LOCATION ARMYDRAIN NV

Established Series
Rev. GAM/RLB/JBF
05/2016

ARMYDRAIN SERIES

The Armydrain series consists of very deep, poorly drained soils that formed in alluvium derived from mixed rocks. The Armydrain soils are on flood plains and lake plains. Slopes are 0 to 2 percent. Mean annual precipitation is about 150 mm and mean annual temperature is about 10 degrees C.

TAXONOMIC CLASS: Clayey over loamy, smectitic over mixed, superactive, calcareous, mesic Fluvaquentic Endoaquolls

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

Ap--0 to 18 cm; dark gray (N 4/) silt loam, black (N 2/) moist; moderate medium subangular blocky structure that parts to strong very fine granular; hard, friable, moderately sticky and very plastic; many very fine, fine and medium roots; many fine interstitial pores; strongly effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (15 to 20 cm thick)

Ak--18 to 48 cm; very dark gray (10YR 3/1) clay, black (10YR 2/1) moist; few fine faint brown (7.5YR 4/4) iron accumulations and few fine faint black (N 2/) iron depletions; weak medium prismatic structure that parts to moderate medium subangular blocky; very hard, friable, very sticky and very plastic; many very fine, common fine roots, common medium dead roots; common very fine tubular pores; many very fine soft, light gray (2.5Y 7/2) lime threads; strongly effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary. (20 to 40 cm thick)

2Cgk1--48 to 64 cm; light brownish gray (2.5Y 6/2) silt loam, dark grayish brown (2.5Y 4/2) moist; root channels filled with very dark grayish brown (2.5Y 3/2) and black (N 2/) soil material; moderate fine angular blocky structure; very hard, friable, moderately sticky and moderately plastic; many fine and medium roots; many very fine and fine tubular pores; strongly effervescent, few fine filaments; slightly effervescent; strongly alkaline (pH 8.6); abrupt smooth boundary. (13 to 20 cm thick)

2Cgk2--64 to 89 cm; light gray (2.5Y 7/2) silt loam, dark grayish brown (2.5Y 4/2) moist; many fine and medium prominent dark brown (7.5YR 3/4) and brown (7.5YR 4/4) iron accumulations; massive; hard, very friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; many fine and medium pores; common fine nodules and concretions, many fine mollusk shells; violently effervescent; strongly alkaline (pH 8.8); abrupt smooth boundary. (23 to 30 cm thick)

3Cg--89 to 152 cm; light gray (2.5Y 7/2) stratified fine sandy loam to fine sand, dark grayish brown (2.5Y 4/2) moist; common fine and medium prominent brown (7.5YR 4/4) iron accumulations and common fine prominent black (10YR 2/1) organic stains; massive; soft, very friable, nonsticky and nonplastic; few fine roots; many fine tubular pores; many fine and medium very pale brown (10YR 8/2) ostracod shells; violently effervescent; strongly alkaline (pH 8.8).

TYPE LOCATION: Pershing County, Nevada; approximately 6.5 miles south of Lovelock, about 2,000 feet west and 20 feet north of the southeast corner of section 28, T. 26 N., R. 31 E.; latitude 40 degrees 5 minutes 10 seconds N and longitude 118 degrees 30 minutes 5 seconds W; WGS84 Decimal Degrees 40.0861111 latitude, -118.5013889 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually saturated for one month or more during most years unless drained.
Mean annual soil temperature: 12 to 14 degrees C.
Mollic epipedon thickness: 36 to 60 cm.
Depth to discontinuity: 36 to 90 cm.
Effervescence: Slightly effervescent to violently effervescent throughout.
Redox concentration: Distinct or prominent iron redox concentration are present in the lower part of the mollic epipedon or immediately below.
Other features: Small amounts of volcanic ash occurs throughout the profile and some pedons have thin strata of volcanic ash or organic carbon below 50 cm.

Particle-size control section - Clay content: 40 to 55 percent in the upper part and averages 2 to 10 percent in the lower part.
Texture: Clay or silty clay in the upper part and stratified sand to silt loam in the lower part.

A horizon
Hue: N (neutral), 10YR or 2.5Y.
Value: 3 through 5 dry, 2 or 3 moist.
Chroma: 0 or 1.
Reaction: Slightly alkaline through strongly alkaline.
Electrical conductivity (EC): 0 to 32 dS/m.
Sodium absorption ratio (SAR): 0 to 45.
Organic matter: 3 to 6 percent.
Calcium carbonate equivalent: 5 to 10 percent.

Ak horizon
Hue: 10YR or 2.5Y.
Value: 3 through 5 dry, 2 or 3 moist.
Chroma: 0 or 1.
Reaction: Slightly alkaline through strongly alkaline.
Electrical conductivity (EC): 0 to 32 dS/m.
Sodium absorption ratio (SAR): 0 to 45.
Organic matter: 3 to 6 percent.
Calcium carbonate equivalent: 5 to 15 percent.

C horizons
Hue: 2.5Y, 7.5YR, 10YR or N (neutral) redox concentration.
Value: 6 or 7 dry, 4 or 5 moist, 2 through 4 moist, redox concentration.
Chroma: 0 through 4 mottles.
Texture: Stratified with textures ranging from sand to silt loam.
Structure: Weak or moderate, fine or medium angular blocky or subangular blocky in the upper part, or is massive.
Consistence: Soft through hard, dry.
Electrical conductivity (EC): 4 to 8 dS/m.
Sodium absorption ratio (SAR): 13 to 30.
Calcium carbonate equivalent: 5 to 15 percent.
Other features: Few to many ostracod shells and shell fragments are present in any strata.

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

GEOGRAPHIC SETTING: Armydrain soils are on flood plains and lake plains. These soils formed in alluvium derived from mixed rocks and influenced by volcanic ash. Slopes are 0 to 2 percent and are generally less than one percent. Elevations are 1,185 to 1,295 meters. The climate is cool, arid with cool, moist winters and warm, dry summers. Mean annual precipitation is 100 to 200 mm; mean annual air temperature is 9 to 11 degrees C., and the frost-free season is 120 to 140 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bigmeadow, Brinker, Humboldt, Kniesley, Lovelock and Ryepatch series. Bigmeadow, Brinker, Humboldt, Lovelock and Ryepatch soils are fine or very fine textured throughout the particle-size control section. Kniesley soils are loamy over clayey in the particle-size control section.

DRAINAGE AND PERMEABILITY: Poorly drained; ponded or very slow runoff; slow permeability; moderately low saturated hydraulic conductivity in the upper part and moderately rapid permeability; high saturated hydraulic conductivity in the lower part. The water table under natural conditions range from 15 to 50 cm below the surface. Drainage ditches have been constructed and the water table is at 90 to 150 cm during the irrigation season.

USE AND VEGETATION: Most of the area has been leveled and is used for small grains and alfalfa. Areas that are strongly saline are used for native meadow, rangeland and wildlife habitat. The present vegetation is inland saltgrass, basin wildrye and black greasewood.

DISTRIBUTION AND EXTENT: North central Nevada. MLRA 27. These soils are not extensive.

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

SERIES ESTABLISHED: Pershing County (Lovelock Area), Nevada, 1985.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the surface to about 48 cm (Ap and Ak horizons).
Particle-size control section - The zone from 25 to 100 cm (2Cgk1, 2Cgk2 horizons and parts of the Ak and 3Cg horizons).

Classification changed in 1992 from Haplaquolls to Endoaquolls.

National Cooperative Soil Survey
U.S.A.