LOCATION SONOMA                  NV

Established Series
Rev. JVC/JBF
11/2019

SONOMA SERIES

The Sonoma series consists of very deep, poorly drained soils that formed in alluvium derived from mixed rocks with a component of volcanic ash. Sonoma soils are on low stream terraces, flood plains, lake plains, and alluvial flats. Slopes are 0 to 2 percent. The mean annual precipitation is about 175 mm and the mean annual temperature is about 10 degrees C.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, calcareous, mesic Aeric Fluvaquents

TYPICAL PEDON: Sonoma silt loam--rangeland. (Colors are for dry soil unless otherwise noted.)

A--0 to 15 cm; gray (10YR 6/1) silt loam, very dark grayish brown (10YR 3/2), moist; moderate thick platy structure; hard, friable, slightly sticky and slightly plastic; many very fine to coarse roots; few fine interstitial pores; moderately alkaline (pH 8.2); clear smooth boundary. (5 to 25 cm thick)

AC--15 to 36 cm; gray (10YR 6/1) silty clay loam, very dark grayish brown (10YR 3/2), moist; weak coarse subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many fine and medium roots; common fine and medium interstitial and tubular pores; strongly alkaline (pH 9.0); clear smooth boundary. (8 to 30 cm thick)

C1--36 to 51 cm; light brownish gray (10YR 6/2) silty clay loam, dark grayish brown (2.5Y 4/2), moist; moderate fine and medium granular structure; hard, friable, moderately sticky, and moderately plastic; many fine and medium roots; common fine and medium interstitial and tubular pores; 1 percent medium prominent dark yellowish brown (10YR 4/4), moist, masses of oxidized iron; strongly alkaline (pH 9.0); clear irregular boundary. (15 to 120 cm thick)

C2--51 to 84 cm; light brownish gray (2.5Y 6/2) silt loam, dark grayish brown (2.5Y 4/2), moist; massive; slightly hard, friable, moderately sticky and moderately plastic; common fine and medium roots; many fine and medium tubular pores; 25 percent medium prominent dark yellowish brown (10YR 4/4), moist, masses of oxidized iron; many fresh water crustacean shell fragments; moderately alkaline (pH 8.4); clear smooth boundary (0 to 38 cm thick)

C3--84 to 170 cm; light yellowish brown (2.5Y 6/4) silt loam, brown (10YR 4/3), moist; massive; slightly hard, friable, moderately sticky and moderately plastic; few fine roots; many fine, medium and few coarse tubular pores; 25 percent medium prominent dark yellowish brown (10YR 4/4), moist, masses of oxidized iron; many fresh water crustacean shell fragments; 2 percent very coarse pale yellow (2.5Y 8/2) carbonate nodules; strongly alkaline (pH 8.6).

TYPE LOCATION: Humboldt County, Nevada; about 4 miles northeast of Winnemucca; about 1,200 feet east and 1,500 feet north of the southwest corner of Section 34, T 37 N, R 38 E; USGS Weso 7.5 minute topographic quadrangle; latitude 41 degrees 02 minutes 12 seconds N and longitude 117 degrees 41 minutes 34 seconds W; WGS84 Decimal Degrees 41.0366667 latitude, -117.6927778 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually saturated and aquic conditions in some part of the moisture control section during winter and spring with the water table at depths below 100 cm during the remainder of the year unless drained; seasonal periods of aquic moisture regime between December and June during saturation with ground water and anaerobic conditions; an aridic moisture regime exists during the growing season in normal years after ground water levels drop below the moisture control section.
Mean annual soil temperature: 9 to 12 degrees C.
Effervescence: Strongly effervescent or violently effervescent.
Calcium carbonate equivalent: 3 to 12 percent.
Other features: Some pedons have buried A horizons within 140 cm.

Particle-size control section - Clay content: 25 to 35 percent.

A and AC horizons
Hue: 10YR or 2.5Y.
Value: 5 through 7 dry, 3 through 5 moist; Value is 6 or 7 dry and 4 or 5 moist when the upper 5 cm of the soil are mixed.
Chroma: 1 through 3, dry or moist.
Reaction: Moderately alkaline through very strongly alkaline (up to pH 9.6).

C horizons
Hue: 10YR through 5Y.
Value: 6 through 8 dry, 3 through 6 moist.
Chroma: 1 or 2, dry or moist. Subhorizons in some pedons have chroma of 3 or 4.
Texture: Stratified silt loam to silty clay loam, with strata of clay or silty clay below 100 cm in some pedons.
Structure: Platy, prismatic, granular, subangular blocky, or is massive.
Consistence: Slightly hard through very hard dry, friable to firm moist; slightly sticky to very sticky; slightly plastic to very plastic wet.
Reaction: Moderately alkaline through very strongly alkaline (up to pH 9.6);
Other features: Fresh-water crustacean shells and 0.5 to 1 cm diameter carbonate concretions are in most pedons; some pedons have few masses of secondary calcium carbonate.

COMPETING SERIES: These are the Bloom, Caneek and Wyasket series.

Bloom soils have gypsum crystals and mean annual soil temperatures mainly warmer than 12 degrees C. Caneek soils do not have an aridic moisture regime and average 18 to 25 percent clay in the particle-size control section. Wyasket soils are warmer than 9 degrees C.

GEOGRAPHIC SETTING: Sonoma soils are on low stream terraces, flood plains, lake plains, and alluvial flats. These soils formed in alluvium derived from mixed rocks with a component of volcanic ash. Slopes are 0 to 2 percent. Elevations range from 1,160 to 1,910 meters. The climate is arid or semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 125 to 250 mm, mean annual temperature is 8 to 11 degrees C, and the frost-free period is 90 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Humboldt and Preble soils. Humboldt soils are fine and have mollic epipedons. Preble soils are coarse-loamy and never saturated.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Poorly drained but most areas of these soils have altered drainage and are now somewhat poorly drained; medium or high surface runoff; moderately high saturated hydraulic conductivity. Endosaturation is present with an apparent seasonal high water table between 40 and 90 cm (shallow and moderately deep free water occurrence classes) between February and June or 100 to 150 cm (deep free water occurrence class) between December and May. Cumulative annual duration class is Common. Some areas have a water table under artesian pressure. These soils are susceptible to flooding that ranges from rare flooding for very brief periods year-round to frequent flooding for long periods between December and June.

USE AND VEGETATION: Sonoma soils are used for irrigated cropland, native pasture, livestock grazing and wildlife habitat. Native vegetation is principally inland saltgrass, creeping wildrye, rush and povertyweed.

DISTRIBUTION AND EXTENT: Northern Nevada. These soils are extensive with about 112,000 acres of the series mapped to date. MLRAs 24, 25, 27, and 28B.

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

SERIES ESTABLISHED: Pershing County (Lovelock Area), Nevada, 1963.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 18 cm (A and part of AC horizons).
Endosaturation - The zone from 36 to 170 cm (The C1, C2 and C3 horizons).
Particle-size control section - The zone from 25 to 100 cm (C1, C2 and parts of the AC and C3 horizons).

ADDITIONAL DATA: Previous authors and editors include: LIL-RAF-TM.
The type location was moved in 8/2009 to better reflect the series concept.

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National Cooperative Soil Survey
U.S.A.