucky silty clay
Reaction: Very strongly acid to neutral.

The lower C horizon:
Hue: 2.5Y moist or dry
Value: 5 or 4 moist, 6 dry
Chroma: 4 moist, 2 or 4 dry
Texture of the fine earth: Sand, loamy sand, or loamy fine sand
Reaction: Very strongly acid to moderately alkaline depending on the moisture content

COMPETING SERIES: This is the Currituck series. Currituck soils have a tide influenced fluctuating water table, formed in sandy marine deposits, range to extremely acid in the mineral layer and lower organic layer and have chromas of 2 or less throughout.

GEOGRAPHIC SETTING: The Shima soils are in fresh water marshes and river channels of the San Joaquin-Sacramento Delta. Slopes are less than 2 percent. They formed in hydrophytic plant remains and mixed mineral alluvium. The organic material is derived from tule and reed fibers. Elevations are 1.5 above to 4.9 meters below sea level (5 feet above to 15 feet below sea level) and are on islands protected by levees. The climate is subhumid with hot dry summers and cool, moist winters. The mean annual precipitation is 356 to 406 millimeters (14 to 16 inches). The mean January temperature is about 7 degrees C (45 degrees F); the mean July temperature is about 24 degrees C (75 degrees F); mean annual temperature is about 15 degrees C (60 degrees F). Frost-free season ranges from 260 to 300 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the similar Kingile and Rindge soils and the Dello, Peltier, Retryde and Venice soils. Dello soils are sandy mineral soils. Peltier soils are mineral soils that are fine. Retryde soils are mineral soils that are fine-loamy. Venice soils have hemic organic materials to a depth of 130 centimeters (51 inches) or more. Kingile soils have clayey mineral material at depths of 43 to 91 centimeters (17 to 36 inches). Rindge soils have continuous sapric organic materials to a depth of 130 centimeters (51 inches) or more.

DRAINAGE AND PERMEABILITY: Very poorly drained; very slow runoff; permeability is moderate in the mucky mineral horizon and very rapid in the mineral substratum. The water table is lowered by artificial drainage with open drains and pumps. The water table is usually maintained between a depth of 91 to 122 centimeters (36 to 48 inches) during the growing season and at or near the surface sometimes during the winter months.

USE AND VEGETATION: The Shima soils are used for irrigated cropland to grow field crops, vegetable crops and specialty crops. Native vegetation in uncultivated areas is sedges and tules.

DISTRIBUTION AND EXTENT: Shima soils are in the islands of the Sacramento-San Joaquin Delta of California. This series is of small extent in MLRA-16.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Contra Costa County Area, California, 1973.

REMARKS: The classification was updated in February 2001 using the Eighth Edition to Soil Taxonomy. This series was formerly classified as sandy or sandy-skeletal, mixed, euic, thermic Terric Medisaprists. Competing series checked in 2016.

Diagnostic horizons and features recognized in this pedon are:

Histic epipedon - 0 to 53 centimeters (0 to 21 inches) (Oap, Oa); sapric material.

ADDITIONAL DATA: This soil was laboratory sampled as 72C0090 (S1972CA077007) and 14N0997 S2014CA077002).

---

National Cooperative Soil Survey
U.S.A.