LOCATION ALTEGA NMTentative Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Aridic Haplustalfs
TYPICAL PEDON: Altega loam--on a summit of an undulating plateau sloping 3 percent to the east southeast at 7,490 feet elevation--rangeland. (Colors are for dry soil unless otherwise noted. When described, the profile was dry throughout.)
A--0 to 2 inches; brown (10YR 4/3) loam, dark brown (10YR 3/3) moist; weak fine granular structure; soft, very friable, slightly sticky and nonplastic; common fine and few very fine roots; few very fine irregularly shaped pores; slightly alkaline (pH 7.6); abrupt smooth boundary. (1 to 3 inches thick)
Bt1--2 to 9 inches; yellowish brown (10YR 5/4) loam, dark yellowish brown (10YR 3/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few medium, common fine, and few very fine roots; few fine tubular pores; few faint clay films on faces of peds; slightly alkaline (pH 7.6); abrupt smooth boundary.
Bt2--9 to 19 inches; brown (7.5YR 5/4) loam, dark brown (7.5YR 3/4) moist; moderate medium subangular blocky structure; hard, friable, moderately sticky and slightly plastic; few coarse, few medium, few fine, and few very fine roots; common fine tubular pores; few faint clay films on faces of peds; neutral (pH 7.2); abrupt smooth boundary. (combined thickness of the Bt horizons is 12 to 30 inches)
Btk--19 to 24 inches; brown (7.5YR 5/3) loam, brown (7.5YR 4/3) moist; moderate medium angular blocky structure; hard, firm, moderately sticky and slightly plastic; few fine and few very fine roots; common fine tubular pores; few faint clay films on faces of peds; strongly effervescent, secondary calcium carbonate segregated as few medium irregularly shaped coats on faces of peds; slightly alkaline (pH 7.4); clear smooth boundary. (5 to 16 inches thick)
BAtkb--24 to 29 inches; brown (7.5YR 4/3) loam, dark brown (7.5YR 3/2) moist; moderate fine angular blocky structure; hard, friable, moderately sticky and slightly plastic; few fine and few very fine roots; common fine tubular pores; few distinct and few faint clay films on faces of peds; violently effervescent, secondary calcium carbonate segregated as many coarse irregularly shaped coats on faces of peds; moderately alkaline (pH 8.4); clear smooth boundary. (0 to 10 inches thick)
Btkb1--29 to 43 inches; light brown (7.5YR 6/4) clay loam, brown (7.5YR 4/4) moist; moderate fine angular blocky structure; hard, friable, moderately sticky and moderately plastic; few fine and few very fine roots; few fine and few very fine tubular pores; few faint clay films on faces of peds; violently effervescent, secondary calcium carbonate segregated as many coarse irregularly shaped coats on faces of peds; strongly alkaline (pH 8.6); clear wavy boundary.
Btkb2--43 to 58 inches; light brown (7.5YR 6/3) loam, brown (7.5YR 4/3) moist; moderate fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few common, few fine and few very fine roots; few very fine tubular pores; few faint clay films on faces of peds; strongly effervescent, secondary calcium carbonate segregated as few fine irregularly shaped coats on faces of peds; moderately alkaline (pH 8.4); clear wavy boundary. (combined thickness of the Btkb horizon is 6 to 30 inches.)
Bkb1--58 to 81 inches; reddish yellow (7.5YR 6/6) loam, strong brown (7.5YR 4/6) moist; moderate medium angular blocky structure; hard, firm, slightly sticky and nonplastic; few fine roots; few very fine tubular pores; 5 percent gravel; violently effervescent, secondary calcium carbonate segregated as few coarse and common medium irregularly shaped coats on faces of peds; moderately alkaline (pH 8.4); clear wavy boundary. (10 to 23 inches thick).
Bkb2--81 to 101 inches; reddish yellow (7.5YR 7/6) loam, strong brown (7.5YR 4/6) moist; weak medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common fine and many very fine tubular pores; 5 percent gravel; slightly effervescent, secondary calcium carbonate segregated as few medium irregularly shaped coats on faces of peds; strongly alkaline (pH 8.8); abrupt wavy boundary. (0 to 20 inches thick).
2R--101 to 111 inches; very strongly cemented sandstone bedrock.
TYPE LOCATION: Santa Fe County, New Mexico; 2,225 feet east and 650 feet north of the southwest corner of section 9, T.15N., R.11E.; USGS Glorieta 7.5 minute topographic quadrangle; Latitude 35 degrees 32 minutes 16 seconds North and Longitude 105 degrees 46 minutes 49 seconds West, NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture The soil moisture control section is moist in all parts during the 60 days following the winter solstice. It is moist in some part less than 40 percent and moist in all parts less than 25 percent of the time when the soil temperature at 20 inches is above 41 degrees F. The soils are driest in May and June. The soil moisture regime is aridic ustic.
Soil temperature - 49 to 51 degrees F.
Depth to base of argillic horizon - 40 to 66 inches
Depth to calcareous material (as visible secondary calcium carbonate) - 15 to 30 inches
Reaction - slightly alkaline in the surface; neutral to moderately alkaline and upper part of the subsoil; moderately alkaline to strongly alkaline in the lower part of the subsoil and in the substratum
Salinity: 0 to 1
Sodicity, SAR: 0 to 2
Buried horizons do not occur in all pedons.
