LOCATION AROSA NMEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, frigid Vertic Haplustolls
TYPICAL PEDON: Arosa silty clay loam, range. (Colors are for dry soil unless otherwise noted.)
A--0 to 10 inches; very dark gray (10YR 3/1) silty clay loam, black (10YR 2/1) moist; moderate medium platy in upper 2 inches, moderate very fine granular structure below 2 inches; slightly hard, friable, sticky, slightly plastic; many fine roots; many fine interstitial pores; neutral; clear smooth boundary. (6 to 18 inches thick)
Bw1--10 to 15 inches; very dark grayish brown (10YR 3/2) silty clay, very dark brown (10YR 2/2) moist; strong fine subangular blocky structure; very hard, firm, sticky, plastic; common fine and few coarse roots; common fine interstitial pores; neutral; clear smooth boundary. (4 to 8 inches thick)
Bw2--15 to 28 inches; very dark grayish brown (10YR 3/2) clay, very dark brown (10YR 2/2) moist; strong medium prismatic parting to moderate fine and medium angular and subangular blocky structure; very hard, firm, sticky, plastic; common fine and few coarse roots; common fine interstitial pores; neutral; clear smooth boundary. (8 to 20 inches thick)
Bw3--28 to 39 inches; very dark grayish brown (10YR 3/2) clay, very dark brown (10YR 2/2) moist; moderate medium and fine angular and subangular blocky structure; very hard, firm, very sticky, very plastic; few medium and coarse roots; few fine interstitial pores; neutral; clear smooth boundary. (10 to 15 inches thick)
Bw4--39 to 52 inches; brown (10YR 4/3) clay loam; dark brown (10YR 3/3) moist; moderate coarse subangular blocky structure; very hard, firm, sticky, plastic; few coarse roots; few fine interstitial pores; neutral; clear smooth boundary. (12 to 20 inches thick)
Bk--52 to 62 inches; brown (10YR 5/3) clay loam, dark brown (10YR 3/3) moist; weak coarse subangular blocky structure; hard, firm, sticky, plastic; few coarse roots; few fine interstitial pores; few fine masses of carbonates; slightly alkaline.
TYPE LOCATION: Otero County, New Mexico; about 1 mile southwest of Salt Well in a headcut; S1/4 corner of sec. 24, T.12S., R.16E.
RANGE IN CHARACTERISTICS:
Mean annual temperature ranges from about 43 degrees to 47 degrees F.
Soil Moisture - These soils are usually moist in the moisture control section with the driest period occurring during April, May, and June. Typic ustic moisture regime.
Reaction: slightly acid to mildly alkaline.
A horizon
Hue: 7.5YR or 10YR
Value: 3 or 4 dry and 2 or 3 moist
Chroma: 1 or 2 dry or moist
Organic matter: 2 to 10 percent
Bw1, Bw2, Bw3 horizons
Hue: 7.5YR or 10YR
Value: 3 or 4 dry and 2 or 3 moist
Chroma: 1 to 3 dry or moist
Texture: clay loam to clay
Clay content: 35 to 60 percent
Bw4 and Bk horizons
Hue: 5YR to 10YR
Value: 4 to 7 dry and 3 to 5 moist
Chroma: 2 to 4 dry or moist
Texture: clay loam or clay
Organic matter at depths of 50 inches exceeds 0.5 percent.
COMPETING SERIES: This is the Nusmag (NM) series. The Nusmag soils have a seasonal water table that is usually present during the months of March through June.
GEOGRAPHIC SETTING: The Arosa soils are on nearly level to moderately steep sloping alluvial fans and valley floors at elevations of 6,800 to 7,900 feet. The soils formed in alluvium mainly from mixed sedimentary and igneous rock. The mean annual precipitation is about 18 to 20 inches with a summer maximum. The average annual air temperature is about 41 degrees to 45 degrees F. The Thornthwaite P-E Index is about 30 to 45.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Brycan and Hesperus soils.
DRAINAGE AND PERMEABILITY: Well-drained; medium runoff; slow permeability.
USE AND VEGETATION: Major uses are native range, woodland, recreation, watershed and wildlife. Very limited use for cultivation. Principal native vegetation is sleepy grass, blue grama, sideoats grams, bluestem spp., and scattered ponderosa pine.
DISTRIBUTION AND EXTENT: These soils are of moderate extent in the central and southern mountains of New Mexico. MLRA 39.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Otero County (Mescalero-Apache Area), 1970.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from 0 to 10 inches (A horizon)
Vertic feature A linear extensibility of 6.0 cm or more in the zone between 10 and 40 inches (Bw1, Bw2, Bw3 horizons)
Classified according to Keys to Soil Taxonomy Ninth Edition, 2003.