LOCATION TWOJAYAY                CA

Established Series
Rev. EWB-AMB-JBF-TM
06/2017

TWOJAYAY SERIES

The Twojayay series consists of very deep, somewhat poorly drained soils that formed in alluvium derived from mixed rocks. Twojayay soils are on stream terraces. Slopes are 0 to 4 percent. The mean annual precipitation is about 250 mm and the mean annual temperature is about 6 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, calcareous, frigid Vitrandic Torriorthents

TYPICAL PEDON: Twojayay ashy sandy loam--pastureland. (Colors are for dry soil unless otherwise noted.)

A--0 to 20 cm; light gray (10YR 7/2) ashy sandy loam, grayish brown (10YR 5/2) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and common fine roots; many very fine interstitial pores; strong effervescence; very strongly alkaline (pH 9.6); clear smooth boundary. (13 to 25 cm thick)

C1--20 to 50 cm; light brownish gray (2.5Y 6/2) loam, dark grayish brown (2.5Y 4/2) moist; 5 percent medium very dark gray (10YR 3/1) redox depletions; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine tubular and interstitial pores; strong effervescence; very strongly alkaline (pH 9.6); clear wavy boundary. (20 to 30 cm thick)

C2--50 to 66 cm; light brownish gray (2.5Y 6/2) loam, dark grayish brown (2.5Y 4/2) moist; 25 percent fine and medium yellowish brown (10YR 5/4) redox concentrations; massive; hard, friable, moderately sticky and moderately plastic; few very fine and fine roots; common very fine and fine tubular and interstitial pores; strong effervescence; very strongly alkaline (pH 9.6); clear wavy boundary. (10 to 20 cm thick)

C3--66 to 81 cm; light brownish gray (2.5Y 6/2) loam, very dark grayish brown (2.5Y 3/2) moist; 25 percent fine yellowish brown (10YR 5/6) redox concentrations; massive; hard, friable, moderately sticky and moderately plastic; few very fine and fine roots; common very fine and fine interstitial pores; slight effervescence; very strongly alkaline (pH 9.2); clear wavy boundary. (15 to 25 cm thick)

C4--81 to 112 cm; light brownish gray (2.5Y 6/2) fine sandy loam, dark grayish brown (2.5Y 4/2) moist; 25 percent coarse yellowish brown (10YR 5/4) redox concentrations; massive; slightly hard, very friable, slightly sticky and nonplastic; few very fine roots; common very fine tubular and interstitial pores; slight effervescence; strongly alkaline (pH 9.0); clear wavy boundary. (20 to 32 cm thick)

C5--112 to 127 cm; light brownish gray (2.5Y 6/2) loam, dark grayish brown (2.5Y 4/2) moist; 25 percent medium yellowish brown (10YR 5/4) redox concentrations; massive; hard, friable, moderately sticky and moderately plastic; few very fine roots; common very fine tubular and interstitial pores; slight effervescence; strongly alkaline (pH 8.8); clear wavy boundary. (0 to 20 cm thick)

C6--127 to 152 cm; light brownish gray (2.5Y 6/2) stratified sandy clay loam to coarse sand, dark grayish brown (2.5Y 4/2) moist; strong brown (7.5YR 5/6) redox concentrations; massive; soft, very friable, nonsticky and nonplastic; few very fine roots; common very fine tubular and interstitial pores; slight effervescence; strongly alkaline (pH 8.8).

TYPE LOCATION: Mono County, California; in Bridgeport Valley; about 1,050 feet south and 3,890 feet east of the northwest corner, section 18, T. 5 N., R. 25 E.; Mount Jackson USGS 7.5 minute topographic quadrangle; latitude 38 degrees 17 minutes 0.49 seconds N and longitude 119 degrees 15 minutes 16.43 seconds W; WGS84 Decimal Degrees 38.2834694, latitude, -119.2545639 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry in the moisture control section; moist winter and spring; usually dry summer and fall; aridic moisture regime that borders on xeric. Saturated within 75 to 100 cm during the late winter and early spring in most years.
Mean annual soil temperature: 7 to 8 degrees C.
Depth to stratified layers with more than 35 percent rock fragments and/or sandy textures: 100 to more than 150 cm in some pedons.

Particle-size control section - Clay content: Averages 18 to 25 percent.
Rock fragments: Averages 0 to 15 percent, mainly gravel. Lithology of rock fragments is mixed, dominantly igneous rocks.

