LOCATION SUPOSO NM+CO
Established Series
Rev. LWH-TWH-KLS
01/2023
SUPOSO SERIES
The Suposo series consists of very deep, well drained, slowly permeable soils that formed in alluvium derived from sandstone and shale. These soils are on stream terraces, valley sides and valley floors and have slopes of 1 to 6 percent. Mean annual precipitation is about 432 mm and mean annual air temperature is about 6.1 degrees C.
TAXONOMIC CLASS: Fine, smectitic, frigid Vertic Argiustolls
TYPICAL PEDON: Suposo clay loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 10 cm; dark grayish brown (10YR 4/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; soft, very friable, moderately sticky and moderately plastic; common very fine, fine and few medium roots; neutral; clear smooth boundary. (10 to 15 cm thick)
Bt--10 to 41 cm; grayish brown (10YR 5/2) clay, very dark grayish brown (10YR 3/2) moist; moderate fine angular blocky structure; hard, firm, moderately sticky and moderately plastic; many very fine, fine and common medium roots; few thin clay films on faces of peds; neutral; clear smooth boundary. (18 to 30 cm thick)
Btk--41 to 79 cm; dark grayish brown (10YR 4/2) clay, very dark grayish brown (10YR 3/2) moist; moderate medium prismatic structure; very hard, very firm, very sticky and very plastic; common very fine, few fine and medium roots; few thin clay films on faces of peds; calcium carbonate segregated as thin filaments and threads; strongly effervescent; slightly alkaline; clear smooth boundary. (23 to 43 cm thick)
BCk--79 to 152 cm; brown (10YR 5/3) clay, very dark grayish brown (10YR 3/2) moist; weak medium prismatic structure; very hard, very firm, very sticky and very plastic; few very fine, fine and medium roots; calcium carbonate segregated as thin filaments and threads; strongly effervescent; slightly alkaline.
TYPE LOCATION: Rio Arriba County, New Mexico; about two miles north of Lumberton, New Mexico state plane coordinates 661,089 meters north and 91,501 meters east; Lat. 36 degrees, 57 minutes, 30 seconds N. and Long.
106 degrees, 55 minutes, 58 seconds, W.
RANGE IN CHARACTERISTICS:
Soil Moisture: Intermittently moist in the SMCS November through March and July through September. The soil is driest during May and June.
Mean annual soil temperature: 5.6 to 8.3 degrees C.
Mollic epipedon thickness: 46 to 79 cm
Depth to the base of the Bt horizon: 51 to 89 cm
Particle-size control section:
Weighted average percent clay: 40 to 55 percent
A horizon
Hue: l0YR or 2.5Y
Value: 4 or 5 dry, 1 to 3 moist
Chroma: 2 or 3, dry or moist
Reaction (pH): 6.6 to 7.3
Bt horizon(s)
Hue: l0YR or 2.5Y
Value: 3 to 5 dry, 1 to 3 moist
Chroma: 2 or 3, dry or moist
Texture: clay loam, clay
Reaction (pH): 6.6 to 7.8
Btk, BCk horizon (includes a Bk in some pedons)
Hue: l0YR or 2.5Y
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 2 or 3, dry or moist
Texture: clay, clay loam
Calcium carbonate equivalent: 5 to 10 percent
Reaction (pH): 6.6 to 7.8
COMPETING SERIES:
Bearpaw (MT) - have a mollic epipedon less than 45 cm thick
Burnel (MT) - are not driest in the moisture control section in May
Cedarsprings (NM) - do not have horizons of secondary carbonates
Cerro (CO) - have rock fragments
Coben (MT) - have a mollic epipedon less than 45 cm thick
Danvers (MT) - have a mollic epipedon less than 45 cm thick
Fergus (MT) - have a mollic epipedon less than 45 cm thick
Friana (AZ) - have rock fragments
Gerbana (MT) - are moderately deep to paralithic bedrock
Gerber (MT) - have a mollic epipedon less than 45 cm thick
Mondamin (SD) - have a mollic epipedon less than 45 cm thick
Nunnston (WY) - have a mollic epipedon less than 45 cm thick
Pagoda (CO) - are moist in the moisture control section for longer periods
Regent (ND) - are moderately deep to paralithic contact
Reget (WY) - are moderately deep to paralithic contact
Ridgeview (SD) - have a mollic epipedon less than 45 cm thick
Wyola (MT) - have a mollic epipedon less than 45 cm thick
Tomasaki (UT) - have a mollic epipedon less than 45 cm thick
Tsoodzil (NM) - do not have horizons of secondary carbonates
Yankee (NM) - formed in material weathered from basalt and have basalt rock fragments
GEOGRAPHIC SETTING:
Landform - stream terraces, valley sides, and valley floors
Elevation - 2,070 to 2,590 meters
Slopes - 1 to 6 percent
Parent material - alluvium derived from sandstone and shale
Mean annual precipitation - 400 to 460 mm
Mean annual air temperature - 4.4 to 7.2 degrees C.
Frost-free period - 80 to l00 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; and slow permeability.
USE AND VEGETATION: Suposo soils are used for livestock grazing and wildlife habitat. The present vegetation is sagebrush, rabbitbrush, snakeweed, western wheatgrass, and bluegrass.
DISTRIBUTION AND EXTENT: Northern New Mexico and southern Colorado; LRR D, E; MLRA 36, 48A; moderate extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Rio Arriba County, New Mexico, l989.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 79 cm (A, Bt horizons)
Argillic horizon - 10 to 79 cm (Bt horizons)
Note: the dark colors below the mollic epipedon are lithochromic
Suposo soils have a frigid temperature regime and are in an ustic soil moisture regime with a typic subclass.
National Cooperative Soil Survey
U.S.A.