LOCATION NILESVAL                NV

Established Series
REV: DJM/LJL/CAH
12/2015

NILESVAL SERIES

The Nilesval series consists of very deep, well drained soils that formed in alluvium derived from limestone. Nilesval soils are on inset fans. Slope ranges from 2 to 8 percent. The mean annual precipitation is about 295 millimeters and the mean annual air temperature is about 11 degrees C.

TAXONOMIC CLASS: Coarse-loamy, carbonatic, mesic Ustic Haplocambids

TYPICAL PEDON: Nilesval gravelly sandy loam, rangeland and wildlife habitat. (Colors are for dry soil unless otherwise noted.) The soil surface is covered by approximately 2 percent fine gravel, 13 percent medium and coarse gravel and 3 percent cryptograms.

A--0 to 8 centimeters (0 to 3 inches); brown (10YR 5/3), gravelly sandy loam, dark grayish brown (10YR 4/2) moist; strong thick platy structure; slightly hard, very friable, nonsticky and nonplastic; common very fine roots; many very fine and common fine vesicular pores; 2 percent fine gravel, 13 percent medium and coarse gravel; violently effervescent (40 percent calcium carbonate equivalent in the fine earth fraction); moderately alkaline (pH 8.0); clear smooth boundary. (5 to 10 centimeters thick)

Bw--8 to 18 centimeters (3 to 7 inches); brown (10YR 5/3), fine sandy loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and slightly plastic; many very fine and fine roots; many very fine and fine interstitial and common fine tubular pores; 1 percent fine gravel, 9 percent medium and coarse gravel; violently effervescent (40 percent calcium carbonate equivalent in the fine earth fraction); moderately alkaline (pH 8.2); gradual smooth boundary. (0 to 12 centimeters thick)

Bk1--18 to 52 centimeters (7 to 20 inches); brown (10YR 5/3), gravelly sandy loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, very friable, nonsticky and slightly plastic; many very fine and fine , few medium and common coarse roots; many very fine and common fine tubular pores; 30 percent prominent, white (10YR 8/1), calcium carbonate coats on bottom surfaces of rock fragments; 5 percent fine gravel, 15 percent medium and coarse gravel; violently effervescent (45 percent calcium carbonate equivalent in the fine earth fraction); moderately alkaline (pH 7.9); clear wavy boundary.

Bk2--52 to 80 centimeters (20 to 31 inches); brown (10YR 5/3), fine sandy loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and few fine roots; many very fine and fine tubular and many very fine interstitial pores; 35 percent prominent, white (10YR 8/1), calcium carbonate coats on bottom surfaces of rock fragments; 4 percent medium, distinct, very pale brown (10YR 8/2), calcium carbonate masses, irregular, noncemented, with sharp boundary; 1 percent fine gravel, 4 percent medium and coarse gravel; violently effervescent (45 percent calcium carbonate equivalent in the fine earth fraction); moderately alkaline (pH 7.9); abrupt wavy boundary. (The combined thickness of the Bk horizons is 30 to 75 centimeters.)

2Bk1--80 to 105 centimeters (31 to 41 inches); brown (10YR 5/3), extremely gravelly loamy sand, brown (10YR 4/3) moist; massive; slightly hard, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine interstitial and few fine tubular pores; 35 percent prominent, white (10YR 8/1), calcium carbonate coats on bottom surfaces of rock fragments; 4 percent medium, distinct, very pale brown (10YR 8/2), calcium carbonate masses, irregular, noncemented, with sharp boundary; 3 percent fine gravel, 57 percent medium and coarse gravel; violently effervescent (55 percent calcium carbonate equivalent in the fine earth fraction); moderately alkaline (pH 8.0); clear wavy boundary.

2Bk2--105 to 152 centimeters (41 to 60 inches); yellowish brown (10YR 5/4), extremely gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; massive; soft, very friable, nonsticky and slightly plastic; common very fine roots; many very fine and fine interstitial pores; 35 percent prominent, white (10YR 8/1), calcium carbonate coats on bottom surfaces of rock fragments; 25 percent fine gravel, 40 percent medium and coarse gravel; violently effervescent (55 percent calcium carbonate equivalent in the fine earth fraction); moderately alkaline (pH 8.1). (The combined thickness of the 2Bk horizons is 65 to 85 centimeters.)

