LOCATION HOLLOMEX                NM+TX

Established Series
Rev. CDL-RJA-LWH-ACT
08/2012

HOLLOMEX SERIES

The Hollomex series consists of very deep, well drained, moderately permeable soils that formed in loamy calcareous and gypsiferous sediments. The soils are on hillslopes, valley floors, and terraces. Slope ranges from 0 to 10 percent. Mean annual precipitation is about 12 inches and mean annual air temperature is about 62 degrees F.

TAXONOMIC CLASS: Fine-gypseous, hypergypsic, thermic Ustic Haplogypsids

TYPICAL PEDON: Hollomex loam--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 2 inches; light brown (7.5YR 6/4) loam, brown (7.5YR 5/4) moist; weak medium platy structure; soft, very friable, slightly sticky and slightly plastic; common fine roots; common very fine pores; strongly effervescent; slightly alkaline (pH 7.8); abrupt smooth boundary.

A2--2 to 5 inches; light brown (7.5YR 6/4) loam, brown (7.5YR 4/4) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; common very fine pores; few fine soft masses and filaments of calcium carbonate; strongly effervescent; moderately alkaline (pH 8.4); abrupt wavy boundary. (Combined thickness of A horizons are 1 to 10 inches)

Ckyy1--5 to 10 inches; very pale brown (10YR 8/3) gypsiferous loam, very pale brown (10YR 7/3) moist; massive; slightly hard, friable, slightly sticky and nonplastic; few very fine roots; common very fine pores; common medium soft masses of calcium carbonate; strongly effervescent; neutral (pH 7.2); clear wavy boundary. (4 to 20 inches thick)

Ckyy2--10 to 60 inches; pale yellow (2.5Y 8/4) gypsiferous loam, pale yellow (2.5Y 7/4) moist; massive; slightly hard, friable, slightly sticky and nonplastic; few very fine roots; common medium masses of calcium carbonate; strongly effervescent; neutral (pH 7.2).

TYPE LOCATION: Chaves County, New Mexico; 2,490 feet north and 528 feet east of the southwest corner, sec. 27, T. 10 S., R. 26 E., lat. 33 degrees 24 minutes 58 seconds N., long. 104 degrees 17 minutes 32 seconds W.

RANGE IN CHARACTERISTICS:

Soil Moisture: Intermittently moist in some part of the SMCS December through March and June through September.

Soil Temperature: 59 to 63 degrees F.

Depth to the hypergypsic: 0 to 10 inches

Rock fragments: less than 5 percent

Gypsum content: greater than 40 percent

Organic carbon (upper 40 cm): less than 0.4 percent

Control section: apparent textures have 18 to 35 percent clay and more than 15 percent fine sand or coarser

A horizon
Hue: 5YR to 10YR
Value: 4 to 7 dry, 3 to 5 moist
Chroma: 1 to 4, dry or moist
Texture: loam, silt loam, sandy clay loam, clay loam, sandy loam, fine sandy loam

Ayy, Cyy, or Ckyy horizons
Hue: 2.5YR to 2.5Y
Value: 6 to 8 dry, 3 to 7 moist
Chroma: 1 to 6, dry or moist
Texture: gypsiferous loam, gypsiferous silt loam, gypsiferous sandy clay loam, gypsiferous clay loam, gypsiferous sandy loam, gypsiferous fine sandy loam

Consistence: Soft to hard. Material is often hard and firm in place, but easily crushed when removed. More than 85 percent of the material slakes in water.

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Hollomex soils are on hillslopes, valley floors, and terraces. They formed in sediments derived from loamy calcareous gypsiferous rocks. Slopes range from 0 to 10 percent. The mean annual precipitation ranges from 12 to 16 inches. The mean annual air temperature ranges from 57 to 67 degrees F. The frost-free period ranges from 210 to 250 days. Elevation ranges from 4,000 to 5,500 feet.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Elcor, Pokorny, Walkerwells, Hollebeke, and Joberanch soils. Elcor soils are on low hills. Pokorny soils are on paleoterraces. Walkerwells soils are on flood plains. Hollebeke soils have a petrogypsic horizon and are shallow to bedrock and are in similar positions as the Elcor soils. Joberanch soils have a petrogypsic horizon and a silicate cap and are in similar positions as the Pokorny soils.

DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate. Runoff is negligible on slopes less than 1 percent, very low on 1 to 3 percent slopes, low on 3 to 5 percent slopes, and medium on 5 to 10 percent slopes.

USE AND VEGETATION: Rangeland. Present vegetation includes gyp grama, alkali sacaton, black grama, coldenia, Mormon-tea, and other shrubs, grasses, and forbs.

DISTRIBUTION AND EXTENT: Southeastern and south-central New Mexico, and southwest Texas. MLRA 42. Hollomex soils are of moderate extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona

SERIES ESTABLISHED: Chaves County (North Part), New Mexico, 1981.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon: the zone from 0 to 5 inches (A horizon)

Gypsic horizon: the zone from 5 to 60 inches (Ckyy1 and Ckyy2 horizons)

Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Eleventh Edition, 2010

Revised for the correlation of Hudspeth County, Texas (Main Part) and Culberson County, Texas (Main Part); July, 2012, NMS

ADDITIONAL DATA: NSSL data on pedons S79NM-005-10 and S79NM-005-15.

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National Cooperative Soil Survey
U.S.A.