LOCATION POBLANO NMEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, mixed, superactive, mesic Pachic Argiustolls
TYPICAL PEDON: Poblano very cobbly clay loam--rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 2 inches; brown (7.5YR 4/2) crushed, very cobbly clay loam, very dark brown (7.5YR 2.5/2) crushed, moist; weak fine granular structure; slightly hard, friable; slightly sticky and slightly plastic; common fine roots throughout; 34 percent clay; 20 percent nonflat subrounded 0.1- to 3-inch monzonite gravel, 15 percent nonflat subrounded 3- to 10-inch monzonite cobbles, 10 percent nonflat subrounded 10- to 24-inch monzonite stones and 10 percent nonflat subrounded greater than 24-inch monzonite boulders; noneffervescent by HCL, 1 normal; neutral; clear smooth boundary. (0 to 4 inches thick)
Bt1--2 to 6 inches; brown (7.5YR 4/2) crushed, very cobbly clay, very dark brown (7.5YR 2.5/3) crushed, moist; moderate medium subangular blocky structure; hard, extremely firm; moderately sticky and moderately plastic; few fine and medium roots throughout; few fine dendritic tubular pores; 42 percent clay; 20 percent patchy distinct clay films on faces of peds; 20 percent nonflat subrounded 0.1- to 3-inch monzonite gravel, 15 percent nonflat subrounded 3- to 10-inch monzonite cobbles and 5 percent nonflat subrounded 10- to 24-inch monzonite stones; noneffervescent by HCL, 1 normal; neutral; gradual wavy boundary. (2 to 8 inches thick)
Bt2--6 to 11 inches; brown (7.5YR 4/3) crushed, very stony clay, dark brown (7.5YR 3/2) crushed, moist; moderate coarse subangular blocky structure; very hard, extremely firm; very sticky and very plastic; few fine roots throughout; few fine dendritic tubular pores; 48 percent clay; 40 percent continuous prominent clay films on faces of peds; 10 percent nonflat subrounded 0.1- to 3-inch monzonite gravel, 15 percent nonflat subrounded 3- to 10-inch monzonite cobbles and 15 percent nonflat subrounded 10- to 24-inch monzonite stones; noneffervescent by HCL, 1 normal; neutral; gradual wavy boundary. (3 to 8 inches thick)
Bt3--11 to 27 inches; brown (7.5YR 5/2) crushed, very cobbly clay, dark brown (7.5YR 3/3) crushed, moist; moderate coarse subangular blocky structure; very hard extremely, firm; very sticky and very plastic; few fine roots throughout; few fine dendritic tubular pores; 50 percent clay; 50 percent continuous prominent clay films on faces of peds; 20 percent nonflat subrounded 0.1- to 3-inch monzonite gravel and 15 percent nonflat subrounded 3- to 10-inch monzonite cobbles; noneffervescent by HCL, 1 normal; neutral; abrupt smooth boundary. (10 to 20 inches thick)
Btk--27 to 34 inches; brown (7.5YR 5/4) crushed, gravelly clay, brown (7.5YR 4/4) crushed, moist; weak coarse subangular blocky structure; very hard, extremely firm; very sticky and very plastic; few fine roots throughout; few fine dendritic tubular pores; 45 percent clay; 5 percent medium, irregular calcium carbonate masses on faces of peds; 20 percent patchy prominent clay films on faces of peds; 15 percent nonflat subrounded 0.1- to 3-inch monzonite gravel; slight effervescence with violent effervescence in patches by HCL, 1 normal; moderately alkaline; gradual wavy boundary. (4 to 13 inches thick)
Crk--34 to 42 inches; reddish yellow; coarsely fractured weathered monzonite bedrock; 5 percent medium, irregular calcium carbonate masses in matrix; abrupt smooth boundary. (8 to 12 inches thick)
R--42 inches; thickly bedded massive monzonite.
