LOCATION MCALLISTER              AZ+TX

Established Series
Rev. MLR/JEJ/PDC/CEM
07/2012

MCALLISTER SERIES

The McAllister series consists of very deep, well drained soils that formed in fan alluvium. McAllister soils are on fan terraces and have slopes of 0 to 25 percent. The mean annual precipitation is about 14 inches and the mean annual air temperature is about 63 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Ustic Calciargids

TYPICAL PEDON: McAllister loam - irrigated cropland. (Colors are for dry soil unless otherwise noted.)

Ap--0 to 12 inches; brown (10YR 5/3) loam, brown (7.5YR 4/2) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; many fine and few medium roots; many fine and very fine irregular pores; few fine gravel; strongly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (10 to 16 inches thick)

Bt1--12 to 16 inches; brown (7.5YR 5/4) clay loam, reddish brown (5YR 4/4) moist; weak fine subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many fine and few medium roots; common fine and very fine tubular pores; common faint clay films lining pores; few fine gravel; strongly effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (2 to 6 inches thick)

Bt2--16 to 24 inches; brown (7.5YR 5/4) clay loam, reddish brown (5YR 4/4) moist; moderate fine subangular blocky structure; very hard, friable, moderately sticky and moderately plastic; common fine roots; common fine irregular pores; common faint clay films on faces of peds; few fine gravel; strongly to violently effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (8 to 24 inches thick)

Btk--24 to 47 inches; light brown (7.5YR 6/4) clay loam, brown (7.5YR 5/4) moist; moderate fine angular blocky structure parting to moderate fine subangular; very hard, friable, moderately sticky and moderately plastic; few fine roots; many fine irregular and many fine and very fine tubular pores; many faint clay films and common black (10YR 2/1) manganese coatings on faces of peds; many medium and coarse petronodes; many fine and medium soft calcium carbonate masses; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (12 to 30 inches thick)

Bk--47 to 60 inches; light brown (7.5YR 6/4) fine sandy loam, brown (7.5YR 5/4) moist; massive; slightly hard, friable, slightly sticky and moderately plastic; few fine roots; many fine and very fine tubular pores; common manganese coatings lining pores; common medium and coarse petronodes; few fine soft calcium carbonate masses; strongly to violently effervescent; moderately alkaline (pH 8.2).

TYPE LOCATION: Cochise County, Arizona; 1,100 feet east and 1,660 feet north of the southwest corner of Section 10, T. 13 S., R. 24 E.

RANGE IN CHARACTERISTICS:

Soil Moisture: Intermittently moist in some part of the soil moisture control section during July - September and December - February. Driest during May and June. Ustic aridic soil moisture regime.

Soil Temperature: 60 to 69 degrees F.

Rock Fragments: Averages less than 30 percent in the control section; can range to 45 percent in any one subhorizon

Reaction: Neutral to moderately alkaline in the upper part and slightly or moderately alkaline in the lower part

Depth to calcic horizon: 20 to 40 inches. Calcium carbonate equivalent averages more than 15 percent

Organic matter: 1 percent or more in the surface

A or Ap horizons
Hue: 5YR, 7.5YR, 10YR
Value: 4 to 7 dry, 3 or 4 moist
Chroma: 2 to 6 dry, 2 to 4 moist

Bt or Btk horizons
Hue: 2.5YR, 5YR, 7.5YR
Value: 3 to 7, dry or moist
Chroma: 3 to 6 dry, 2 to 6 moist
Texture: sandy clay loam, sandy loam, coarse sandy loam, loam, clay loam (averages more than 18 percent clay)

Bk or C horizons
Hue: 2.5YR, 5YR, 7.5YR
Value: 5 to 8 dry, 4 to 6 moist
Chroma: 2 to 6, dry or moist

COMPETING SERIES: These are the Amarose (NM), Grizzle (AZ), Gulch (AZ), Headquarters (NM), McNeal (AZ), Redona (NM) and Tinney (NM) series. Amarose and Redona are moist in the soil moisture control section during May and June and occur in the Great Plains.

Headquarters, Gulch, Grizzle, and McNeal soils have calcic horizons above 20 inches.

Gulch soils have 1 to 4 percent gypsum.

Grizzle is moderately deep to paralithic contact.

Tinney soils have a cambic horizon above the argillic horizon.

GEOGRAPHIC SETTING: The McAllister soils are on fan terraces and have slopes of 0 to 25 percent. These soils formed in fan alluvium from mixed sources. Elevations range from 3,900 to 5,500 feet. The mean annual precipitation ranges from 12 to 16 inches. The mean annual air temperature ranges from 59 to 67 degrees F. The frost-free period is about 165 to 260 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Forrest, Karro and Tombstone soils. Forrest soils are fine textured. Karro and Tombstone soils do not have argillic horizons.

DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate or moderately slow permeability.

USE AND VEGETATION: McAllister soils are used for irrigated cropland, livestock grazing and wildlife habitat. The present vegetation is blue grama, curly mesquite, yucca, cacti and annual grasses.

DISTRIBUTION AND EXTENT: Southeastern Arizona and West Texas. This series is not extensive. MLRAs are 41 and 42.

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

SERIES ESTABLISHED: Cochise County (Sulphur Springs Valley Area), Arizona; 1948.

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

Ochric epipedon - The zone from 0 to 12 inches (Ap horizon)

Argillic horizon - The zone from 12 to 47 inches (Bt1, Bt2, Btk horizons)

Calcic horizon - The zone from 24 to 60 inches (Btk, Bk 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

---

National Cooperative Soil Survey
U.S.A.