LOCATION COCHITI NMEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, mixed, superactive, mesic Aridic Haplustalfs
TYPICAL PEDON: Cochiti gravelly loam--woodland. (Colors are for dry soil unless otherwise stated.)
A--0 to 7 inches; dark yellowish brown (10YR 4/4) gravelly loam, dark brown (10YR 3/3) moist; weak fine granular structure; slightly hard, firm, moderately sticky and moderately plastic; many fine and medium roots; 5 percent cobbles, 15 percent gravel; neutral; clear smooth boundary. (3 to 8 inches thick)
Bt1--7 to 12 inches; reddish brown (5YR 4/3) very gravelly clay loam, reddish brown (5YR 4/3) moist; strong medium subangular blocky structure; very hard, firm, very sticky and very plastic; common fine and coarse roots; thick continuous clay films on faces of peds; 30 percent gravel, 5 percent cobbles; slightly acid; clear smooth boundary. (4 to 10 inches thick)
Bt2--12 to 20 inches; reddish brown (5YR 4/4) very gravelly clay, reddish brown (5YR 4/4) moist; strong medium and coarse subangular blocky structure; very hard, firm, very sticky and very plastic; few fine and coarse roots; thick continuous clay films on faces of peds; 40 percent gravel, 5 percent cobbles; neutral; clear smooth boundary. (4 to 12 inches thick)
Bt3--20 to 29 inches; light reddish brown (5YR 6/4) very gravelly clay loam, reddish brown (5YR 5/4) moist; weak medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few fine and coarse roots; thin and continuous clay films on faces of peds; 40 percent gravel, 5 percent cobbles; neutral; clear smooth boundary. (5 to 15 inches thick)
2C--29 to 60 inches; light reddish brown (5YR 6/4) very gravelly sandy loam; reddish brown (5YR 5/4) moist; massive; loose, nonsticky and nonplastic; few fine and coarse roots; 50 percent gravel, 5 percent cobbles; neutral.
TYPE LOCATION: Sandoval County, New Mexico; 10 miles west of Cochiti Pueblo; 1,500 feet east of 300 feet north of the center sec. 11, T. 16 N., R. 4 E.; Canada USGS quad; approximate lat. 35 degrees 37 minutes 58 seconds N. and long. 106 degrees 28 minutes 55 seconds W., NAD 27.
RANGE IN CHARACTERISTICS: Soil moisture: The soil moisture control section is moist in some part during the 120 days following the winter solstice and is moist in all parts less than 25 percent of the time that the soil temperature at 20 inch depths is above 40 degrees F.
Mean annual soil temperature: 52 to 54 degrees F.
Depth to the base of the Bt: 16 to 45 inches.
Particle-size control section
Clay content: 35 to 45 percent.
Rock fragments: 35 to 50 percent by volume with 5 to 10 percent cobbles and 30 to 40 percent gravel.
A horizon
Hue: 7.5YR or 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 3 or 4
When colors meet the requirements for a mollic epipedon, the horizon is less than 7 inches thick.
Texture: Gravelly loam or extremely gravelly loam
Bt horizons
Hue: 7.5YR or 5YR
Value: 4 through 6 dry, 4 or 5 moist
Chroma: 3 or 4
Texture: Very gravelly clay or very gravelly clay loam.
2C horizon
Hue: 7.5YR or 5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 through 6
Texture: Very gravelly loamy sand or very gravelly sandy loam
Rock fragment content: 40 to 60 percent; 5 to 10 percent cobbles and 35 to 50 percent gravel.
COMPETING SERIES: These are Devisadero and Patos soils. Devisadero soils have bedrock within 40 inches. Patos soils have a calcic horizon.
GEOGRAPHIC SETTING: Cochiti soils are on gravelly fan terraces. Slopes are 1 to 40 percent. Average annual precipitation ranges from 12 to 14 inches, average annual temperature ranges from 50 to 52 degrees F., and the average frost-free period ranges from 110 to 130 days. Elevation ranges from 5,300 to 7,500 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Montecito and Frijoles soils. Montecito soils are fine-textured, and Frijoles soils are developed from pumice and have less than 35 percent clay.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; slow permeability.
USE AND VEGETATION: These soils are used for grazing. Native vegetation is pinyon, oneseed juniper, western wheatgrass, blue grama, and galleta.
DISTRIBUTION AND EXTENT: This soil occurs in northcentral New Mexico and is of small extent. MLRA 36.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Sandoval County, New Mexico; 1980.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon: The zone from the surface to a depth of 7 inches. (A horizon)
Argillic horizon: The zone from 7 to 29 inches. (Bt1, Bt2, Bt3 horizons)
Taxonomic version: Classified according to Keys to Soil Taxonomy, Tenth Edition, 2006.