LOCATION DELPHOS                 NM

Established Series
TAC-TCB-RM
03/2016

DELPHOS SERIES

The Delphos series consists of very deep, well drained, moderately rapidly permeable soils. These soils formed in loamy calcareous eolian sediments in the Blackwater Draw Formation of Pleistocene age. Delphos soils are on nearly level to gently sloping plains in broad, shallow basins or draws. Slope ranges from 0 to 3 percent. Mean annual precipitation is 406 mm (16 in), and mean annual temperature is 16 degrees C. (61 degrees F).

TAXONOMIC CLASS: Coarse-loamy, siliceous, semiactive, thermic Ustic Haplocalcids

TYPICAL PEDON: Delphos loamy fine sand, on an east-facing, concave, 1 percent slope in rangeland at an elevation of about 1,299 m (4,262 ft). (Colors are for dry soil unless otherwise noted.)

A--0 to 14 cm (0 to 6 in); brown (7.5YR 5/4) loamy fine sand, brown (7.5YR 4/4) moist; weak medium subangular blocky structure; soft, very friable; nonsticky and nonplastic; common fine roots throughout; slightly alkaline; clear smooth boundary. (Thickness is 15 to 38 cm [6 to 15 in].)

Bw--14 to 30 cm (6 to 12 in); brown (7.5YR4/4) loamy fine sand, dark brown (7.5YR3/4) moist; moderate coarse subangular blocky structure; soft, very friable; nonsticky and nonplastic; common fine and a few coarse roots throughout; moderately alkaline; clear smooth boundary. (Thickness is 0 to 51 cm [0 to 20 in].)

2Bk1--30 to 48 cm (12 to 19 in); very pale brown (10YR 8/2) clay loam, light gray (10YR 7/2) moist; moderate medium subangular blocky structure; slightly hard, firm; moderately sticky and moderately plastic; common fine and medium roots throughout; about 55 percent calcium carbonate by volume as coarse masses and finely disseminated carbonates throughout; violently effervescent; moderately alkaline; clear smooth boundary. (Thickness is 25 to 64 cm [10 to 25 in].)

2Bk2--48 to 74 cm (19 to 29 in); light gray (10YR 7/2) sandy clay loam, pale brown (10YR 6/3) moist; moderate medium subangular blocky structure; slightly hard, friable; moderately sticky and moderately plastic; common fine and medium roots throughout; about 30 percent calcium carbonate by volume as fine masses and finely disseminated carbonates throughout; violently effervescent; strongly alkaline; clear smooth boundary.

2Bk3--74 to 92 cm (29 to 36 in); light gray (10YR 7/2) fine sandy loam, pale brown (10YR 6/3) moist; moderate coarse subangular blocky structure; soft, very friable; slightly sticky and slightly plastic; common fine and medium roots throughout; about 10 percent calcium carbonate by volume as fine masses and finely disseminated carbonates throughout; strongly effervescent; strongly alkaline; clear smooth boundary.

2Bk4--92 to 118 cm (36 to 46 in); light gray (10YR 7/2) fine sandy loam, light brownish gray (10YR 6/2) moist; weak coarse subangular blocky structure; soft, very friable; slightly sticky and slightly plastic; common fine and medium roots throughout; about 15 percent calcium carbonate by volume as medium masses and finely disseminated carbonates throughout; violently effervescent; strongly alkaline; clear smooth boundary.

2Bk5--118 to 156 cm (46 to 61 in); light gray (10YR 7/2) fine sandy loam, light brownish gray (10YR 6/2) moist; moderate coarse subangular blocky structure; soft, very friable; slightly sticky and slightly plastic; common very fine and fine roots throughout; about 20 percent calcium carbonate by volume as medium masses and finely disseminated carbonates throughout; violently effervescent; strongly alkaline; clear smooth boundary. (Combined thickness of the Bk horizons 88 to 126 cm [35 to 50 in].)

3Btk1--156 to 182 cm (61 to 72 in); light gray (10YR 7/2) fine sandy loam, light brownish gray (10YR 6/2) moist; moderate coarse prismatic structure parting to moderate medium subangular blocky; slightly hard, friable; slightly sticky and slightly plastic; common very fine and fine roots throughout; few faint discontinuous clay films on vertical faces of peds; about 5 percent calcium carbonate by volume as medium masses and finely disseminated carbonates throughout; violently effervescent; strongly alkaline; clear smooth boundary.

3Btk2--182 to 218 cm (72 to 86 in); 70 percent strong brown (7.5YR 5/6) and 30 percent pinkish gray (7.5YR 7/2) sandy clay loam, 70 percent strong brown (7.5YR 4/6) and 30 percent pinkish gray (7.5YR 6/2) moist; moderate coarse prismatic structure parting to moderate medium subangular blocky; hard, firm; moderately sticky and moderately plastic; common very fine and fine roots throughout; few faint discontinuous clay films on vertical faces of peds; about 20 percent organic stains and coatings on vertical faces of peds; about 5 percent calcium carbonate by volume as fine masses lining pores; slightly effervescent; strongly alkaline.

TYPE LOCATION: Roosevelt County, New Mexico; from the intersection of Highway 458 and Highway 206 near Pep; 6.3 miles south on Highway 206 to Roosevelt County Road 34 S.; 4 miles west on Roosevelt County Road 34 S. to private road; 2.5 miles south on private road; 50 ft south in rangeland; NW of the SW of Section 7, T. 7 S., R. 35 E. of Section 7, Township 7 S, Range 35 E. Latitude: 33 degrees, 43 minutes, 21.7 seconds N; Longitude: 103 degrees, 24 minutes, 30.9 seconds W; Krider, New Mexico USGS quad; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: An aridic moisture regime bordering on ustic. The soil moisture control section is dry in some or all parts for more than 205 but less than 270 days, cumulative, in normal years. November through April normally are the driest months. These soils are intermittently moist in May through October.
Mean annual soil temperature: 15 to 18 degrees C. (59 to 64 degrees F).
Depth to secondary calcium carbonate: 0 to 51 cm (0 to 20 in).
Depth to calcic horizon: 25 to 102 cm (10 to 40 in).
Particle-size control section (weighted average): less than 18 percent silicate clay
Solum thickness: more than 203 cm (80 in).

