LOCATION PAHRANAGAT              NV+UT

Established Series
Rev. BAL/DJM/RLB/BKP
06/2016

PAHRANAGAT SERIES

The Pahranagat series consists of very deep, very poorly or poorly drained soils that formed in mixed alluvium derived from volcanic rocks and reworked lacustrine deposits. The Pahranagat soils are on floodplains, stream terraces, fan aprons, or alluvial flats. Slopes are 0 to 4 percent. The mean annual precipitation is about 200 mm and the mean annual temperature is about 11 degrees C.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, calcareous, mesic Fluvaquentic Endoaquolls

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

Ap--0 to 10 cm; brown (10YR 4/3) silt loam, dark brown (10YR 3/3) moist; strong very fine and fine subangular blocky structure; slightly hard, very friable, slightly sticky and moderately plastic; many very fine and fine and few medium roots; common very fine and fine and few medium and coarse tubular pores; slightly effervescent; moderately alkaline (pH 8.0); abrupt smooth boundary. (0 to 15 cm thick)

Ag--10 to 41 cm; grayish brown (10YR 5/2) silty clay loam, very dark brown (10YR 2/2) moist; few fine distinct dark brown (7.5YR 3/4) mottles; strong fine subangular blocky structure; slightly hard, friable, moderately sticky and very plastic; common very fine through coarse roots; common very fine through coarse tubular pores; common medium dark gray (10YR 4/1) and black (10YR 2/1) worm casts; strongly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (25 to 36 cm thick)

2Cg--41 to 64; light gray (10YR 7/2) very fine sandy loam, dark grayish brown (10YR 4/2) moist; few fine faint brown (7.5YR 4/4) mottles; massive; slightly hard, very friable, slightly sticky and slightly plastic; common fine and medium roots; common medium and coarse tubular pores; common medium dark gray (10YR 4/1) and black (10YR 2/1) worm casts; strongly effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (3 to 25 cm thick)

3Agb--64 to 89 cm; light brownish gray (10YR 6/2) silty clay, very dark brown (10YR 2/2) moist; few fine distinct brown (7.5YR 4/4) mottles; strong fine subangular blocky structure; hard, firm, very sticky and very plastic; common medium roots; few medium and coarse tubular pores; violently effervescent; strongly alkaline (pH 8.6); clear wavy boundary. (3 to 25 cm thick)

4Cg1--89 to 114 cm; light gray (10YR 7/2) silty clay loam, dark grayish brown (10YR 4/2) moist; many medium distinct olive brown (2.5Y 4/4) and few fine distinct brown (7.5YR 4/4) mottles; massive; hard, firm, moderately sticky and very plastic; few medium roots; few medium tubular pores; violently effervescent; strongly alkaline (pH 8.6); clear wavy boundary. (3 to 25 cm thick)

4Cg2--114 to 152 cm; light brownish gray (2.5Y 6/2) silty clay loam, dark grayish brown (2.5Y 4/2) moist; common fine prominent brown (7.5YR 4/4) mottles; massive; hard, firm, moderately sticky and very plastic; few medium roots; few medium tubular pores; violently effervescent; strongly alkaline (pH 8.6).

TYPE LOCATION: Lincoln County, Nevada; approximately 5000 feet west of Barclay; about 1400 feet west and 2300 feet south of the northeast corner of section 16, T. 5 S., R. 69 E.; USGS Islen 7.5 minute topographic quadrangle; latitude 37 degrees 30 minutes and 51 seconds N and longitude 114 degrees 16 minutes and 31 seconds W; WGS84 Decimal Degrees 37.5141667 latitude -114.2752778 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Saturated for at least one or more months during most years.
Soil temperature: 12 to 15 degrees C.
Mollic epipedon thickness: 25 to 50 cm.
Reaction: Moderately alkaline or strongly alkaline.
Carbonates: Slightly effervescent through violently effervescent.
Other features: One or more buried Ag horizons range in thickness from 3 to 25 cm.

