LOCATION COIT                    NV

Established Series
Rev. RPZ/GJS/JBF
02/2016

COIT SERIES

The Coit series consists of very deep, poorly drained soils that formed in alluvium derived from mixed rock sources. Coit soils are on flood plains. Slopes are 0 to l percent. The mean annual precipitation is about 180 cm and the mean annual temperature is about 9 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Cumulic Endoaquolls

TYPICAL PEDON: Coit loam - rangeland. (Colors are for dry soils unless otherwise noted.)

A1--0 to 5 cm; gray (10YR 5/1) loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine, and few fine roots; many very fine interstitial, and common very fine, and few fine tubular pores; slightly effervescent; slightly alkaline (pH 7.8); abrupt smooth boundary. (3 to 10 cm thick)

A2--5 to 25 cm; grayish brown (10YR 5/2) loam, very dark gray (10YR 3/1) moist; weak coarse prismatic structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots; many very fine interstitial, and common very fine tubular pores; strongly effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (13 to 25 cm thick)

A3--25 to 46 cm; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine interstitial pores; violently effervescent; moderately alkaline (pH 8.4); gradual smooth boundary. (15 to 38 cm thick)

A4--46 to 97 cm; grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist, with few medium faint very dark brown (10YR 2/2) redox concentrations, moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; few very fine tubular and interstitial pores; slightly effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (25 to 50 cm thick)

A5--97 to 152 cm; gray (10YR 5/1) fine sandy loam, very dark grayish brown (10YR 3/2) moist, with common faint very dark brown (10YR 2/2) redox concentrations, moist; massive; hard, friable, slightly sticky and plastic; few very fine, fine and medium roots; few very fine interstitial pores; slightly effervescent; slightly alkaline (pH 7.8).

TYPE LOCATION: Eureka County, Nevada. Approximately 600 feet south and 900 feet west of the apparent northeast corner of Section 11, T. 31 N., R. 49 E.; USGS Beowawe 7.5 minute topographic quadrangle; latitude 40 degrees 34 minutes 49 seconds N and longitude 116 degrees 24 minutes 34 seconds W; WGS84 Decimal Degrees 40.5802778 latitude, -116.4094444 longitude.

RANGE IN CHARACTERISTICS:

Soil moisture: Moist with a high water table in the winter and spring months but are dry continuously between the depths of 13 and 38 cm in the late summer and fall of most years.
Mean annual soil temperature: 49 to 5l degrees F.
Thickness of the mollic epipedon: 50 to more than 150 cm.
Hues: l0YR or 2.5Y.
Other features: C horizons maybe present below 50 cm in some pedons. A few very hard carbonate concretions are below 90 cm in some pedons. Some areas are salt and alkali affected.

Particle-size control section - Clay content: 20 to 30 percent.
Averages loam, silt loam or light clay loam and contains more than l5 percent sand coarser than very fine sand.
Rock fragments: Less than 5 percent.

A1 horizon
Values: 4 or 5 dry and 2 or 3 moist.
Chroma: 1 or 2.
Structure: Weak or moderate, very fine to medium, granular or subangular blocky or weak, medium or coarse prismatic, or is massive.
Effervescence: Slightly effervescent to violently effervescent.
Calcium carbonate equivalent: 1 to 5 percent.
Organic matter: 1 to 2 percent.

A2, A3 and A4 horizons
Values: 4 or 5 dry and 2 or 3 moist.
Chroma: 1 or 2.
Structure: Weak or moderate, very fine to medium, granular or subangular blocky or weak, medium or coarse prismatic, or is massive.
Texture: Strata of loam, silt loam, clay loam, silty clay loam, very fine sandy loam, fine sandy loam or sandy loam. A few thin strata of silty clay or clay, or loamy sand or sand are in some pedons.
Effervescence: Slightly effervescent to violently effervescent.
Calcium carbonate equivalent: 1 to 5 percent.
Organic matter: 1 to 2 percent.

A5 horizon
Values of 4 to 5 dry and 3 or 4 moist.
Chroma: 1 to 3.
Texture: Fine sandy loam to loamy sand
Clay content: 10 to 20 percent.
Calcium carbonate equivalent: 1 to 2 percent.

COMPETING SERIES: These are the Ardtander, Coland, Comfrey, Delft, Excello, Gielow, Glencoe, Gus, James Canyon, Keddie, Kimmerling, Konner, Lundlake, McClave, Peoh, Romnell, Roundval, Shandep and Wenas series.

Ardtander, Coland, Comfrey, Delft, Excello, Gielow, Glencoe, Keddie, Kimmerling, Konner, Lundlake, McClave, Peoh, Romnell, Roundval, Shandep, and Wenas soils lack carbonates in some part of the A horizon. Gus soils receive 410 to 580 mm of mean annual precipitation. James Canyon soils have 15 to 35 percent rock fragments in the particle-size control section.

GEOGRAPHIC SETTING: The Coit soils are on flood plains at elevations of 1,340 to 1,460 meters. Slopes are 0 to 1 percent. The soils formed in alluvium derived from mixed rock sources. The climate is cool and semi-arid. The mean annual precipitation is 150 to 200 mm; mean annual temperature is 8 to 9 degrees C.; and the frost-free season is l00 to l20 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Humboldt, Ocala and Rose Creek soils. Humbolt soils have fine textured particle-size control sections. Ocala soils have fine-silty particle-size control sections and ochric epipedons. Rose Creek soils have coarse-loamy particle-size control sections.

DRAINAGE AND PERMEABILITY: Poorly drained, very slow runoff; moderate permeability; moderately high saturated hydraulic conductivity. Endosaturation is present with an apparent seasonal water table at 46 to 61 cm during the March to June, and is lowest during summer and fall months when it may drop to a depth of 150 to 180 cm. Some areas have been partially drained by entrenchment of stream channels. Overflow commonly occurs on an average of 1 in every 4 to 5 years for brief periods between February and May.

USE AND VEGETATION: Rangeland and wildlife habitat with small areas irrigated and native grasses cut for meadow hay. The vegetation is mainly creeping wildrye with some saltgrass in the saline and alkali affected areas. Drained areas support big sagebrush.

DISTRIBUTION AND EXTENT: North-central Nevada. Soils of this series are of small extent. MLRA 24 and 25.

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

SERIES ESTABLISHED: Eureka County, (Tuscarora Mountain Area), Nevada, l979.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 152 cm (A1, A2, A3, A4 and A5 horizons).
Aquic conditions - The conditions of endosaturation and reduction in horizons between 46 and 152 cm at certain times in normal years (A4 and A5 horizons).
Particle size control section - The zone from 25 to 100 cm (A3 and A4 horizon and part of the A5 horizon).

The revision of 4/2009 changed the classification from Haploxerolls to Endoaquolls. The requirement assumed to be met for aquolls is a positive reaction to alpha-alpha-dipyridyl between 40 and 50 cm.

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National Cooperative Soil Survey
U.S.A.