LOCATION THACKER                 ID

Established Series
Rev. AM/ALH/CLM
12/2019

THACKER SERIES


The Thacker series consists of moderately deep to a duripan, well drained soils that formed in mixed alluvium. Thacker soils are on piedmonts, fan terraces and alluvial terraces and have slopes of 1 to 12 percent. Permeability is very slow. The average annual precipitation is about 380 mm, and the average annual temperature is about 7.2 degrees C.

TAXONOMIC CLASS: Fine, smectitic, frigid Abruptic Durixeralfs

TYPICAL PEDON: Thacker loam -- on a 2 percent southwest-facing slope at an elevation of 1,630 meters in native rangeland. (When described on October 2, 1981, the soil was moist throughout. Colors are for air dry soil unless otherwise noted.)

E1--0 to 10 cm; pale brown (10YR 6/3) loam, dark grayish brown (10YR 4/2) moist; moderate thin platy structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine, fine and medium roots; many fine and medium vesicular pores; neutral (pH 6.6); clear smooth boundary. (8 to 20 cm thick)

E2--10 to 30 cm; pale brown (10YR 6/3) gravelly loam, dark brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; many very fine and fine interstitial pores; few light gray (10YR 7/2) silt coatings on faces of peds; 15 percent gravel; neutral (pH 6.9); abrupt smooth boundary. (0 to 25 cm thick)

Bt--30 to 53 cm; dark yellowish brown (10YR 4/4) clay, dark yellowish brown (10YR 4/4) moist; strong medium columnar structure; very hard, firm, very sticky and very plastic; common very fine and medium roots; few very fine tubular pores; common distinct clay films on faces of peds and in pores; many pressure faces; columns are capped with light gray (10YR 7/2) silt; neutral (pH 7.3); abrupt wavy boundary. (18 to 51 cm thick)

2Bkqm--53 to 78 cm; light yellowish brown (10YR 6/4) indurated duripan, dark yellowish brown (10YR 4/4) moist; strong medium platy structure; very hard, very firm and brittle moist; few very fine roots between plates; continuous silica coatings (1 mm thick) on surfaces of plates; slightly effervescent, carbonates segregated in few medium seams; common fine dark concretions and stains (Mn oxides); moderately alkaline (pH 8.0); gradual smooth boundary. (13 to 46 cm thick)

2C1--78 to 110 cm; variegated but dominantly light yellowish brown (10YR 6/4) extremely gravelly sand, dark yellowish brown (10YR 4/4) moist; massive; hard, friable, nonsticky and nonplastic; many very fine and fine interstitial pores; moderately alkaline (pH 8.2); gradual smooth boundary. (0 to 33 cm thick)

2C2--110 to 152 cm; variegated stratified layers of gravelly sand and sand, variegated moist; single grain; loose, nonsticky and nonplastic; many very fine and fine interstitial pores; moderately alkaline (pH 7.9).

TYPE LOCATION: Owyhee County, Idaho; about 3 1/2 miles north and 1 mile west of Owyhee, Nevada; 3,150 feet south and 3,500 feet east of the northwest corner of section 29, T. 16 S., R. 3 E.; USGS Mountain View Lake 7.5-minute topographic quadrangle; latitude XX degrees XX minutes XX seconds N and longitude YYY degrees YY minutes YY seconds W; WGS84 Decimal Degrees 42.0025000 latitude, -116.1258333 longitude.

RANGE IN CHARACTERISTICS:

Depth to abrupt textural change - 18 to 38 cm
Depth to duripan - 50 to 100 cm.
Average annual soil temperature - 5.0 to 8.3 degrees C.
Average summer soil temperature - 16.1 to 19.4 degrees C.
Average annual precipitation - 300 to 410 mm. Soil Moisture: This soil is usually moist, but is dry for 45 to 70 consecutive days during the late summer and autumn. Typic xeric moisture regime.

E horizon
Value - 6 or 7 dry, 3 to 5 moist
Chroma - 2 or 3 moist or dry
Reaction - slightly acid or neutral

Bt horizon
Value - 4 to 6 dry, 3 to 5 moist
Chroma - 3 to 6 moist and dry
Clay content - 40 to 60 percent
Coarse fragments - 0 to 10 percent
Reaction - slightly acid through mildly alkaline

2Bkqm horizon
Value - 6 to 8 dry, 3 to 6 moist
Chroma - 3 to 6 moist or dry
Coarse fragments - 0 to 30 percent
Calcium carbonate accumulation - none to common
Other features - C and/or BC horizons may be present in some pedons above the duripan

COMPETING SERIES: There are no competing series listed in the same family. A closely related soil is the Deunah series. Deunah soils have bedrock at 100 cm or less and are in a very fine textural family.

GEOGRAPHIC SETTING: Thacker soils are on nearly level or rolling piedmonts, fan terraces, and alluvial terraces. Slopes range from 1 to 12 percent. Elevation ranges from 1,465 to 2,170 meters. The soil formed in mixed alluvium from extrusive rocks and volcanic ash. The average annual precipitation is 12 to 16 inches, most of which falls as snow and spring rain. The average annual temperature is 3.9 to 7.2 degrees C. The frost-free period is 60 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Simonton, Soonahbe, and Yatahoney soils. Simonton soils lack a duripan. Soonahbe and Yatahoney soils lack an abrupt textural change. Simonton and Soonahbe soils are on convex positions and uneroded surfaces. Yatahoney soils are on similar landscape positions as Thacker soils.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; slow to rapid runoff; very slow saturated hydraulic conductivity.

USE AND VEGETATION: Thacker soils are used mainly for rangeland and wildlife habitat with small areas cropped to alfalfa hay and barley. Dominant natural vegetation is low sagebrush, Idaho fescue, bluebunch wheatgrass, and Hooker balsamroot.

DISTRIBUTION AND EXTENT: Southwestern Idaho and north-central Nevada. The soils of this series are moderately extensive. MLRA 25.

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

SERIES ESTABLISHED: Owyhee County, Idaho; Duck Valley Indian Reservation, Idaho-Nevada, 1984.

REMARKS: Diagnostic horizons and other features recognized in this pedon:

Ochric epipedon - The zone from 0 to 30 cm (The E1 and E2 horizons).
Abrupt textural change - At 30 cm, greater than 15 percent clay increase within 1 inch (The upper boundary of Bt horizon)
Argillic horizon and particle-size control section - The zone from 30 to 53 cm (The Bt horizon).

Duripan - The zone 53 to 78 cm (The Bkqm horizon).


National Cooperative Soil Survey
U.S.A.