Particle-size control section - Clay content: Averages between 18 and 35 percent.
Sand: Averages less than 15 percent fine and coarser sand when mixed.
Rock Fragments: 0 to 10 percent.

Ap horizon
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 1 or 2, dry or moist
Other features: This horizon averages about 3 to 8 percent organic matter and ranges from 5 to 20 percent. Some pedons have 10 cm or less of lightly colored overwash on the surface.
Mineralogy: 5 to 20 percent volcanic glass in the 0.02 to 2 mm fraction and averages 0.01 to 0.05 percent Al plus 1/2Fe, extracted by ammonium oxalate.

Ag horizon
Hue: 10YR or 2.5Y.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 1 or 2, dry or moist.
Other features: This horizon averages about 1 to 3 percent organic matter and ranges from 1.5 to 15 percent.
Mineralogy: 5 to 20 percent volcanic glass in the 0.02 to 2 mm fraction and averages 0.01 to 0.05 percent Al plus 1/2Fe, extracted by ammonium oxalate.

C horizons
Hue: 10YR through 5Y.
Value: 5 through 7 dry, 3 through 5 moist.
Chroma: 1 or 2, dry or moist.
Texture: Stratified very fine sandy loam, loam, silt loam, silty clay and silty clay loam.

COMPETING SERIES: These are the Colville, Gibbon, Kittitas and Paranat soils.

Colville soils have a cambic horizon and a Bq and Cq horizons. Gibbon soils have 5 to 15 percent calcium carbonates equivalent throughout the control section and receive 500 to 760 mm of precipitation. Kittitas soils have more than 15 percent exchangeable sodium in the mollic epipedon. Paranat soils have mean annual soil temperature of 8 to 11 degrees C.

GEOGRAPHIC SETTING: Pahranagat soils are on floodplains, stream terraces, fan aprons, or alluvial flats. These soils formed in alluvium derived from volcanic rocks and reworked lacustrine deposits. Slopes are 0 to 4 percent. Elevations are 1,070 to 1,700 meters. The mean annual precipitation is 125 to 200 mm, semi-arid with cool moist winters and hot dry summers, the mean annual temperature is 11 to 14 degrees C, and the frost-free season is 110 to 160 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ash Springs, Bastian, Heist, and Patter soils. Ash Springs soils have coarse-loamy particle-size control sections and calcic horizons. Bastian soils have fine-loamy particle-size control sections and contain durinodes. Heist soils have coarse-loamy particle-size control sections and are well drained. Patter soils have coarse-loamy particle-size control sections and a cambic horizon.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Very poorly or poorly drained; runoff is very slow; moderately low saturated hydraulic conductivity. The water table ranges from at or near the soil surface in seeped areas to 50 cm. Drained phases are recognized.

USE AND VEGETATION: Used for growing alfalfa, small grains, improved grass-legume pasture, and native hay or pasture. Potential native vegetation includes basin big sagebrush, basin wildrye, and western wheatgrass. This pedon is correlated to ecological site R029XY003NV, Loamy Bottom 8-12 P.Z.

DISTRIBUTION AND EXTENT: Southeastern Nevada and southwestern Utah. MLRA 29. These soils are not extensive.

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

SERIES ESTABLISHED: Lincoln County, Nevada, 1940.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the surface to 41 cm (Ap and Ag horizons).
Endosaturation - The zone from 41 to 152 cm (Ag, 2Cg, 3Agb, 4Cg1 and 4Cg2 horizons).
Fluvaquentic features - This soil is stratified and has an irregular decrease in organic matter.
Particle-size control section - The zone from 25 to 100 cm (Ag, 2Cg, 3Agb and part of the 4Cg1 horizon).

Classification was changed in 1992 from Haplaquolls to Endoaquolls.

ADDITIONAL DATA: The concept of this series where it was mapped should be reviewed during the MLRA update, especially for water table depths and drainage classes.

---

National Cooperative Soil Survey
U.S.A.