TYPE LOCATION: Clark County, Nevada; about 13 kilometers north and 23 kilometers east of Corn Creek, Nevada at the north end of Peekaboo Canyon; approximately 10 kilometers south-southwest of Wamp Spring; 480 feet north and 1050 feet west of the southeast corner of section 12, T. 16 S., R. 61 E.; USGS Hayford Peak SE, NV 7.5 minute topographic quadrangle; 36 degrees, 33 minutes, 2.2 seconds north latitude and 115 degrees, 5 minutes, 57.2 seconds west longitude; UTM 11S 0670124e 4046703n (DATUM: NAD83).

RANGE IN CHARACTERISTICS: Soil moisture control section: Usually dry, moist in late winter and early spring and intermittently moist in the upper part following summer convection storms; aridic soil moisture regime bordering on ustic.

Soil temperature: 10 to 14 degrees C.

Calcium carbonate equivalence of the less than 2 millimeter fraction: 40 to 60 percent.

Control section -

Depth to upper boundary of cambic horizon: 5 to 10 centimeters.
Rock fragments: averages 5 to 35 percent, mainly gravel. Upper part averages 5 to 25 percent and the lower part ranges 35 to 65 percent.
Clay content: 6 to 12 percent.

A horizon
Value: 4 or 5 dry, 3 or 4 moist.
Chroma: 2 or 3, dry.

Bw horizon (when present)
Texture: fine sandy loam or loam.
Consistence: soft or very friable, nonsticky or slightly sticky, nonplastic or slightly plastic.
Rock fragments: averages 5 to 10 percent.
Sodium Adsorption Ratio: 0.20 to 0.40.
Electrical conductivity: 2.0 to 3.8 dS/m.

Bk horizons
Texture: fine sandy loam, sandy loam or loam.
Structure: weak through strong.
Consistence: soft or very friable, nonsticky or slightly sticky, nonplastic or slightly plastic.
Rock fragments: averages 15 to 25 percent, ranges 5 to 35 percent gravel.
Sodium Adsorption Ratio: 0.20 to 0.50.
Electrical conductivity: 2.0 to 3.8 dS/m.

2Bk horizons
Texture: fine sandy loam, sandy loam or loam.
Structure: massive or weak subangular blocky.
Consistence: soft or very friable, nonsticky or slightly sticky, nonplastic or slightly plastic.
Rock fragments: ranges 35 to 65 percent gravel.
Sodium Adsorption Ratio: 0.40 to 0.50.
Electrical conductivity: 2.0 to 4.2 dS/m.

COMPETING SERIES: There are no competing series at this time.

GEOGRAPHIC SETTING: Nilesval soils are on inset fans. Slope ranges from 2 to 8 percent. These soils formed in alluvium derived from limestone. Elevations are 1,790 to 1,980 meters (5,870 to 6,500 feet). The climate is semiarid with cool, moist winters and warm, intermittently moist summers. Precipitation is greatest in the winter with lesser secondary peak in the summer, typical of the Mojave Desert transitional to Great Basin. The mean annual precipitation is 260 to 330 millimeters; mean annual air temperature is 8 to 12 degrees C., and the frost-free season is 90 to 135 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are Boxspring and Wamp soils. Wamp soils occur on fan remnants and have shallow, strongly cemented to indurated petrocalcic horizons. Boxspring soils are shallow to a lithic contact of limestone bedrock.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; low runoff; high saturated hydraulic conductivity.

USE AND VEGETATION: These soils are used for rangeland and wildlife habitat. The present vegetation is mainly fourwing saltbush, mountain big sagebrush, winterfat, threadleaf snakeweed, needle and thread, Indian ricegrass, blue grama and squirreltail.

DISTRIBUTION AND EXTENT: Mojave Desert of southern Nevada, U.S.A.; MLRA 30. These soils are not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: PHOENIX, ARIZONA

SERIES ESTABLISHED: Desert National Wildlife Refuge Area, Nevada, South Part; Clark County, Nevada 2011. The name is coined from the common use name, Niles Valley, where the proposed series is located.

REMARKS: Diagnostic horizons and features recognized in the profile are:

Ochric epipedon - 0 to 18 centimeters (0 to 7 inches) (A and Bw horizons).
Cambic horizon - 8 to 80 centimeters (3 to 31 inches) (Bw, Bk1 and Bk2).
Particle-size control section - 25 to 100 centimeters (10 to 40 inches) (Part of the Bk1, Bk2 and part of the 2Bk1 horizons).

Responsibility for this series was transferred from Davis to Phoenix 12/2015. The last revision to the series was 6/2011. ET

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National Cooperative Soil Survey
U.S.A.