LOCATION PONCIANO NMEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, mesic Ustic Haplocambids
TYPICAL PEDON: Ponciano very bouldery clay loam--on a west facing, convex slope of 29 percent at 6,000 feet elevation--rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 3 inches; reddish brown (5YR 4/4) very bouldery clay loam, dark reddish brown (5YR 3/4) moist; weak thin platy and moderate very fine granular structure; soft, very friable, sticky and plastic; common fine and very fine roots; 20 percent channers, 10 percent flagstones, 10 percent stones and 5 percent boulders; strongly effervescent; moderately alkaline; clear smooth boundary. (2 to 4 inches thick)
Bw--3 to 11 inches; reddish brown (2.5YR 4/4); channery silty clay loam, dark reddish brown (2.5YR 3/4) moist; moderate medium subangular blocky structure; hard, friable, sticky and plastic; few coarse and medium, common fine and many very fine roots; common very fine discontinuous irregularly shaped pores; 15 percent channers and 5 percent pebbles; strongly effervescent; calcium carbonates coat undersides of rock fragments and are segregated in few fine irregularly shaped seams; moderately alkaline; clear smooth boundary. (8 to 18 inches thick)
Bk1--11 to 24 inches; reddish brown (2.5YR 5/4) channery silty clay loam, reddish brown (2.5YR 4/4) moist; weak coarse subangular blocky structure; hard, friable, sticky and plastic; few coarse and medium, common fine and many very fine roots; common very fine discontinuous irregularly shaped pores; 20 percent channers and 5 percent pebbles; strongly effervescent; calcium carbonates completely coat rock fragments and are segregated in common medium irregularly shaped seams and filaments; strongly alkaline; clear wavy boundary. (10 to 20 inches thick)
Bk2--24 to 35 inches; reddish brown (2.5YR 5/4) channery silty clay loam, reddish brown (2.5YR 4/4) moist; moderate coarse subangular blocky structure; very hard, firm, sticky and plastic; common fine and very fine roots; common very fine discontinuous irregularly shaped pores; 15 percent channers and 5 percent pebbles; strongly effervescent; calcium carbonates completely coat rock fragments and are segregated in common fine irregularly shaped seams and filaments; strongly alkaline; clear smooth boundary. (9 to 20 inches thick)
Bk3--35 to 42 inches; reddish brown (2.5YR 4/4) silty clay loam, dark red (2.5YR 3/6) moist; weak coarse subangular blocky structure; hard, friable, sticky and plastic; few fine and very fine roots; few very fine discontinuous irregularly shaped pores; 20 percent soft angular mudstone fragments; 5 percent channers and 5 percent pebbles; strongly effervescent; calcium carbonates segregated in few fine irregularly shaped filaments and in pores; moderately alkaline; clear smooth boundary. (0 to 13 inches thick)
Bk4--42 to 60 inches; reddish brown (2.5YR 4/4) silty clay loam, dark red (2.5YR 3/6) moist; weak medium and coarse subangular blocky structure; hard, friable, sticky and plastic; few fine and very fine roots; few very fine discontinuous irregularly shaped pores; 40 percent soft angular mudstone fragments, 5 percent channers and 5 percent pebbles; strongly effervescent; calcium carbonates segregated in few fine irregularly shaped filaments and in pores; moderately alkaline (pH 8.4).
TYPE LOCATION: Socorro County, New Mexico; 22 miles east of Bernardo; east of gravel road to radio tower; 1,250 feet north and 900 feet west of the southeast corner of section 7, T. 2N R. 5 E.
RANGE IN CHARACTERISTICS:
Percent clay: 35 to 50 percent
Percent calcium carbonate equivalence: 5 to 15 percent throughout the profile
Profile reaction: moderately to strongly alkaline
Salinity (dS/m): 4 to 8
Soil moisture: Typically, the soil moisture control section is
intermittently moist in some part from July to September following
convective storms
A horizon:
Hue: 2.5YR or 5YR
Value: 4 dry, 3 moist
Chroma: 4
Texture: very bouldery clay loam or very stony silty clay loam
Bw and upper Bk horizons:
Hue: 2.5YR or 5YR
Value: 3 to 5 dry, 3 or 4 moist
Chroma: 4 to 6 moist or dry
Texture: channery silty clay loam or channery silty clay
Lower Bk horizons:
Hue: 2.5YR or 5YR
Value: 3 to 5 dry, 3 or 4 moist
Chroma: 4 to 6 dry or moist
Texture: silty clay or silty clay loam
Percent rock fragments: 0 to 5 pebbles, 0 to 10 channers
Percent soft fragments: 15 to 50 mudstone and shale
COMPETING SERIES: There are no competing series in the same family. Similar soils are the Camino, Gish (T), Litle, and Losmarios series. All of these series have active cation exchange activity class. In addition, Camino soils have a paralithic contact between 40 and 60 inches of the surface. Gish soils receive winter precipitation, Litle soils have a paralithic contact between 20 and 40 inches of the surface, and Losmarios soils have hue 7.5YR or yellower.
GEOGRAPHIC SETTING: Ponciano soils are on hillslopes below mesa escarpments and structural benches and on cuesta scarp faces. Ponciano soils formed in colluvium and alluvium derived from sandstones and mudstones. Slope ranges from 15 to 60 percent The average annual precipitation ranges from 10 to 13 inches and the average annual temperature ranges from 52 to 57 degrees F. The average frost-free period ranges from 160 to 180 days. Elevation ranges from 5,600 to 6,600 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Creel, Clovis, Deama, Harvey, La Fonda, Musofare, and Winona soils. Creel and Musofare soils are moderately deep to soft siltstone bedrock. Clovis, Harvey and La Fonda soils are in a fine-loamy family. Deama and Winona soils are shallow to limestone bedrock.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is slow. Runoff is very high.
USE AND VEGETATION: Ponciano soils are used for livestock grazing. Present vegetation is sideoats grama, black grama, galleta, Stipa spp., sacahuista, oneseed juniper and scattered pinyon.
DISTRIBUTION AND EXTENT: Ponciano soils are moderately extensive in central New Mexico. (see remarks section)
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Socorro County, New Mexico, 1984.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: 0 to 3 inches. (A horizon)
Cambic horizon: 3 to 11 inches. (Bw horizon)
Salinity values were determined on the type location and one other pedon with a Wheatstone bridge. The remaining pedons are estimated to have similar values. There may be less than 10,000 acres of this series recognized in the Socorro County Area survey, but it is estimated that many more acres of this soil exist in surrounding areas. Landscapes that this soil occurs on in adjacent survey areas were mapped in the past as miscellaneous land types such as rock land, steep rock land and shale rock land. (Valencia County, Eastern Part, Torrance Area and the White Sands Missile Range survey)