A horizon:
Hue: 7.5YR or 10YR
Value: 5 to 7, 4 or 6 moist
Chroma: 2 to 6
Texture: fine sand, loamy fine sand
Effervescence: none to strong
Reaction: slightly alkaline or moderately alkaline

Bw horizon:
Hue: 7.5YR or 10YR
Value: 5 to 7, 4 or 6 moist
Chroma: 2 to 6
Texture: fine sand, loamy fine sand, fine sandy loam
Visible secondary carbonates: less than 2 percent by volume fine masses and finely disseminated carbonates
Effervescence: none to strong
Reaction: slightly alkaline or moderately alkaline

2Bk horizons:
Hue: 7.5YR to 10YR
Value: 6 to 8, 5 to 7 moist
Chroma: 1 to 4
Texture: fine sandy loam, sandy clay loam, clay loam
Visible secondary calcium carbonate: 5 to 50 percent by volume as masses, nodules, and finely disseminated carbonates
Rock fragments: 0 to 10 percent, gravel size, very strongly cemented carbonate nodules
Calcium carbonate by weight: 3 to 40 percent
Effervescence: strong or violent
Reaction: moderately alkaline or strongly alkaline

3Btk horizons:
Hue: 5YR to 7.5YR
Value: 5 to 7, 4 to 6 moist
Chroma: 2 to 6
Texture: fine sandy loam, sandy clay loam
Visible secondary calcium carbonate: 3 to 30 percent by volume as masses, nodules, and finely disseminated carbonates
Rock fragments: 0 to 10 percent, gravel size, very strongly cemented carbonate nodules
Calcium carbonate by weight: 2 to 20 percent
Effervescence: slight to violent
Reaction: moderately alkaline or strongly alkaline

COMPETING SERIES: There are no competing series in the same family. Similar soils include the Agudo (T-NM), Lovington (T-NM), Malstrom, Milsand, Penwell, Ratliff and Tornero (T-NM) series.
Agudo soils: have more than 18 percent silicate clay in the particle-size control section, contain more than 40 percent calcium carbonate are dry in the soil moisture control section for slightly longer periods.
Lovington, Ratliff, and Tornero series: have more than 18 percent silicate clay in the particle-size control section.
Malstrom soils: are dry in the soil moisture control section for slightly longer periods.
Milsand series: have sandy particle-size control section and are moist in the soil moisture control section for longer periods.
Penwell series: have sandy particle-size control section and do not have a calcic horizon.

GEOGRAPHIC SETTING:
Parent material: sandy and loamy, calcareous eolian deposits from the Blackwater Draw Formation of Pleistocene age.
Landform: nearly level to gently sloping, concave plains or broad, shallow basins or draws.
Slope: 0 to 3 percent.
Mean annual air temperature: 14 to 17 degrees C. (57 to 63 degrees F).
Mean annual precipitation: 356 to 432 mm (14 to 17 in).
Frost-free period: 180 to 220 days.
Elevation: 762 to 1402 m (2,500 to 4,600 ft).
Thornthwaite annual P-E Index Values: 22 to 26.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the similar Ratliff series and also the Amarose (NM), Elida (NM), Jalmar, and Vestwells (NM) series.
Amarose, Elida, Jalmar, and Vestwells soils: are on similar or slightly higher landscape positions and have argillic horizons.
Ratliff soils: are on similar landscape positions.

DRAINAGE AND PERMEABILITY: Well drained and moderately rapid permeability. Surface runoff is negligible on less than 1 percent slopes and very low on 1 to 3 percent slopes.

USE AND VEGETATION: These soils are used primarily for rangeland. Native climax vegetation is tall and mid grasses, with tall grasses tending to dominate. This site is dominated by little bluestem and sand bluestem along with taller dropseed species. The remainder is mid and short grasses such as sideoats grama, sand dropseed, hooded windmillgrass, sand lovegrass, sand paspalum, fall witchgrass, hairy grama, needle and thread, and perennial threeawn. Sand sage, shinoak, and skunkbush are also present. This soil has been correlated to the Sandy (R077DY046TX) range site in MLRA-77D.

DISTRIBUTION AND EXTENT: Southern High Plains, Southwestern Part (MLRA 77D in LRR H) of eastern New Mexico. The series is moderately extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas

SERIES ESTABLISHED: MLRA-77 Soil Survey Update; Roosevelt County, New Mexico, 2014.

REMARKS: These soils were previously included with the Gomez series. Gomez soils have an aridic-ustic soil moisture regime.

Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon: 0 to 14 cm (0 to 6 in) A horizon.
Cambic horizon: 14 to 30 cm (6 to 12 in) Bw horizon.
Calcic horizon: 30 to 156 cm (12 to 61 in) 2Bk horizons.
Argillic horizon: 156 to 218 cm (11 to 86 in) 3Btk horizons.
Lithologic Discontinuity: 30 to 218 cm (12 to 86 in) 2Bk and 3Btk horizons.

ADDITIONAL DATA: NSSL - S08NM041004 (Roosevelt County, New Mexico).

Taxonomic Version: Keys to Soil Taxonomy, Twelfth Edition, 2014.

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National Cooperative Soil Survey
U.S.A.