LOCATION AGUDO NM

Tentative Series
TAC-TCB
01/2014

AGUDO SERIES

The Agudo series consists of very deep, well drained, moderately slowly permeable soils that formed in moderately fine textured calcareous alluvium derived from siltstone, shale and sandstone. These soils are on alluvial fan terraces, valley side slopes and playa slopes. Slope ranges from 0 to 10 percent. Mean annual precipitation is 356 mm (14 in), and mean annual temperature is 15 degrees C. (59 degrees F).

TAXONOMIC CLASS: Fine-loamy, carbonatic, thermic Ustic Haplocalcids

TYPICAL PEDON: Agudo sandy clay loam, on a northwest-facing, concave, 1 percent slope in rangeland at an elevation of about 1,272 m (4,172 ft). (Colors are for dry soil unless otherwise noted.)

A--0 to 25 cm (0 to 10 in); brown (7.5YR 5/3) sandy clay loam, brown (7.5YR 4/3) moist; weak medium subangular blocky structure; soft, very friable; slightly sticky and slightly plastic; common fine roots throughout; about 20 percent calcium carbonate by volume as finely disseminated carbonates throughout; strongly effervescent; moderately alkaline; clear smooth boundary. (Thickness is 10 to 30 cm [4 to 12 in]).

Bk1--25 to 49 cm (10 to 19 in); brown (7.5YR5/3) sandy clay, dark brown (7.5YR4/3) moist; weak medium subangular blocky structure; soft, very friable; moderately sticky and moderately plastic; common fine and medium roots throughout; about 25 percent calcium carbonate by volume as medium masses, medium nodules and finely disseminated carbonates throughout; strongly effervescent; moderately alkaline; clear wavy boundary.

Bk2--49 to 81 cm (19 to 32 in); white (10YR 8/1) clay, light gray (10YR 7/2) moist; moderate medium subangular blocky structure; slightly hard, friable; moderately sticky and moderately plastic; common fine and medium roots throughout; about 40 percent calcium carbonate by volume as medium masses and finely disseminated carbonates throughout; violently effervescent; moderately alkaline; clear wavy boundary. (Combined thickness is 45 to 105 cm [18 to 41 in]).

Bkk--81 to 148 cm (32 to 58 in); white (2.5YR 8/1) clay, light gray (2.5Y 7/1) moist; moderate medium prismatic parting to moderate medium subangular blocky structure; slightly hard, friable; moderately sticky and moderately plastic; common fine and medium roots throughout; about 60 percent calcium carbonate by volume as medium masses, medium nodules and finely disseminated carbonates throughout; violently effervescent; strongly alkaline; clear wavy boundary. (Thickness is 51 to 102 cm [20 to 40 in]).

2BCk--148 to 203 cm (58 to 80 in); pale yellow (2.5Y 8/2) clay, light gray (2.5Y 7/2) moist; moderate medium subangular blocky structure; slightly rigid, moderately hard; moderately sticky and moderately plastic; common fine and medium roots throughout; about 28 percent calcium carbonate by volume as finely disseminated carbonates throughout; about 15 percent yellow (2.5Y 7/8) iron depletions; slightly effervescent; moderately alkaline.

TYPE LOCATION: Roosevelt County, New Mexico; from the intersection of Highway 60 and 84 and Roosevelt County road BA in Tolar; 1.5 miles south on Roosevelt County road BA; 0.6 miles west on Roosevelt County road 12N; 495 ft south in rangeland; NW1/4 of the SW1/4 of Section 7, Township 2 S, Range 29 E. Latitude: 34 degrees, 25 minutes, 44 seconds N; Longitude: 103 degrees, 56 minutes, 34 seconds W; Tolar, 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 17 degrees C. (59 to 63 degrees F).
Depth to secondary calcium carbonate: 25 to 50 cm (10 to 20 in.).
Depth to calcic horizon: 25 to 50 cm (10 to 20 in.).
Particle-size control section (weighted average): more 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 4
Texture: loamy fine sand, fine sandy loam, sandy clay loam
Effervescence: slight to strong
Reaction: slightly alkaline or moderately alkaline

Bw horizon (where present):
Hue: 7.5YR or 10YR
Value: 5 to 7, 4 or 6 moist
Chroma: 2 to 4
Texture: fine sandy loam, loam, sandy clay loam, clay loam
Visible secondary carbonates: less than 2 percent by volume fine masses and finely disseminated carbonates
Effervescence: slight to strong
Reaction: slightly alkaline or moderately alkaline

