LOCATION SHAFTER NV

Established Series
Rev. JVC/JBF
12/2011

SHAFTER SERIES

The Shafter series consists of shallow to a petrocalcic horizon, well drained soils that formed in alluvium derived from limestone and dolostone with some loess and volcanic ash. Shafter soils are on fan remnants. Slopes are 2 to 8 percent. The mean annual precipitation is about 180 mm and the mean annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Loamy, mixed, superactive, mesic, shallow Calcic Petrocalcids

TYPICAL PEDON: Shafter gravelly loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered with 20 percent gravel.

A--0 to 8 cm; light yellowish brown (10YR 6/4) gravelly loam, dark grayish brown (10YR 4/2) moist; moderate thin platy structure; slightly hard, very friable, nonsticky and nonplastic; few very fine roots; many very fine and common fine vesicular pores; 15 percent gravel; violently effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (5 to 15 cm thick)

Bk--8 to 36 cm; light gray (10YR 7/2) gravelly very fine sandy loam, brown (10YR 5/3) moist; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common very fine and many fine roots; many very fine and few fine interstitial pores; 20 percent gravel; secondary carbonates segregated as common pendants on bottoms of rock fragments; violently effervescent; strongly alkaline (pH 8.6); abrupt smooth boundary. (15 to 38 cm thick)

2Bkm--36 to 76 cm; very pale brown (10YR 8/2) cemented material, light yellowish brown (10YR 6/4) moist; massive; very rigid; indurated by secondary carbonates with a minor amount of accessory silica; violently effervescent; abrupt wavy boundary. (25 to 64 cm thick)

3Ck--76 to 155 cm; very pale brown (10YR 8/2) stratified sandy loam to very gravelly coarse sand, light yellowish brown (10YR 6/4) moist; single grain; loose; nonsticky and nonplastic; alternating lenses and strata of up to 60 percent discontinuous 0.6 to 2.5 cm thick strong cementation by secondary carbonates; averages 55 percent gravel; secondary carbonates segregated as many pendants on bottoms of gravel; violently effervescent; strongly alkaline (pH 8.5).

TYPE LOCATION: Elko County, Nevada; approximately 4 miles east of Montello in Tecoma Valley; about 80 feet south and 450 feet east of the northeast corner of section 24, T. 39 N., R. 69 E.; USGS Tecoma 7.5 minute topographic quadrangle; latitude 41 degrees 15 minutes 22 seconds N and longitude 114 degrees 10 minutes 58 seconds W; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in winter and spring, dry late May through early November; typic aridic soil moisture regime.
Mean annual soil temperature: 12 to 15 degrees C.
Depth to petrocalcic horizon: 25 to 50 cm.
Depth to bedrock: More than 200 cm.
Reaction: Moderately alkaline or strongly alkaline.
Effervescence: Strongly effervescent or violently effervescent.
Calcium carbonate content: Averages 15 to 30 percent for the less than 20 mm fraction above the petrocalcic horizon.

Particle-size control section - Clay content: 8 to 18 percent.
Rock fragments: 15 to 35 percent, mainly gravel. Lithology of fragments are mainly limestone.

A horizon
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 3 or 4 dry, 2 or 3 moist.
Structure: Thin to thick platy.

Bk horizon
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3, dry or moist.
Texture: Gravelly very fine sandy loam, gravelly loam, or gravelly silt loam.
Clay content: 8 to 18 percent.
Rock fragments: 15 to 35 percent, mainly gravel.
Structure: Weak or moderate subangular blocky, or is massive.
Identifiable secondary carbonates: Occurs mainly as pendants on bottoms of rock fragments.
Calcium carbonate equivalent: 10 to 20 percent.

2Bkm horizon
Value: 7 or 8 dry, 6 or 7 moist.
Chroma: 2 through 4, dry or moist.

3Ck horizons
Value: 7 or 8 dry, 5 or 6 moist.
Chroma: 2 through 4, dry or moist.
Texture: Stratified sandy loam to extremely gravelly coarse sand.
Clay content: 0 to 8 percent.
Rock fragments: 45 to 75 percent, mainly gravel.
Cementation class: Weakly to strongly cemented discontinuous (30 to 70 percent) lenses or strata.
Calcium carbonate equivalent: 5 to 15 percent.

COMPETING SERIES: These are the Cardenas, Limeridge, and Pocum series.

Cardenas soils are intermittently moist in summer months following convective storms, have an aridic moisture regime that borders on ustic, and have less than 15 percent rock fragments in the particle-size control section. Limeridge soils are intermittently moist in summer months following convective storms, have hue of 5YR or 2.5YR, and have lithic contacts within 100 cm of the soil surface. Pocum soils are intermittently moist in summer months following convective storms, have an aridic moisture regime that borders on ustic, and have lithic contacts between 100 and 150 cm from the soil surface.

GEOGRAPHIC SETTING: Shafter soils are on fan remnants. These soils formed in alluvium derived from limestone and dolostone with some loess and volcanic ash. Slopes are 2 to 8 percent. Elevations range from 1,465 to 1,590 meters. The climate is arid with cool, moist winters and warm, dry summers. The mean annual precipitation is 150 to 200 mm, mean annual temperature is 8 to 9 degrees C, and the frost-free period is 100 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gravier, Loray, and Smaug soils. Gravier soils are loamy-skeletal and very deep. Loray soils are sandy-skeletal and very deep. Smaug soils are coarse-silty, very deep, and do not have petrocalcic horizons.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; very high surface runoff; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Shafter soils are used for rangeland and wildlife habitat. The present vegetation is mainly winterfat, bluegrass, and Indian ricegrass.

DISTRIBUTION AND EXTENT: Northeastern Nevada. These soils are not extensive with about 2,600 acres of the series mapped to date. MLRA 28A.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona.

SERIES ESTABLISHED: Elko County (Northeast Part), Nevada, 1986.

REMARKS: This revision of December 2002 updates the taxonomic class from Loamy, mixed, mesic, shallow Typic Petrocalcids. The superactive cation exchange activity class was assigned based on soil property data and lab data for adjacent SSL pedons. The Calcic subgroup recognizes the Bk horizon as a calcic horizon.

Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 18 cm (A and part of the Bk horizons).
Calcic horizon - The zone from 8 to 36 cm (Bk horizon).
Petrocalcic horizon - The zone from 36 to 76 cm (2Bkm horizon).
Particle-size control section - The zone from the soil surface to 36 cm (A and Bk horizons).

ADDITIONAL DATA: Previous authors and editors include: HDP-DWW-GJS.

National Cooperative Soil Survey
U.S.A.