LOCATION KHAPO NMEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Ustic Calciargids
TYPICAL PEDON: Khapo sandy loam--on a planar to gently convex toeslope of an erosional fan remnant sloping 7 percent to the southeast at 6,440 feet elevation--rangeland. (Colors are for dry soil unless otherwise noted. When described, the soil was dry from the surface to 3 inches, slightly moist from 3 to 60 inches, and dry below 60 inches.)
A--0 to 2 inches; brown (7.5YR 5/3) sandy loam, brown (7.5YR 4/2) 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; 5 percent gravel; neutral (pH 7.0); clear smooth boundary. (2 or 3 inches thick)
BA--2 to 5 inches; brown (7.5YR 5/3) sandy loam, brown (7.5YR 4/3) moist; moderate medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; few fine and common very fine roots; few very fine irregularly shaped pores; 5 percent gravel; slightly alkaline (pH 7.4); clear smooth boundary. (0 to 4 inches thick)
Bt--5 to 11 inches; brown (7.5YR 5/4) sandy clay loam, brown (7.5YR 4/4) moist; moderate coarse subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; few medium, few fine, and common very fine roots; few fine and few very fine tubular pores; few distinct clay films on faces of peds and lining pores and few faint clay bridges between coarse sand grains and rock fragments; 5 percent gravel; moderately alkaline (pH 7.9); clear smooth boundary. (4 to 14 inches thick)
Btk1--11 to 29 inches; light brown (7.5YR 6/4) fine sandy loam, brown (7.5YR 5/4) moist; weak medium prismatic structure parting to moderate coarse subangular blocky; slightly hard, friable, slightly sticky and nonplastic; few fine and common very fine roots; few fine and common very fine tubular pores; few 0.5 inch wide tubular cicada larvae burrows; common faint clay films on faces of peds and lining pores; 5 percent gravel; strongly effervescent, secondary calcium carbonate segregated as common fine and medium irregularly shaped coats on faces of peds and on rock fragments; moderately alkaline (pH 8.4); clear wavy boundary. (7 to 18 inches thick)
Btk2--29 to 43 inches; light brown (7.5YR 6/4) fine sandy loam, brown (7.5YR 5/4) moist; moderate coarse subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; few fine and common very fine roots; few fine and common very fine tubular pores; few faint clay films on faces of peds and lining pores; 5 percent gravel; strongly effervescent, secondary calcium carbonate segregated as few fine irregularly shaped coats on faces of peds and on rock fragments; strongly alkaline (pH 8.6); gradual smooth boundary. (10 to 30 inches thick)
Bk1--43 to 72 inches; light brown (7.5YR 6/4) fine sandy loam, brown (7.5YR 5/4) moist; weak coarse subangular blocky structure parting to moderate medium subangular blocky; slightly hard, very friable, slightly sticky and nonplastic; few fine and few very fine roots; few fine and few very fine tubular pores; 5 percent gravel; violently effervescent, secondary calcium carbonate segregated as few fine irregularly shaped coats on faces of peds and on rock fragments; strongly alkaline (pH 8.6); clear smooth boundary. (8 to 29 inches thick)
Bk2--72 to 89 inches; light brown (7.5YR 6/4) sandy loam, brown (7.5YR 5/4) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; few very fine roots; few fine and few very fine tubular pores; few thin lenses of gravelly sandy loam; 10 percent gravel; violently effervescent, secondary calcium carbonate segregated as common fine irregularly shaped coats on faces of peds and on rock fragments; strongly alkaline (pH 8.6); clear smooth boundary. (10 to 24 inches thick)
Bkb--89 to 120 inches; brown (7.5YR 5/2) loam, brown (7.5YR 4/3) moist; weak medium and moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine tubular pores; 5 percent gravel; strongly effervescent, secondary calcium carbonates segregated as few fine irregularly shaped coats on rock fragments and on faces of peds; moderately alkaline (pH 8.4).
TYPE LOCATION: Santa Fe County, New Mexico; about 4 miles west-northwest of Agua Fria; 1,900 feet south and 2,250 feet east of the northwest corner of section 27, T.17N., R.8E.; USGS Agua Fria 7.5 minute topographic quadrangle; Latitude 35 degrees 40 minutes 36 seconds North and Longitude 106 degrees 4 minutes 53 seconds West, NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture - The soil moisture control section is intermittently moist in some part from July to October and December to March. The soils are driest in May and June. The soil moisture regime is aridic bordering on ustic.
Mean annual soil temperature - 52 to 54 degrees F.
