LOCATION TAGUM                   NV

Established Series
Rev. EWB-TM-JVC-JBF
06/2017

TAGUM SERIES

The Tagum series consists of moderately deep, well drained soils that formed in colluvium and residuum derived from granitic rock. Tagum soils are on mountains. Slopes are 15 to 50 percent. The mean annual precipitation is about 460 mm and the mean annual temperature is about 4 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Xeric Argicryolls

TYPICAL PEDON: Tagum very gravelly coarse sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is covered with about 10 percent stones, 10 percent cobbles, and 45 percent gravel.

A1--0 to 5 cm; grayish brown (10YR 5/2) very gravelly coarse sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine roots, common very fine interstitial pores; 5 percent stones, 5 percent cobbles, and 45 percent gravel; neutral (pH 6.8); clear wavy boundary. (5 to 10 cm thick)

A2--5 to 13 cm; brown (10YR 5/3) very gravelly coarse sandy loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and common fine roots; common very fine tubular and interstitial pores; 5 percent cobbles and 50 percent gravel; neutral (pH 6.6); clear wavy boundary. (5 to 10 cm thick)

Bt1--13 to 25 cm; brown (10YR 5/3) very gravelly coarse sandy loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; slightly hard, very friable, slightly sticky and nonplastic; common very fine and fine roots; common very fine tubular and interstitial pores; few faint clay bridges between sand grains; 50 percent gravel; neutral (pH 6.8); clear wavy boundary. (10 to 25 cm thick)

Bt2--25 to 36 cm; light yellowish brown (10YR 6/4) very gravelly sandy clay loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; hard, very friable, moderately sticky and slightly plastic; common very fine and fine roots; common very fine tubular and interstitial pores; common distinct clay films on faces of peds; 50 percent gravel; neutral (pH 6.8); clear wavy boundary. (10 to 25 cm thick)

Bt3--36 to 53 cm; reddish brown (5YR 5/4) very gravelly sandy clay loam, reddish brown (5YR 4/4) moist; massive; very hard, friable, moderately sticky and slightly plastic; few very fine roots; common very fine tubular and interstitial pores; common distinct clay films lining pores and few clay bridges between sand grains; 50 percent gravel; neutral (pH 6.8); clear wavy boundary. (15 to 23 cm thick)

Bt4--53 to 76 cm; reddish brown (5YR 5/4) very gravelly sandy clay loam, reddish brown (5YR 4/4) moist; massive; very hard, friable, slightly sticky and slightly plastic; few very fine roots; common very fine tubular and interstitial pores; common distinct clay films lining pores; 50 percent gravel; neutral (pH 6.8); gradual wavy boundary. (0 to 25 cm thick)

Cr--76 to 102 cm; highly weathered granitic rock with soil and few roots in fractures.

TYPE LOCATION: Douglas County, Nevada; in the Pine Nut Mountains south of the summit of Mount Siegel; about 1,600 feet north and 2,200 feet east of the southwest corner of section 22, T. 12 N., R. 22 E.; USGS Mount Siegel 7.5 minute topographic quadrangle; latitude 38 degrees 53 minutes 11 seconds N and longitude 119 degrees 30 minutes 09 seconds W; WGS84 Decimal Degrees 38.8862833 latitude, -119.5023667 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Moist in the moisture control section in winter and spring, dry in summer through mid-fall; The moisture distribution is such that it limits the depth of wetting to about 38 to 50 cm in most years; xeric soil moisture regime that borders on aridic.
Mean annual soil temperature: 6 to 7 degrees C.
Mean summer soil temperature: 12 to 15 degrees C.
Mollic epipedon thickness: 25 to 38 cm, includes the Bt1 horizon.
Depth to base of argillic horizon; 50 to 100 cm.
Depth to bedrock: 50 to 100 cm to a paralithic contact. The paralithic materials below the contact are weathered granitic rock.
Reaction; Slightly acid or neutral.

Particle-size control section - Clay content: 18 to 25 percent.
Sand content: 50 to 65 percent, fractions are mainly coarse sand and very coarse sand.
Rock fragments: 35 to 50 percent, mostly fine (2 to 5 mm. diameter) gravel with 0 to 10 percent cobbles and 0 to 10 percent stones. Lithology of fragments is granitic rocks such as granodiorite.

A1 horizon
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.

A2 horizon
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Clay content: 10 to 15 percent.
Organic matter content: 1 to 3 percent.

Bt1 horizon
Hue: 5YR through 10YR.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4, dry or moist.
Clay content: 18 to 20 percent.
Rock fragments: 35 to 50 percent, mainly 2 to 5 mm. diameter gravel.
Consistence: Slightly hard to very hard.
Organic matter content: 1 or 2 percent.

Bt2, Bt3, and Bt4 horizons
Hue: 5YR through 10YR.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4, dry or moist.
Clay content: 20 to 25 percent.
Rock fragments: 35 to 50 percent, mostly 2 to 5 mm. diameter gravel.
Structure: Subangular blocky in the Bt2 horizon, the Bt3 and Bt4 horizons are massive in some pedons.
Consistence: Slightly hard to very hard.

COMPETING SERIES: These are the Boneyard, Chamberlain, Cowlow, Crandall, Forsey, Fourme, Itwo, Jackflat, Packer, Scuffe, Stopatoe, Successloop, Toquima, Winada, and Zeebar series.

Boneyard soils have more than 60 percent rock fragments in the particle-size control section. Chamberlain, Crandall, Forsey, Fourme, Jackflat, Packer, Successloop, and Zeebar soils are deeper than 100 cm. Itwo and Toquima soils are moderately deep to lithic contacts. Cowlow soils have Bk horizons with secondary carbonates. Scuffe soils have more than 15 percent cobbles in the particle-size control section. Stopatoe soils have less than 50 percent sand in the particle-size control section. Winada soils have 28 to 35 percent clay and less than 50 percent sand in the particle-size control section.

GEOGRAPHIC SETTING: Tagum soils are on mountains. They typically occur on shoulder and backslope positions. These soils formed in colluvium and residuum derived from granitic rock. Slopes are 15 to 50 percent. Elevations range from 2,380 to 2,870 meters. The climate is semiarid with cold, moist winters and cool, dry summers. The mean annual precipitation is 400 to 500 mm, mean annual temperature is 3 to 6 degrees C, and the frost-free period is 50 to 70 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bakscratch and Delhew soils and the competing Bullville soil. Bakscratch soils are loamy-skeletal, shallow to paralithic contacts, and have mollic epipedons and argillic horizons. Delhew soils are loamy-skeletal, very deep, and have argillic horizons and thick mollic epipedons.

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

USE AND VEGETATION: Tagum soils are used for rangeland and wildlife habitat. The present vegetation is mainly low sagebrush, pine needlegrass, and green ephedra.

DISTRIBUTION AND EXTENT: Western Nevada. These soils are not extensive. MLRA 26.

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

SERIES ESTABLISHED: Douglas County, Nevada, 2012.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 25 cm (A1, A2, and Bt1 horizons).
Argillic horizon - The zone from 13 to 76 cm (Bt1, Bt2, Bt3, and Bt4 horizons).
Paralithic contact - The boundary at 76 cm to underlying soft, weathered bedrock (Cr layer).
Particle-size control section - The zone from 13 to 63 cm (Bt1, Bt2, and Bt3 horizons and part of the Bt4 horizon).

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National Cooperative Soil Survey
U.S.A.