A horizons
Hue: 10YR or 2.5Y.
Value: 5, 6 or 7 dry, 3, 4 or 5 moist.
Chroma: 2 or 3, dry or moist.
Effervescence: Strongly effervescent or violently effervescent.
Salinity (EC): 8 to 16 mmhos/cm.
Sodicity (SAR): 31 to 45.
Reaction: Strongly alkaline or very strongly alkaline.
Calcium carbonate equivalent: 1 to 5 percent.
Volcanic glass content: 30 to 50 percent in coarse silt through fine sand fractions.

C1 and C2 horizons
Hue: 10YR or 2.5Y.
Value: 5, 6 or 7 dry, 3, 4 or 5 moist.
Chroma: 2 or 3, dry or moist.
Texture: Loam, fine sandy loam or sandy loam.
Clay content: Averages 18 to 25 percent.
Rock fragments: Averages less than 15 percent.
Effervescence: Strongly effervescent or violently effervescent.
Salinity (EC): 8 to 16 mmhos/cm.
Sodicity (SAR): 31 to 45.
Reaction: Strongly alkaline or very strongly alkaline.
Calcium carbonate equivalent: 1 to 5 percent.

C3, C4 and C5 horizons
Hue: 10YR or 2.5Y.
Value: 5 through 7 dry, 3 through 5 moist.
Chroma: 1, 2 or 3, dry or moist.
Texture: Sandy loam, fine sandy loam or loam.
Clay content: Averages 18 to 25 percent.
Rock fragments: Averages less than 15 percent.
Salinity (EC): 4 to 16 mmhos/cm.
Sodicity (SAR): 13 to 30.
Reaction: Strongly alkaline or very strongly alkaline
Effervescence: Slightly effervescent or strongly effervescent.
Calcium carbonate equivalent: 1 to 3 percent.

C6 horizon
Hue: 10YR or 2.5Y.
Value: 5 through 7 dry, 4 or 5 moist.
Chroma: 1, 2 or 3, dry or moist.
Texture: Stratified clay loam to coarse sand.
Clay content: Averages 5 to 10 percent.
Salinity (EC): 4 to 16 mmhos/cm.
Sodicity (SAR): 13 to 30.
Reaction: Moderately alkaline or strongly alkaline.
Effervescence: Slightly effervescent or strongly effervescent.
Calcium carbonate equivalent: 1 to 3 percent.

COMPETING SERIES: There are currently no other series in this family.

GEOGRAPHIC SETTING: Twojayay soils are on stream terraces. They typically occur on summit positions. They formed in alluvium derived from mixed rocks. Slopes are 0 to 2 percent. Elevations range from 1,955 to 2,015 meters. The climate is semi-arid with cool, moist winters and warm, dry summers. The mean annual precipitation is 200 to 300 mm, mean annual temperature is 6 to 7 degrees C., and the frost-free period is 30 to 60 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Eastwalker, Goodbye and Patididit series. Eastwalker and Goodbye soils have a mollic epipedon. Patididit soils lack secondary carbonates within 20 cm of the soil surface.

DRAINAGE AND PERMEABILITY: Somewhat poorly drained; low surface runoff; moderately rapid permeability; moderately low saturated hydraulic conductivity. Endosaturation is present with an apparent seasonal high water table between 75 and 100 cm (moderately deep free water occurrence class) between January and June. Cumulative annual duration class is common. These soils are susceptible to rare flooding for very brief periods year round.

USE AND VEGETATION: Twojayay soils are used for pastureland, recreation, watershed and wildlife habitat. The native vegetation is mainly rushes.

DISTRIBUTION AND EXTENT: Eastern California, east of the Sierra Nevada Range. These soils are not extensive. MLRA 26.

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

SERIES ESTABLISHED: Mono County (Coleville-Bridgeport Area), California, 2010.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 18 cm (part of the A horizon)
Aquic conditions - The conditions of endosaturation and reduction in horizons between 75 and 152 cm (lower C3, C4, C5 and C6 horizons).
Vitrandic intergrade feature - The zone from the soil surface to 20 cm (A horizon).
Stratified layers - The zone from 127 to 152 cm (C6 horizon).
Particle-size control section - The zone from 25 to 100 cm (C1, C2, C3 and C4 horizons).

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National Cooperative Soil Survey
U.S.A.