LOCATION KIMBROUGH          NM+TX

Established Series
Rev. RAH-TCB-ACT
01/2000

KIMBROUGH SERIES

The Kimbrough series consists of soils that are very shallow to shallow to a petrocalcic horizon. They are well drained, calcareous, gravelly soils that formed in moderately fine textured eolian sediments of the Blackwater Draw Formation of Pleistocene age. These soils are typically on gently sloping plains, narrow ridges, and side slopes along draws. Slope ranges from 0 to 3 percent. Mean annual precipitation is 15 inches, and mean annual temperature is 63 degrees F.

TAXONOMIC CLASS: Loamy, mixed, superactive, thermic, shallow Ustic Petrocalcids

TYPICAL PEDON: Kimbrough gravelly loam, in rangeland at an elevation of about 3,900 feet. (Colors are for dry soil unless otherwise stated.)

A1--0 to 2 inches; dark grayish brown (10YR 4/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; weak thin platy structure; slightly hard, friable, sticky and slightly plastic; many fine roots; many fine irregular pores; about 15 percent of the surface covered with caliche fragments; 10 percent pebble size and 5 percent cobble size calcium carbonate fragments; strongly effervescent, calcium carbonate disseminated; moderately alkaline (pH 7.8); abrupt smooth boundary. (1 to 5 inches thick)

A2--2 to 8 inches; dark grayish brown (10YR 4/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; weak granular and subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine roots; many fine irregular pores; 20 percent pebble size and 10 percent cobble size calcium carbonate fragments; strongly effervescent, calcium carbonate is disseminated and occurs in threads and masses; moderately alkaline (pH 7.8); abrupt smooth boundary. (2 to 12 inches thick)

Bkm--8 to 36 inches; white (N 8/) indurated layer containing a few fractures; laminar in upper part, with indurated to strongly cemented calcium carbonate with pea-shaped calcitic structures (pisolites) below the laminae; becomes softer with depth. (5 to 40 inches thick)

Bk--36 to 80 inches; white (10YR 8/1); massive; soft calcium carbonate soil material with a loam texture; 15 percent strongly cemented caliche fragments, 25 percent moderately cemented caliche fragments; most caliche fragments have a laminar cap 1 to 2 mm thick; violently effervescent.

TYPE LOCATION: Lea County, New Mexico; 5 miles southeast of Lovington on New Mexico Highway 18, then 0.25 mile northeast, 0.5 mile north, 0.5 mile east on north side of road, or 1000 feet north and 1000 feet west corner of Sec 30, T. 16 S., R. 37 E; Latitude: 32 degrees, 53 minutes, 15 seconds N; Longitude: 103 degrees, 11 minutes, 27 seconds W; Humble City NW, New Mexico USGS quad; NAD 27.

RANGE IN CHARACTERISTICS:
Soil moisture: An aridic moisture regime bordering on ustic. The soil moisture control section is dry in all parts for 150 to 225 days, cumulative, in normal years. The soil is intermittently moist July through October. December through February are the driest months.
Mean annual soil temperature: 59 to 67 degrees F.Depth to petrocalcic horizon: 4 to 20 inches.Solum thickness: 4 to 20 inches.Particle-size control section: 15 to 20 percent silicate clay.
A horizon:Hue: 7.5YR or 10YR
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 2 to 4
Texture: loam, fine sandy loam, gravelly loam, gravelly fine sandy loam
Calcium carbonate equivalent: 0 to 5 percent
Effervescence: strong to violent
Reaction: slightly to moderately alkaline

Bkm horizon:
This horizon ranges from fractured, indurated, and thin to thickly laminar to continuously indurated, thickly laminar. Some pedons have indurated to moderately cemented pea-shaped, calcitic structures below the laminar caps (pisolitic structure).

Bk horizon:
Hue: 7.5YR or 10YR
Value: 7 or 8 dry, 6 or 7 moist
Chroma: 1 to 4
Coarse fragments: 25 to 60 percent imbedded in soil matrix
Texture: loam
Calcium carbonate equivalent: more than 40 percent
Effervescence: violent
Reaction: moderately alkaline

COMPETING SERIES: These are the Blakeney (TX), Conger (TX), and Kolar (NM) series.
Blakeney and Kolar soils: do not have mollic colors in the surface horizon.
Conger soils: average greater than 18 to 20 percent clay in the particle size control section.

GEOGRAPHIC SETTING:
Parent material: a thin mantle of medium to moderately coarse textured eolian sediments over an indurated layer.
Landform: level to gently sloping plains with common shallow depressions.
Slope: 0 to 3 percent.
Elevation: 3,600 to 4,600 feet.
Mean annual air temperature: 57 to 65 degrees F.
Mean annual precipitation: 10 to 17 inches.
Frost-free period: 175 to 215 days.
Thornthwaite annual P-E Index: 22 to 32

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Amarose, Arizer, Lea, Sharvana, and Simona soils.
Amarose and Arizer soils: do not have a petrocalcic horizon, and occur on slightly lower landscape positions.
Lea soils have a petrocalcic horizon more than 20 inches from the soil surface, and occur on the same landscape positions.
Sharvana, and Simona soils have an ochric epipedon, and occur on slightly lower landscape positions.
Sharvana soils: have an argillic horizon, and occur in similar landscape positions.

DRAINAGE AND PERMEABILITY: Well drained. Moderate permeability. Runoff is low on slopes less than 1 percent and medium on 1 to 3 percent slopes.

USE AND VEGETATION: These soils are used nearly exclusively for rangeland.
In the southern part of the distribution of this series, the climax vegetation includes sideoats grama, little bluestem, buffalograss, hairy grama, slim tridens, purple and wright threeawns, bushsunflower, gray goldaster, daleas, gayfeather, plains blackfoot, sundrops, catclaw, ephedra, hackberry, and javelinabrush. In the northern part of the distribution, the climax vegetation consists of blue grama, lack grama, sideoats grama, little bluestem, sand dropped, New Mexico feathergrass, galleta, catclaw, feather dahlia, dotted gayfeather, plains blackfoot, slim tridens, hairy grama, rock daisy, catclaw, and broom snakeweed.

DISTRIBUTION AND EXTENT: Southeastern New Mexico and Southwestern High Plains of Texas (MLRA-77). The series is extensive.

MLRA OFFICE RESPONSIBLE: Temple, Texas.

SERIES ESTABLISHED: Lea County, New Mexico, (Reconnaissance Survey of Eastern
New Mexico), 1936.

REMARKS: Classification change from Petrocalcic Calciustolls to Ustic Petrocalcids based on an evaluation of the geographic extent of these soils, and the climate in which they occur.

Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon: 0 to 8 inches. (A1, A2 horizons) This horizon qualifies for a mollic epipedon except for dryness.
Petrocalcic horizon: 8 to 36 inches. (Bkm horizon)

Soil interpretations record: NM0337

Taxonomic version: Keys to Soil Taxonomy, Eight Edition, 1998.

National Cooperative Soil Survey
U.S.A.