LOCATION POLETA CA

Established Series
Rev. ET-MAV
06/2016

POLETA SERIES

The Poleta series consists of moderately deep, well drained soils that formed in mixed alluvium. Poleta soils are on stream terraces and have slopes of 0 to 2 percent. The mean annual precipitation is about 130 mm and the mean annual temperature is about 15 degrees C.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, thermic Cambidic Haplodurids

TYPICAL PEDON: Poleta loamy sand, on a slope of less than 1 percent at an elevation of 1,237 meters. (When described on September 30, 1987, the soil was dry throughout; colors are for dry soil unless otherwise stated).

A1--0 to 10 cm; light brownish gray (2.5Y 6/2) loamy sand, grayish brown (2.5Y 5/2) moist; weak medium platy parting to weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and few coarse roots; few fine vesicular pores; neutral (pH 7.0); gradual smooth boundary. (8 to 15 cm thick)

A2--10 to 41 cm; light yellowish brown (2.5Y 6/4) loamy sand, olive brown (2.5Y 4/4) moist, weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; few very fine and fine roots; few fine interstitial pores; neutral (pH 7.2); clear wavy boundary. (25 to 36 cm thick)

Bk--41 to 74 cm; light olive gray (5Y 6/2) sandy loam, olive (5Y 4/3) moist; moderate fine and medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; few fine tubular pores; strongly effervescent, carbonates segregated as common fine soft masses and concretions; slightly alkaline (pH 7.4); clear wavy boundary. (23 to 41 cm thick)

BC--74 to 97 cm; light olive gray (5Y 6/2) loamy sand; olive (5Y 5/3) moist; single grain; loose, loose, nonsticky and non- plastic; few very fine and fine roots; few fine interstitial pores; slightly alkaline (pH 7.4); abrupt smooth boundary. (0 to 30 cm thick)

2Bkqm--97 to 110 cm, white (5Y 8/1) strongly cemented duripan, light olive gray (5Y 6/2) moist; strong, medium and thick platy structure with thin (2mm) laminar cap; very hard, very firm and brittle; violently effervescent; strongly alkaline (pH 8.8); abrupt smooth boundary. (10 to 41 cm thick).

2B--110 to 152 cm; light gray (5Y 7/1) stratified gravelly coarse sand and sandy loam, olive gray (5Y 5/2) moist; massive with common thick platy pan fragments; soft, very friable, nonsticky and nonplastic; few fine interstitial pores; violently effervescent; strongly alkaline (pH 8.8).

TYPE LOCATION: Inyo County, California; about 3 miles southeast of Bishop; 200 feet north and 100 feet west of the SE corner of Sec. 16, T. 7 S., R. 33 E., USGS Poleta Canyon 7.5 minute topographic quadrangle; latitude 37 degrees 19 minutes 58 seconds N and longitude 118 degrees 21 minutes 01 seconds W; WGS84 Decimal Degrees 37.3327778 latitude, -118.3502778 longitude.

RANGE IN CHARACTERISTICS: The mean annual soil temperature is 15 to 17.8 degrees C. The soil temperature is below 8.3 degrees C from about December 1 to March 1, and is below 5 degrees C from about January 1 to February 1. The soil between the depths of 36 and 107 cm is dry throughout for 200 to 225 days from about May 15 to December 15. It is moist throughout for 65 to 80 days from about January 15 to April 1 and is moist in some or all parts for 70 to 85 consecutive days from about March 1 to May 15 when the soil is above 8.3 degrees C.; aridic moisture regime bordering on xeric. Duripan is at a depth of 51 to 102 cm. Electrical conductivity is 0 to 2 dS/m.

The A horizon color is 2.5Y 6/2, 6/4, 7/2; 10YR 6/2, 6/3 or 7/2. Moist color is 2.5Y 4/2, 4/4, 5/2; 10YR 4/3, or 5/2. Textures are sand, loamy sand or sandy loam with 2 to 8 percent clay. Reaction is neutral through moderately alkaline.

The Bk horizon color is 5Y 5/1, 6/2, 7/2; 2.5Y 6/2 or 7/2. Moist color is 5Y 4/3, 5/2, 5/3; or 2.5Y 5/2. Texture is loamy sand or sandy loam with 5 to 15 percent clay. Most pedons have a BC horizon with similar colors. Textures are sandy loam or loamy sand. Reaction is slightly or moderately alkaline.

The 2Bkqm horizon is a strongly cemented duripan with colors of 5Y 7/1, 7/2, 8/1 or 8/2. Moist color is 5Y 5/2, or 6/2.

The 2B horizon color is 2.5Y 6/2, 7/2; 5Y 6/1 or 7/1. Moist color is 2.5Y 5/2, 5/3; 5Y 4/2 or 5/2. Textures are stratified sand, loamy sand, sandy loam or gravelly coarse sand averaging 4 to 10 percent clay. Reaction is moderately or strongly alkaline.

COMPETING SERIES: There are no other series in this family. Similar soils in another family are the Montezuma (T) soils. The Montezuma (T) soils do not have an indurated duripan. They also have a mesic temperature regime and an ashy mineralogy.

GEOGRAPHIC SETTING: Poleta soils are on stream terraces. Slopes are 0 to 2 percent. The soils formed in alluvium from mixed sources. Elevations are 1,122 to 1,280 meters. The climate is arid with hot dry summers and cool moist winters; aridic moisture regime bordering on xeric. The mean annual precipitation is 100 to 150 mm. The mean annual temperature is 13.9 to 16.1 degrees C. Mean July temperature is about 26.7 degrees C, and mean January temperature is about 4.4 degrees C. The frost-free season is 140 to 225 days.

GEOGRAPHICALLY ASSOCIATED SOILS ARE: These are the Inyo (T), and Westguard (T) soils. Inyo soils do not have a duripan and are excessively drained; Westguard (T) soils have an argillic horizon. All of these soils are on stream terraces.

DRAINAGE AND PERMEABILITY: Well drained; very slow runoff; moderately rapid permeability above the pan.

USE AND VEGETATION: Poleta soils are used for rangeland and wildlife habitat. Vegetation is shadscale, bud sagebrush, spiny hopsage and Indian ricegrass.

DISTRIBUTION AND EXTENT: Owens Valley of eastern California. The series is not extensive in MLRA 29.

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

SERIES PROPOSED: Benton-Owens Valley Area, Inyo County, California, 1989. The name is from a nearby abandoned train station.

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

1. Ochric epipedon -- 0 to 18 cm (A1, and part of the A2).

2. Duripan 97 to 110 cm (Bkqm). Continuous silica laminar cap, does not slake in HCl.

2.1 Hard, firm consistency - does not slake in HCl.

3. Thermic temperature regime -- mean annual soil temperature 15 to 17.8 degrees C.

4. Mineralogy -- assumed mixed.

5. Particle size class -- coarse-loamy based on hydrometer and field estimates of the 25 to 97 cm control section.

6. Moisture regime -- Aridic bordering on Xeric. Xerollic subgroup -- Dry throughout more than 1/2 of the time but less than 3/4 when the soil temperature is above 41 degrees. Also moist in some or all part more than 90 days.

6.1 The moisture control section is dry throughout from May 15 to December 15. It is moist throughout from January 15 to April 1.

6.2 The soil temperature exceeds 5 degrees C.
From February 1 to January 1 (335 days). Within this time period, the moisture control section is dry from May 15 to December 15 (210 days).

6.3 The soil temperature exceeds 8.3 degrees C from March 1 to December 1 (270 days). Within this time period, the moisture control section is dry from May 15 to December 1 (195 days).

National Cooperative Soil Survey
U.S.A.