LOCATION POOBAA                  NV

Established Series
Rev. GWM/PNL/TM/JBF
03/2012

POOBAA SERIES

The Poobaa series consists of moderately deep, well drained soils that formed in residuum and colluvium from andesite. The Poobaa soils are on hills. Slopes are 2 to 30 percent. The mean annual precipitation is about 230 mm and the mean annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Xeric Calciargids

TYPICAL PEDON: Poobaa loamy coarse sand--rangeland. (Colors are for dry soil unless otherwise noted.) The surface is covered with approximately 25 percent gravel.

A--0 to 13 cm; pale brown (10YR 6/3) loamy coarse sand, brown (10YR 4/3); weak thin platy structure parting to weak very fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; few fine roots; common fine vesicular and interstitial pores; 10 percent gravel; neutral (pH 7.2); clear smooth boundary. (8 to 18 cm thick)

Bt--13 to 41 cm; brown (10YR 5/3) sandy clay loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and medium, few coarse roots; common fine and medium interstitial and tubular pores; 10 percent gravel; common faint and distinct clay films lining pores; slightly alkaline (pH 7.6); clear smooth boundary. (15 to 30 cm thick)

Btk--41 to 64 cm; light brownish gray (10YR 6/2) gravelly coarse sandy loam; dark grayish brown (10YR 4/2) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; few fine and medium interstitial and tubular pores; 15 percent gravel; common faint and distinct clay films on ped faces; common spherical secondary calcium carbonate masses; common distinct secondary calcium carbonate masses around rock fragments; strongly effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary. (18 to 53 cm thick)

R--64 cm; hard, fractured, coarse-grained andesite with secondary calcium carbonate in fractures.

TYPE LOCATION: White Pine County, Nevada; approximately 4 miles south and 1.5 miles west of the intersection of Mike Springs road and Marble Wash road; about 2,620 feet south and 1110 feet east of the northwest corner of section 4, T. 19 N., R. 69 E.; latitude 39 degrees 32 minutes 28 seconds N and longitude 114 degrees 13 minutes 27 seconds W; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: Moist late fall through spring, usually dry July through October except for 10 to 20 days cumulative due to convection storms; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 8 to 11 degrees C.
Depth to lithic contact: 50 to 100 cm.

Particle-size control section - Percent clay: Averages 13 to 18 percent.
Rock fragments: 10 to 25 percent gravel, dominantly 2 to 5 mm in diameter.

A horizon
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 2 or 3.

Bt horizon
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 2 or 3 moist.
Clay content: 20 to 25 percent.
Calcium carbonate equivalent: 0 to 5 percent.
Rock fragments: 10 to 25 percent.

Btk horizon
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 2 or 3.
Texture: Gravelly coarse sandy loam, or sandy loam.
Clay content: 10 to 18 percent.
Rock fragments: 10 to 25 percent.
Calcium carbonate equivalent: 10 to 20 percent.

COMPETING SERIES: This is the Portmount series. Portmount soils are very deep.

GEOGRAPHIC SETTING: Poobaa soils are on concave hill side slopes. These soils formed in residuum and colluvium derived from coarse-grained andesite. Slope are 2 to 30 percent. Elevations are 2,075 to 2,230 meters. The climate is cool, semiarid with warm dry summers and cool moist winters. The mean annual precipitation is 200 to 250 mm, the mean annual temperature is 7 to 10 degrees C, and the frost-free season is 100 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Tarnach and Ultramont soils. Tarnach soils are shallow to a lithic contact. Ultramont soils are very deep.

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

USE AND VEGETATION: Range and wildlife habitat. The present vegetation is mainly Wyoming big sagebrush, Indian ricegrass, needleandthread and sand dropseed.

DISTRIBUTION AND EXTENT: East-central Nevada. These soils are not extensive. MLRA 28A.

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

SERIES ESTABLISHED: White Pine County, Nevada, East Part, 2004.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 13 cm (A horizon).
Argillic horizon - The zone from 13 to 64 cm (Bt and Btk horizons).
Calcic horizon - The zone from 41 to 64 cm (Btk horizon).
Lithic contact - The boundary at 64 cm (R layer).
Particle-size control section - The zone from 13 to 64 cm (Bt and Btk horizons).

---

National Cooperative Soil Survey
U.S.A.