Particle size control section weighted averages: -
Silicate clay content: 25 to 35 percent
Sand content: 25 to 40 percent
Fine sand or coarser content: 8 to 15 percent
Rock fragment content: 2 to 5 percent gravel, lithology of fragments is sandstone
A horizon
Hue: 7.5YR or 10YR
Value: 3 to dry, 3 or 4 moist
Chroma: 2 to 4 dry, 1 to 4 moist
Rock fragments: 2 to 5 percent, mostly gravel
Bt horizons
Hue: 7.5YR or 10YR
Value: 3 through 5 dry, 2 to 4 moist
Chroma: 2 to 5 dry, 2 to 4 moist
Texture: loam or clay loam
Rock fragments: 2 to 12 percent, mostly gravel
Other features: when color value moist is 3 or less, color chroma moist is 4 (non-mollic)
Btk horizon
Hue: 7.5YR or 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 to 4, 2 to 4 moist
Texture: loam or clay loam
Rock fragments: 2 to 5 percent, mostly gravel
Calcium carbonate equivalent: 1 to 3 percent
BAtkb horizon (where present)
Hue: 7.5YR or 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 to 4, 2 to 4 moist
Texture: loam or clay loam
Rock fragments: 2 to 5 percent, mostly gravel
Calcium carbonate equivalent: 1 to 3 percent
Btkb horizons
Value: 6 dry, 4 moist
Chroma: 3 or 4, dry or moist
Texture: loam or clay loam
Rock fragments: 0 to 5 percent, mostly gravel
Calcium carbonate equivalent: 1 to 3 percent
Bkb horizons
Hue: 7.5YR or 10YR
Value: 4 to 7 dry, 3 or 4 moist
Chroma: 2 to 8 dry, 2 to 6 moist
Texture: gravelly loam or loam
Rock fragments: 3 to 20 percent, mostly gravel
Calcium carbonate equivalent: 1 to 3 percent
COMPETING SERIES: These are the Amal(NM), Buick(CO), Chevelon(AZ), Chita(NM), Elpedro(NM), Keiser(MT), Klinedraw(WY), Moncha(NM), Oshoto(WY), Pulpit(CO), Roubideau(CO), Sharps(CO), Verde(CO), Wetherill(NM), and Wiley(CO) series. Amal and Elpedro soils receive higher amounts of winter precipitation. In addition, Amal soils have calcic horizons below 40 inches and Elpedro soils are weathered from limestone and are dominated by silt loam and silty clay loam textures. Chita soils have igneous parent materials and do not have buried horizons. Buick, Keiser, Klinedraw, Oshoto, and Wiley soils are more moist in the late spring and early summer (May and June) and dry in late summer in the soil moisture control section. Chevelon soils are moderately deep to bedrock and do not have secondary carbonates within the profile. Moncha soils have silt loam and silty clay loam textures and do not have accumulations of secondary carbonates. Pulpit, Roubideau, and Verde soils are moderately deep to a lithic contact. Sharps soils are moderately deep to a paralithic contact. Wetherill soils receive higher amounts of winter precipitation and have calcic horizons below 40 inches.
One of the above series currently listed as a competitor is the Chita(NM) series. Chita soils have calcic horizons within 40 inches and should be reclassified in the Calcidic subgroup.
GEOGRAPHIC SETTING: Altega soils are on summits and shoulders of interfluves on undulating plateaus and on fan aprons. They formed in Triassic and Permian age eolian material and alluvium derived from sandstone and shale. Slopes are 3 to 10 percent. Elevation ranges from 6,500 to 7,900 feet. The mean annual precipitation is 14 to 16 inches with about 45 percent falling as rain from high-intensity convective thunderstorms between July and September. The mean annual air temperature is 46 to 48 degrees F. The frost-free period is 120 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aliante, Altezita, Esquila, Estrada, Sabroso and Verano soils. Aliante soils have a mollic epipedon and occur on toeslopes and footslopes of undulating plateaus. Altezita soils are loamy, are very shallow, and occur on beveled summits. Estrada soils have a thick mollic epipedon and occur on footslopes and toeslopes. Esquila soils are clayey, shallow to sandstone bedrock, and occur on toeslopes of plateaus. Sabroso soils are loamy-skeletal and occur on steep south-facing backslopes. Verano soils are loamy-skeletal, have a mollic epipedon, and occur on steep north-facing backslopes.
DRAINAGE AND PERMEABILITY: Well drained; medium surface runoff; moderately slow permeability in the subsoil and moderately rapid permeability in the substratum.
USE AND VEGETATION: Altega soils are used for urban development, livestock grazing, and recreation. Present vegetation is blue grama, sand dropseed, bottlebrush squirreltail, june grass, western wheatgrass, cheatgrass, broom snakeweed, scattered walking stick cholla, and scattered Rocky Mountain juniper, and two-needle pinyon.
DISTRIBUTION AND EXTENT: Altega soils are of small extent on the northern Glorieta Slope part of the Pecos Valley section of the Great Plains physiographic province in northcentral New Mexico. The MLRA is 70A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona.
SERIES PROPOSED: Santa Fe County, New Mexico; Santa Fe Area Soil Survey Update; 2000. Altega is a local place name.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 2 inches (A horizon)
Argillic horizon - 2 to 58 inches (Bt horizons)
Lithic contact - 101 inches (top of 2R layer)
Classified according to Keys to Soil Taxonomy Tenth Edition, 2006.
ADDITIONAL DATA: The series type location was sampled for the National Soil Survey Laboratory (NSSL), Lincoln, NE, as soil survey sample number S99NM-049-8. Reference analyses such as particle-size distribution, organic carbon content, and cation exchange capacity were performed.