Depth to base of argillic horizon - 26 to 49 inches
Depth to calcareous material (as visible secondary calcium carbonate) - 6 to 17 inches
Depth to calcic horizon - 6 to 16 inches
Volcanic glass content - 1 to 5 percent in the coarse silt and very fine sand fractions
Oxalate extractable Al plus 1/2 Fe: less than 0.20
Lithology of rock fragments: granite, gneiss, and schist
Particle-size control section (weighted averages)
Silicate clay content: 12 to 18 percent
Sand content: 30 to 50 percent
Fine sand or coarser content: 25 to 45 percent
Rock fragment content: 0 to 10 percent gravel
Reaction - neutral to slightly alkaline in the surface; moderately alkaline to strongly alkaline in the subsoil and upper part of the substratum; moderately alkaline in the lower part of the substratum
A and BA horizons
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 or 3 moist
Texture: sandy loam or fine sandy loam
Other features: BA horizons are absent in pedons that have A horizons with value 3 moist
Bt horizon
Value: 4 or 5 dry, 4 moist
Chroma: 3 or 4, dry or moist
Texture: sandy clay loam, loam, or fine sandy loam
Btk horizons
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: fine sandy loam, loam, or sandy loam
Calcium carbonate equivalent: 5 to 10 percent
Salinity, mmhos/cm: 0 to 2
Sodicity, SAR: 0 to 4
Bk horizons
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: fine sandy loam, sandy loam, or loam
Rock fragments: 5 to 10 percent gravel
Calcium carbonate equivalent: 5 to 15 percent
Salinity, mmhos/cm: 2 to 4
Sodicity, SAR: 4 to 13
Other features: some pedons have texture of coarse sandy loam between 40 and 60 inches, or coarse sand or gravelly sandy loam below 60 inches
BCk and Bkb horizons (not in all pedons)
Value: 5 through 7 dry, 4 or 5 moist
Chroma: 2 through 4, dry or moist
Texture: loam, fine sandy loam, or sandy loam
Rock fragments: 5 to 15 percent gravel
Calcium carbonate equivalent: 2 to 5 percent
Salinity, mmhos/cm: 0 to 2
Sodicity, SAR: 0 to 4
Other features: some pedons have buried horizons with more than 15 percent calcium carbonate equivalent between 60 and 80 inches or unaltered layers of glassy volcanic ash below 80 inches
Ck and C horizons (present in stream terrace phase only)
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: stratified loam to gravelly coarse sand; some pedons have thin strata or lenses of cobbly coarse sand or cobbly loamy sand
Rock fragments: 5 to 35 percent gravel
Calcium carbonate equivalent: 2 to 5 percent
Salinity, mmhos/cm: 2 to 4
Sodicity, SAR: 0 to 4
COMPETING SERIES: At present, there are no other series in this family. Soil series presently classified as Ustic Haplargids or soil series with similar properties still classified as Ustollic or Ustalfic Haplargids are the Betonnie, Bijou, Gilcrest, Marjane, Neesopah, Palma, Terro, Terry, Tintero (T), Vonalee, and Windwhistle series.
Only the Windwhistle soil has a calcic horizon described within the series control section. Windwhistle soils are moderately deep to bedrock. Although not recognized as such, the Bk horizons of Palma soils may possibly qualify as calcic horizons. Palma soils are drier in the soil moisture control section between December and March and do not have significant amounts of volcanic glass.
GEOGRAPHIC SETTING: Khapo soils are on toeslopes of erosional fan remnants and treads of high stream terraces. They formed in alluvium derived from Precambrian granite, gneiss, and schist; Tertiary granitic sandstone and mudstone; and Quaternary loess and volcanic ash. Slopes are 0 to 8 percent. Elevation ranges from 5,500 to 6,800 feet. The mean annual precipitation is 10 to 13 inches with about 45 percent falling as rain from high-intensity convective thunderstorms between July and September. The mean annual air temperature is 50 to 52 degrees F. The frost-free period is 150 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chupe, Panky, Zepol, and Zozobra soils. Chupe soils are sandy, do not have diagnostic horizons, and occur on flood plains of valley floors. Panky soils are fine-loamy, have calcic horizons, and occur on adjacent summits of erosional fan remnants. Zepol soils are fine-silty, have thick mollic epipedons, and occur on adjacent narrow flood plains of valley floors. Zozobra soils are coarse-loamy over sandy or sandy-skeletal, have calcic horizons, and occur on shoulders of erosional fan remnants.
DRAINAGE AND PERMEABILITY: Well drained; low or medium surface runoff; moderate permeability.
USE AND VEGETATION: Khapo soils are used for urban development, livestock grazing, and recreation. Present vegetation is blue grama, ring muhly, sand dropseed, bottlebrush squirreltail, broom snakeweed, Bigelow rubber rabbitbrush, walkingstick cholla, and scattered oneseed juniper.
DISTRIBUTION AND EXTENT: Khapo soils are of small extent on the southeastern Espanola Basin part of the Basin and Range province in northcentral New Mexico. The MLRA is 36.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Santa Fe County, New Mexico; Santa Fe Area Soil Survey Update; 2008. Khapo is the local Indian name of the Santa Clara Indian Pueblo.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 5 inches. (A and BA horizons)
Argillic horizon - The zone from 5 to 43 inches. (Bt, Btk1, and Btk2 horizons)
Calcic horizon - The zone from 11 to 89 inches. (Btk1, Btk2, Bk1, and Bk2 horizons)
Particle-size control section - The upper 20 inches of the argillic horizon, 5 to 25 inches (Bt and part of the Btk1 horizon)
Series control section - The zone from 0 to 80 inches.
Note: This soil has minor amounts of volcanic glass in the coarse silt and very fine sand fractions. It is assumed that most of the volcanic glass derived from nearby Pleistocene ash eruptions has altered to more stable minerals like chalcedony. In addition, Lincoln lab data from adjacent soils indicates that ammonium oxalate extractable aluminum and iron percentages are very low. It is estimated that Khapo soils have similar values and thus do not have the properties of the andic intergrades.
ADDITIONAL DATA: The series type location has been sampled for the Soil Survey Laboratory (SSL), Lincoln, NE as soil survey sample number S94NM-049-003. Reference analyses such as particle-size distribution, cation exchange capacity, and optical grain counts were performed.
Classified according to Keys to Soil Taxonomy, Tenth Edition, 2006.