LOCATION HESHOTAUTHLA NMEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, mesic Aridic Natrustolls
TYPICAL PEDON: Heshotauthla clay--in rangeland on a linear surface of 1 percent slope at an elevation of 6680 feet. (Colors are for dry soils unless otherwise noted.)
ABn--0 to 3 inches; brown (10YR 5/3) clay, dark brown (10YR 3/3) moist; moderate medium prismatic structure; very hard, very firm, very sticky and very plastic; few very fine roots; many fine and medium vesicular pores; strongly effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (0 to 3 inches thick)
Btn1--3 to 9 inches; brown (10YR 5/3) clay, dark brown (10YR 3/3) moist; weak coarse prismatic structure parting to moderate coarse subangular blocky; extremely hard, very firm, very sticky and very plastic; common very fine and fine roots; few very fine irregular pores; many prominent clay films on faces of peds; common slickensides up to 2 inch diameter; strongly effervescent; strongly alkaline (pH 8.6); clear wavy boundary. (The combined thickness of the Bt horizons is 16 to 45 inches.)
Btn2--9 to 18 inches; brown (10YR 5/3) clay dark brown (10YR 3/3) moist; moderate medium and coarse subangular blocky structure; extremely hard, very firm, very sticky and very plastic; few very fine roots; few very fine irregular pores; many prominent clay films on faces of peds; strongly effervescent; strongly alkaline (pH 9.0); gradual wavy boundary. (The combined thickness of the Bt horizons is 16 to 45 inches.)
Btkz--18 to 32 inches; brown (10YR 5/3) clay, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; extremely hard, very firm, very sticky and very plastic; few very fine roots; few very fine irregular pores; common distinct clay films on faces of peds; strongly effervescent, few fine soft masses of calcium carbonate; few fine salt crystals; moderately alkaline (pH 8.2); gradual irregular boundary. (The combined thickness of the Bt horizons is 16 to 45 inches.)
Bkz--32 to 65 inches; brown (10YR 5/3) clay, dark brown (10YR 3/3) moist; massive; extremely hard, very firm, very sticky and very plastic; few very fine roots; few very fine irregular pores; strongly effervescent, few fine soft masses of calcium carbonate; common fine and medium salt crystals; moderately alkaline (pH 8.2). (20 to 46 inches thick)
TYPE LOCATION: McKinley County, New Mexico; Horsehead Canyon NW Quadrangle; about .7 miles south of Nutria Reservoir No. 4 on the Zuni Indian Reservation; 2000 feet north and 200 feet west of the southeast corner of Sec. 5, T11N, R17W; 108 degrees 38 minutes 43 seconds west longitude, 35 degrees 12 minutes 43 seconds north latitude.
RANGE IN CHARACTERISTICS:
Soil Moisture: The SMCS is usually moist, in all parts, for less than 90 cumulative days from April through October. It is usually dry, in some part, for more than 120 days cumulative days during the same period. It is continuously moist in some part November through April, but not moist all parts for 45 consecutive days from January through April. The period of maximum precipitation is July through October. The soil is driest during May and June. Aridic ustic moisture regime.
Soil Temperature: 48 to 51 degrees F
Particle-size control section: 48 to 60 percent clay
Reaction: moderately to very strongly alkaline
Depth to salt (mostly sodium sulfate) crystals: 18 to 35 inches
E horizon (may be absent):
Value: 4 or 5 dry
Chroma: 2 or 3
Percent calcium carbonate equivalent: less than 5
Sodicity: SAR of 10 to 20
Salinity: EC of 1 to 2 mmhos/cm
Btn horizons:
Hue: 7.5YR or 10YR
Value: 4 or 5 dry
Chroma: 2 or 4
Percent calcium carbonate equivalent: less than 5
Salinity: EC of 2 to 4 mmhos/cm
Sodicity: SAR of 20 to 40
Bkz horizon:
Hue: 7.5YR or 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 3 or 4
Percent calcium carbonate equivalent: less than 5
Sodicity: SAR of 15 to 35 Salinity: EC of 5 to 10 mmhos/cm
COMPETING SERIES: There are no competitors.
GEOGRAPHIC SETTING: The Heshotauthla soils formed in alluvium and stream alluvium derived from sandstone and shale on stream terraces of valley floors. This soil is subject to occasional very brief flooding from April to October. Slopes are 0 to 1 percent. Elevations range from 6,300 to 7,000 feet. The mean annual temperature is 46 to 49 degrees F., and the mean annual precipitation is 13 to 16 inches. The frost free period is 100 to 135 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the proposed Knifehill, Concho and Hosta soils on valley floors. All these soils lack a natric horizon.
DRAINAGE AND PERMEABILITY: Well drained; very slow to high runoff; very slow permeability.
USE AND VEGETATION: These soils are used for livestock grazing. Present vegetation is western wheatgrass, alkali sacaton, galleta, mat muhly, black greasewood, and fourwing saltbush.
DISTRIBUTION AND EXTENT: West central New Mexico. MLRA 35, LRR-D. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: McKinley County Area, New Mexico; McKinley County and Parts of Cibola and San Juan Counties, 2001.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the surface to a depth of 32 inches.
Natric horizon - The zone from 3 to 18 inches. (Btn horizons)
Cation exchange activity class was changed from superactive to active in December 2000.
Classified according to Soil Taxonomy Second Edition, 1999.
ADDITIONAL DATA:
NSSL S88NM-031-012