LOCATION BLANCOT NMEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Ustic Haplargids
TYPICAL PEDON: Blancot loam--rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 2 inches; pale brown (10YR 6/3) loam, brown (10YR 5/3) moist; weak very fine granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine roots; few fine pores; moderately alkaline (pH 8.2); clear boundary. (2 to 4 inches thick)
AB--2 to 5 inches; pale brown (10YR 6/3) clay loam, brown (10YR 5/3) moist; weak medium platy and weak fine subangular blocky structure; soft, friable, sticky and plastic; few fine and hard medium roots; few fine pores; moderately alkaline (pH 8.2); clear smooth boundary. (2 to 4 inches thick)
Bt1--5 to 10 inches; brown (10YR 5/3) clay loam, brown (10YR 4/3) moist; weak medium and coarse subangular blocky structure; hard, friable, slightly sticky and plastic; few fine and medium roots; few fine and medium pores; thin patchy clay films lining pores and on faces of peds; moderately alkaline (pH 8.0); clear smooth boundary. (4 to 7 inches thick)
Bt2--10 to 15 inches; light brownish gray (2.5Y 6/2) clay loam, grayish brown (2.5Y 5/2) moist; weak coarse and medium subangular blocky structure; hard, firm, slightly sticky and plastic; few fine and medium roots; few fine and medium pores; few thin patchy clay films lining pores and on faces of peds; slightly effervescent with disseminated calcium carbonates; moderately alkaline (pH 8.0); clear smooth boundary. (3 to 7 inches thick)
C1--15 to 23 inches; light yellowish brown (2.5Y 6/4) sandy clay loam, light olive brown (2.5Y 5/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few fine and medium roots; few fine pores; slightly effervescent with disseminated calcium carbonate; moderately alkaline (pH 8.2); clear smooth boundary. (7 to 28 inches thick)
C2--23 to 60 inches; light brownish gray (2.5Y 6/2) clay loam, grayish brown (2.5Y 5/2) moist; massive; hard, friable, sticky and plastic; few fine and medium roots; few fine pores; strongly effervescent with disseminated calcium carbonates; strongly alkaline (pH 8.7).
TYPE LOCATION: San Juan County, New Mexico; 2,000 feet east, 2,200 feet north of the southeast corner sec. 2, T. 31 N., R. 11 W.
RANGE IN CHARACTERISTICS:
Soil moisture - Typically dry in all parts of the soil moisture control section from April 15 to July 1. The soil moisture control section is moist in some part periodically from July through October and moist intermittently from November to April 15. Ustic aridic moisture regime.
Soil temperature - 48 to 52 degrees F.
Particle-size control section: 18 to 35 percent clay
Reaction: neutral in the surface and slightly to moderately alkaline in the subsoil
A horizon -
Hue: 10YR or 2.5Y Value: 5 through 7 dry, 3 through 5 moist
Chroma: 2 through 4
Texture: fine sandy loam, loam, or silt loam
Bt horizon -
Hue: 10YR or 2.5Y
Value: 4 through 6 dry, 3 through 5 moist
Chroma: 2 to6 dry and moist
Texture: loam, sandy clay loam or clay loam
C horizon -
Hue: 10YR or 2.5Y
Value: 5 or 6 dry, 3 through 5 moist
Chroma: 2 to6 dry and moist
Texture: sandy loam, loam, sandy clay loam, clay loam, fine sandy loam, loamy sand, or silty clay loam
Some pedons have accumulations of secondary calcium carbonate.
COMPETING SERIES: Current competitors are the Balon (AZ), Bowbac (WY), Buckle (NM), Cambria (WY), Chilerojo (NM), Cushman (WY), Decolney (WY), Doakum (NM), Forkwood (WY), Fort (CO), Gaddes (AZ), Gapbutte (AZ), Gapmesa (AZ), Hagerman (NM), Hagerwest (NM), Hiland (WY), Mentmore (NM), Oelop (NM), Olney (CO), Palacid (NM), Penistaja (NM), Pokeman (WY), Potts (WY), Pugsley (WY), Quagwa (AZ), Redpen (NM), Spangler (WY), Sundance (CO), Tamarindo (NM), Teckla (WY) and Yenlo (CO) series. Balon and Decolney soils are noncalcareous throughout. Bowbac, Cushman, Gaddes, Gapbutte, Gapmesa, Hagerman, Hagerwest, Pokeman, Pugsley and Spangler soils have lithic or paralithic contacts at moderate depths. Buckle, Doakum, Oelop, Penistaja, and Quagwa soils have Bk horizons in the lower part of the profile. Mentmore soils have accumulations of calcium carbonate and gypsum. Oelop, Palacid, Penistaja and Redpen soils have hue redder than 10YR. Sundance soils have buried paleosol horizons. Teckla soils contain 35 to 70 percent porcelanite rock fragments below a 20 to 40 inch depth. Fort and Yenlo soils have Ck horizons in the lower part of the profile. In addition, the Bowbac, Cambria, Cushman, Decolney, Forkwood, Fort, Hagerman, Hiland, Olney, Pokeman, Potts, Pugsley, Spangler, Sundance, Tekla and Yenlo series are in LRR-G and are more moist in May and June.
GEOGRAPHIC SETTING: Blancot soils are on valley sides and ridges and have slopes of 0 to 8 percent. They formed in moderately fine-textured alluvium and fan alluvium from shale and sandstone. Elevations are 5,600 to 7,000 feet. The climate is semiarid. Mean annual precipitation is typically 10 to 13 inches, however a few areas are as low as 8 or 9 inches; mean annual temperature is 46 to 53 degrees F., and the frost-free period is about 100 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Avalon, Notal, and Turley soils lack argillic horizons.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow or moderate permeability.
USE AND VEGETATION: Used mainly for rangeland. Present native vegetation is galleta, big sagebrush, blue grama, Indian ricegrass, sand dropseed, alkali sacaton, western wheatgrass and scattered juniper and pinyon.
DISTRIBUTION AND EXTENT: Northwestern New Mexico. MLRA 35. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: San Juan County, New Mexico, Eastern Part, 1978.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: from 0 to 5 inches.
Argillic horizon: from 5 to 15 inches.
Classified according to Soil Taxonomy Second Edition, 1999.