Bk horizons:
Hue: 7.5YR to 2.5Y
Value: 5 to 8, 4 to 7 moist
Chroma: 1 to 4
Texture: sandy clay loam, sandy clay, clay loam, clay
Visible secondary calcium carbonate: 5 to 50 percent by volume as masses, nodules, and finely disseminated carbonates
Calcium carbonate by weight: 3 to 40 percent
Effervescence: strong or violent
Reaction: moderately alkaline or strongly alkaline

Bkk horizons:
Hue: 10YR to 2.5Y
Value: 6 to 8, 5 to 8 moist
Chroma: 1 to 4
Texture: sandy clay loam, sandy clay, loam, clay loam, clay
Visible secondary calcium carbonate: 50 to 80 percent by volume as masses, nodules, and finely disseminated carbonates
Calcium carbonate by weight: 3 to 60 percent
Effervescence: violent
Reaction: moderately alkaline or strongly alkaline

2BC horizons:
Hue: 10YR to 2.5Y
Value: 6 to 8, 5 to 8 moist
Chroma: 1 to 4
Texture: fine sandy loam, sandy clay loam, sandy clay, clay
Visible secondary calcium carbonate: 5 to 50 percent by volume as masses, nodules, and finely disseminated carbonates
Calcium carbonate by weight: 3 to 40 percent
Effervescence: violent
Reaction: moderately alkaline or strongly alkaline

COMPETING SERIES: These are the Armesa, Cesario, Fizzleflat and Karro series in the same family. Similar soils include the Evanola, Malstrom, Ima, and Gallen series.
Armesa soils: are dry in the soil moisture control section for a slightly longer period.
Cesario soils: formed in residuum derived of Cretaceous age and are dry in the soil moisture control section for a longer period.
Fizzleflat soils: have a paralithic contact between 50 and 100 cm (20 and 40 in.) of the soil surface and are dry in the soil moisture control section for a longer period.
Karro soils: have a paralithic contact within 150 cm (60 in.) of the soil surface and are dry in the soil moisture control section for a longer period.
Evanola soils: have an argillic horizon that extends to 200 cm (79 in)or more.
Malstrom soils: have less than 18 percent silicate clay in the soil particle-size control section.
Ima soils: have less than 18 percent silicate clay in the soil particle-size control section and do not have a calcic horizon.
Gallen soils: have more than 15 percent coarse fragments in the particle-size control section.

GEOGRAPHIC SETTING:
Parent material: formed in moderately fine textured calcareous alluvium derived from siltstone, shale and sandstone.
Landform: slightly convex alluvial fan terraces, valley side slopes and playa slopes.
Slope: 0 to 10 percent.
Mean annual air temperature: 14 to 16 degrees C. (57 to 61 degrees F).
Mean annual precipitation: 305 to 406 mm (12 to 16 in.).
Frost-free period: 180 to 220 days.
Elevation: 1,097 to 1,615 m (3,600 to 5,300 ft).
Thornthwaite annual P-E Index Values: 22 to 26.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the similar Berwolf, Evanola (NM), Kolar, Neso and Redona series.
Berwolf, Evanola and Redona soils: are on higher landscape positions and have argillic horizons.
Kolar and Neso soils: are on higher landscape positions and have petrocalcic horizons.

DRAINAGE AND PERMEABILITY: Well drained and moderately slow permeability. Surface runoff is very low on less than 1 percent slopes, low on 1 to 3 percent slopes, medium on 3 to 5 percent slopes and high on 5 to 10 percent slopes.

USE AND VEGETATION: These soils are used primarily for rangeland. Native climax vegetation is mid and short grasses, with mid grasses tending to dominate. This site is dominated by blue grama. The remainder is mid and short grasses such as sideoats grama, sand dropseed, buffalograss, and perennial threeawn. Broom snakeweed, bullnettle, cholla and yucca are also present. This soil has been correlated to the Limy (R070BY068NM) ecological site in MLRA-70B.

DISTRIBUTION AND EXTENT: Upper Pecos River Valley (MLRA 70B in LRR G) of eastern New Mexico. The series is moderately extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: PHOENIX, ARIZONA

SERIES PROPOSED: MLRA-70 Soil Survey Update; Roosevelt County, New Mexico, 2011.

REMARKS: These soils were previously included with the Armesa series. Armesa better suited to southern New Mexico and are within MLRA 42.

Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon: 0 to 25 cm (0 to 10 in.) A horizon.
Calcic horizon: 25 to 203 cm (10 to 80 in.) Bk, Bkk and BCk horizons.
Lithologic Discontinuity: 148 to 203 cm (58 to 80 in.) 2BC horizon.

ADDITIONAL DATA: NSSL - S11NM041032 (Roosevelt County, New Mexico).

Taxonomic Version: Keys to Soil Taxonomy, Eleventh Edition, 2010.

National Cooperative Soil Survey
U.S.A.