TYPE LOCATION: Dona Ana County, New Mexico; approximately 3.7 miles west and 5.7 miles south of White Sands; 4,600 feet east and 500 feet north of the southwest corner of sec. 21, T. 23 S., R. 4 E. USGS Organ Peak topographic quadrangle; latitude 32 degrees, 17 minutes, 22 seconds north and longitude 106 degrees 32 minutes 34 seconds west. UTM zone 13S 354712E, 3573485N; NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture: The moisture control section is usually dry in some or in all parts for six-tenths or more of the time that the soil temperature exceeds 41 degrees F. Some part of the epipedon is moist for more than 90 cumulative days in most years when the soil temperature exceeds 41 degrees F. Aridic ustic moisture regime.
Mean annual soil temperature: 55 to 59 degrees F.
Depth to lithic contact: 40 to 60 inches
Depth to paralithic contact: 30 to 40 inches
Depth to argillic horizon: 0 to 4 inches
Thickness of mollic epipedon: 20 to 30 inches
Particle-size control section (weighted average):
Clay content: 40 to 60 percent
Coarse fragment content: 35 to 55 percent
A horizon:
Hue: 5YR or 7.5YR
Value: 3 or 4 dry, 2.5 or 3 moist
Chroma: 1 to 3, dry or moist
Coarse fragments: monzonite fragments; 35 to 55 percent total coarse fragments; 10 to 30 percent gravel; 10 to 20 percent cobbles, 10 to 15 percent stones and 5 to 15 percent boulders.
Bt horizons:
Hue: 5YR or 7.5YR
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 1 to 3, dry or moist
Texture modifier: gravelly, very gravelly, very cobbly, or very stony
Coarse fragments: monzonite fragments; 25 to 55 percent total coarse fragments; 15 to 35 percent gravel; 5 to 25 percent cobbles and 0 to 15 percent stones.
Btk horizon:
Hue: 5YR or 7.5YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 4 or 6, dry or moist
Texture modifier: gravelly or very gravelly
Coarse fragments: monzonite fragments; 15 to 25 percent total coarse fragments; 10 to 25 percent gravel; 0 to 5 percent cobbles.
Texture: clay loam and clay
COMPETING SERIES: This is the
Sanloren (NM) series.
Sanloren soils are very deep.
GEOGRAPHIC SETTING:
Parent material: colluvium and alluvium from monzonite
Landform: mountain flanks and bases
Slope: 5 to 35 percent
Mean annual temperature: 54 to 57 degrees
Mean annual precipitation: 14 to 16 inches
Precipitation pattern: precipitation falls mostly during the months of July through September. The driest months are March and April. Precipitation during the months of January, February, and March is less than 13 percent of the total.
Frost-free period: 130 to 170 days
Elevation: 5,800 to 6,800 feet
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Brewster,
Rotagilla, and
Sotol soils.
Brewster and Rotagilla soils are shallow and very shallow to bedrock and are on mountain tops and flanks.
Sotol soils have mollic epipedons less than 20 inches thick and are on mountain flanks and bases.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is slow. Runoff is very high on slopes of 5 to 35 percent.
USE AND VEGETATION: Used for livestock grazing. Vegetation is of the Pinyon-Juniper-Oak savannah type consisting of sideoats grama, blue grama, metcalf muhly, bull muhly, wolftail, alligator juniper, pinyon pine, oak spp., and mesquite.
DISTRIBUTION AND EXTENT: Southern New Mexico; LRR D, MLRA 42. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona.
SERIES ESTABLISHED: Dona Ana County, New Mexico; 2001.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 2 to 22 inches. (Bt1, Bt2, and Bt3 horizons)
Mollic epipedon: The zone from 0 to 27 inches. (A, Bt1, Bt2, and Bt3 horizons).
Argillic horizon: The zone from 2 to 34 inches. (Bt1, Bt2, and Bt3 horizons).
The assignment of the cation exchange capacity is inferred from lab data from similar soils in the surrounding area.