LOCATION SETTLEMENT              NV

Established Series
Rev. JBF/WED/JVC
05/2016

SETTLEMENT SERIES

The Settlement series consists of very deep, poorly drained soils that formed in alluvium derived from mixed rocks. Settlement soils are on lake plains, lake terraces, and stream terraces. Slopes are 0 to 4 percent. The mean annual precipitation is about 125 mm and the mean annual temperature is about 12 degrees C.

TAXONOMIC CLASS: Fine, smectitic, calcareous, mesic Aeric Halaquepts

TYPICAL PEDON: Settlement silty clay loam--rangeland. (Colors are for dry soil unless otherwise noted.)

A--0 to 10 cm; very pale brown (10YR 8/3) silty clay loam, brown (10YR 5/3) moist; weak thin platy structure; slightly hard, very friable, moderately sticky and moderately plastic; few very fine roots; many fine vesicular pores; violently effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (3 to 18 cm thick)

Bw--10 to 15 cm; very pale brown (10YR 8/3) clay, brown (10YR 5/3) moist; strong very fine and fine subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; few very fine roots; few very fine tubular pores; violently effervescent; very strongly alkaline (pH 9.2); abrupt smooth boundary. (0 to 23 cm thick)

Bk1--15 to 30 cm; very pale brown (10YR 7/3) clay, yellowish brown (10YR 5/4) moist; strong fine angular blocky structure; hard, friable, very sticky and very plastic; few very fine, fine, medium and coarse roots; common very fine tubular pores; many large carbonate nodules and soft masses; violently effervescent; strongly alkaline (pH 8.9); clear smooth boundary. (0 to 20 cm thick)

Bk2--30 to 61 cm; very pale brown (10YR 7/3) clay, brown (10YR 5/3) moist; weak coarse prismatic structure; hard, firm, very sticky and very plastic; few very fine, fine and medium roots; few fine tubular pores; few fine prominent black (10YR 2/1) masses of manganese accumulation on faces of peds; few large carbonate nodules and soft masses; violently effervescent; strongly alkaline (pH 8.6); clear irregular boundary. (25 to 43 cm thick)

Bk3--61 to 152 cm; very pale brown (10YR 7/3) silty clay, brown (10YR 5/3) moist; weak coarse prismatic structure; hard, firm, very sticky and very plastic; few fine and medium tubular pores; common fine prominent black (10YR 2/1) masses of manganese accumulation on faces of peds; many fine carbonate nodules and soft masses; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary.

TYPE LOCATION: Churchill County, Nevada; about 40 miles east-northeast of Fallon in the Dixie Valley; 2,000 feet north and 2,600 feet west of the southeast corner of section 7, T.21N., R.35E; USGS Dixie Valley 7.5 minute topographic quadrangle; latitude 39 degrees 42 minutes 00 seconds N and longitude 118 degrees 5 minutes 22 seconds W; WGS84 Decimal Degrees 39.6995556 latitude, -118.089444 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Saturated at or near the surface in late winter and early spring, usually dry in summer and fall. The water table fluctuates between 30 and 90 cm in February through May and drops below 152 cm in August through November.
Mean Annual soil temperature: 12 to 15 degrees C.
Depth to identifiable secondary carbonates: 13 to 41 cm.
Effervescence: Slightly effervescent through violently effervescent.
Calcium carbonate equivalent: 10 to 20 percent.
Gypsum content: 0 to 4 percent.
Other features: Buried A horizons and C horizons are in the lower part of some pedons

Particle-size control section - Clay content: Averages 45 to 65 percent;

A horizon
Value: 6 through 8 dry, 5 or 6 moist.
Chroma: 2 through 4.
Structure: Weak or moderate platy or subangular blocky.
Consistence: Slightly hard or hard, dry; very friable through firm, moist.
Reaction: Moderately alkaline or strongly alkaline.

Bw horizon
Hue: 10YR or 7.5YR.
Value: 5 through 8 dry, 4 through 6 moist.
Chroma: 2 through 4.
Texture: Clay or silty clay; subhorizons of silty clay loam are in some pedons.
Structure: Weak to strong subangular blocky or prismatic.
Reaction: Strongly alkaline or very strongly alkaline.
Salinity (EC): 8 to 16 mmhos/cm.
Sodicity (SAR): 13 to 30.

Bk horizons
Hue: 10YR or 7.5YR.
Value: 5 through dry, 4 through moist.
Chroma: 3 or 4.
Texture: Clay or silty clay; subhorizons of silty clay loam are in some pedons.
Structure: Subangular blocky or prismatic, some Bk horizons are massive.
Reaction: Moderately alkaline to very strongly alkaline.
Salinity (EC): 8 to 16 mmhos/cm in the upper part, 4 to 8 mmhos/cm in the lower part.
Sodicity (SAR): 13 to 30 in the upper part, 5 to 12 in the lower part.
Redoximorphic features: Redox concentrations are present in few or common masses of iron or manganese accumulation.

COMPETING SERIES: These are the Boravall, Longmont, and Umberland series.

Boravall soils have mean annual soil temperatures of 8 to 10 degrees C. and have 35 to 45 percent clay in the series control section. Longmont soils are moist in the summer and fall and have accumulations of secondary gypsum in the C horizon. Umberland soils have mean annual soil temperature of 8 to 11 degrees C. and have hue of 2.5Y or 5Y.

GEOGRAPHIC SETTING: Settlement soils are on lake plains, lake terraces, and stream terraces. They formed in alluvium derived from mixed rocks. Slopes are 0 to 4 percent. Elevations range from 1,035 to 1,590 meters. The climate is cool-arid with cool, moist winters and hot, dry summers. The mean annual precipitation is 100 to 200 mm, the mean annual temperature is 11 to 14 degrees C., and the frost-free period is 120 to 160 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Louderback, Rustigate, and Slaw soils. Louderback soils are sandy and somewhat poorly drained. Rustigate soils are fine-loamy and somewhat poorly drained. Slaw soils are fine-silty, well drained, and are highly stratified.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Poorly drained; very low or low surface runoff; low saturated hydraulic conductivity. These soils have a rare flooding frequency. A seasonal high water table is present between 30 and 90 cm (shallow or moderately deep free water occurrence class) for some time during the year. Cumulative annual duration class is Common (February through May).

USE AND VEGETATION: Settlement soils are used for rangeland with limited use for urban development and irrigated cropland. The vegetation in rangeland is mainly black greasewood, rubber rabbitbrush, seepweed, basin big sagebrush, inland saltgrass, alkali sacaton, and basin wildrye.

DISTRIBUTION AND EXTENT: Western Nevada. These soils are not extensive. MLRAs 27 and 29.

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

SERIES ESTABLISHED: Esmeralda County Area, Nevada, 1984.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 18 cm (A, Bw horizons and part of the Bk1 horizons).
Endosaturation feature - The condition of ground water with an upper boundary between 30 and 90 cm for some time during normal years.
Aeric subgroup feature - Chroma of 3 or 4 in some subhorizon between 15 and 76 cm (Bk1, Bk2, and Bk3 horizons).
Particle-size control section - The zone from 25 to 100 cm (Bk2 horizon, part of the Bk1 and Bk3 horizons).

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National Cooperative Soil Survey
U.S.A.