LOCATION OTOMO                   NV

Established Series
Rev. WMA/JVC/JBF
11/2016

OTOMO SERIES

The Otomo series consists of very shallow and shallow to a duripan, well drained soils that formed in alluvium derived from mixed rocks. Otomo soils are on fan remnants. Slopes are 4 to 15 percent. The mean annual precipitation is about 150 mm and the mean annual temperature is about 10 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic, shallow Typic Haplodurids

TYPICAL PEDON: Otomo gravelly sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 3 cm; light brownish gray (10YR 6/2) gravelly sandy loam, dark grayish brown (10YR 4/2) moist; weak thin platy structure; slightly hard, very friable, nonsticky and nonplastic; many fine vesicular pores; 25 percent gravel; slightly effervescent; strongly alkaline (pH 8.6); abrupt smooth boundary. (3 to 8 cm thick)

A2--3 to 10 cm; light yellowish brown (10YR 6/4) gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; few medium and common fine and many very fine roots; many fine and very fine tubular pores; 25 percent gravel; strongly effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (5 to 23 cm thick)

Bqk--10 to 25 cm; very pale brown (10YR 7/3) very gravelly sandy loam, brown (10YR 5/3) moist; massive; soft, very friable, nonsticky and nonplastic; many medium, fine and very fine roots; many very fine interstitial pores; 30 percent hard durinodes; 45 percent gravel; few medium carbonate coats on rock fragments; strongly effervescent; strongly alkaline (pH 8.6); abrupt wavy boundary. (10 to 20 cm thick)

Bqkm--25 to 58 cm; very pale brown (10YR 8/2) and pale brown (10YR 6/3) indurated duripan, pale brown (10YR 6/3) moist with dark yellowish brown (10YR 4/4) laminae of silica; massive; extremely hard; violently effervescent; strongly alkaline (pH 8.8); gradual wavy boundary. (20 to 46 cm thick)

B'qk--58 to 152 cm; light gray (10YR 7/2) extremely gravelly loamy sand, grayish brown (10YR 5/2) moist; single grain; loose, nonsticky and nonplastic; many very fine interstitial pores; 20 percent hard durinodes; 65 percent gravel; common fine and medium carbonate coats on rock fragments; violently effervescent; very strongly alkaline (pH 9.6)

TYPE LOCATION: Lyon County, Nevada; about 8 miles southwest of Yerington; about 800 feet north and 100 feet east of the southwest corner of section 30, T. 12 N., R. 25 E.; USGS Wilson Canyon 7.5 minute topographic quadrangle; latitude 38 degrees 52 minutes 10 seconds N and longitude 119 degrees 14 minutes 9 seconds W; WGS84 Decimal Degrees 38.8694444 latitude, - 119.2358333 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture - Moist in the winter and spring, dry in summer and fall; typic aridic moisture regime.
Mean annual soil temperature - 11 to 12 degrees C.
Depth to indurated duripan - 15 to 36 cm.

Particle-size control section - Clay content: 5 to 18 percent.
Rock fragments: 35 to 60 percent, lithology of fragments is mixed.

A horizon
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 1 through 4.
Reaction: Moderately alkaline through very strongly alkaline.
Effervescence: Noneffervescent to violently effervescent.


Bqk horizonValue: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 to 4.
Rock fragments: 35 to 60 percent.
Reaction: Strongly alkaline or very strongly alkaline.
Salinity (EC): 0 to 4 mmhos/cm.
Sodicity (SAR): 5 to 30.
Calcium carbonate equivalent: 1 to 5 percent.

B'qk horizon
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 to 4.
Texture: very gravelly loamy sand, extremely gravelly loamy sand, or extremely gravelly sandy loam.
Rock fragments: 35 to 80 percent.
Reaction: Strongly alkaline or very strongly alkaline.
Calcium carbonate equivalent: 1 to 5 percent.

COMPETING SERIES: These are the Osobb, Osoll, Pahroc and Treadwell series.

Osobb soils have hard bedrock underlying the duripan at 23 and 50 cm. Osoll soils have hard bedrock underlying the duripan at 50 to 100 cm. Pahroc soils have mean annual soil temperature of 12 to 15 degrees C., are intermittently moist in the moisture control section for 5 to 10 days cumulative between July and September, and have duripans 46 to 90 cm thick over subhorizons dominated by coarse sand. Treadwell soils are intermittently moist for 10 to 20 days cumulative from July through September due to convection storms

GEOGRAPHIC SETTING: Otomo soils are on fan remnants. They formed in alluvium derived from mixed rocks. Slopes are 4 to 15 percent. Elevations range from 1,370 to 1,770 meters. The mean annual precipitation is 100 to 200 mm, the mean annual temperature is 9 to 11 degrees C., and the frost-free period is 100 to 140 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cleaver, Malpais, and Perazzo soils. Cleaver soils are loamy, shallow to duripans, and have argillic horizons. Malpais soils are loamy-skeletal, very deep, have cambic horizons, and do not have duripans. Perazzo soils are loamy-skeletal, very deep, have argillic horizons, and do not have duripans.

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

USE AND VEGETATION: Otomo soils are used for livestock grazing and wildlife habitat. The vegetation is mainly Indian ricegrass, Bailey greasewood, shadscale, bud sagebrush, and bottlebrush squirreltail.

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

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

SERIES ESTABLISHED: Lyon County Area, Nevada, 1981.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 18 cm (A1, A2 and part of the Bqk horizons).
Indurated duripan - The zone from 25 to 58 cm (Bqkm horizon).
Particle-size control section - The zone from the soil surface to 25 cm (A1, A2, and Bqk horizons).

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National Cooperative Soil Survey
U.S.A.