LOCATION BORDERLINE AZ

Established Series
Rev. WAS/PDC/CEM
10/2013

BORDERLINE SERIES

The Borderline series consists of very deep, well drained soils that formed in alluvium from mixed sources. Borderline soils are on fan piedmonts. Slopes range from 2 to 15 percent. The mean annual precipitation is about 11 inches (279 mm) and the mean annual air temperature is about 64 degrees F (17.8 degrees C).

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, thermic Typic Calcigypsids

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

A--0 to 2 inches; (0 to 5 cm); light brown (7.5YR 6/4) fine sandy loam, brown (7.5YR 4/4) moist; moderate thick platy structure; soft, very friable, nonsticky and slightly plastic; few fine roots; many fine vesicular pores; violently effervescent, 3 percent calcium carbonate equivalent; moderately alkaline (pH 8.0); abrupt smooth boundary. (1 to 3 inches thick)

Bky1--2 to 18 inches; (5 to 46 cm); light brown (7.5YR 6/4) loam, brown (7.5YR 5/4) moist; weak fine subangular blocky structure; soft, very friable, moderately sticky and moderately plastic; many very fine and fine and few medium roots; common fine irregular and tubular pores; few fine distinct calcium carbonate and gypsum filaments; many fine soft calcium carbonate and gypsum masses; many distinct calcium carbonate and gypsum coatings on ped faces and rock fragments; many very fine gypsum crystals throughout; 10 percent gravel; violently effervescent, 28 percent calcium carbonate equivalent and 10 percent gypsum; moderately alkaline (pH 8.0); abrupt wavy boundary.

Bky2--18 to 41 inches; (46 to 104 cm); 50 percent strong brown (7.5YR 5/6) and 50 percent light brown (7.5YR 6/4) sandy loam, brown (7.5YR 5/4) moist; moderate fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; many fine and medium tubular pores; common fine calcium carbonate and gypsum filaments; many distinct calcium carbonate and gypsum coatings on ped faces and rock fragments; many very fine and fine gypsum crystals throughout and on ped faces; common distinct organic coatings on ped faces; 10 percent gravel; violently effervescent, 12 percent calcium carbonate equivalent and 10 percent gypsum; moderately alkaline (pH 8.0); clear smooth boundary. (Combined thickness of the Bky horizons is 30 to 45 inches)

Bk1--41 to 50 inches; (104 to 127 cm); brown (7.5YR 5/3) sandy loam, brown (7.5YR 5/4) moist; massive; slightly hard, very friable, nonsticky and nonplastic; common very fine and fine roots; many fine and medium irregular and tubular pores; few distinct calcium carbonate coatings on rock fragments; few distinct organic coatings in seams; 5 percent gravel; violently effervescent, 16 percent calcium carbonate equivalent; moderately alkaline (pH 8.0); abrupt wavy boundary.

Bk2--50 to 60 inches; (127 to 152 cm); brown (7.5YR 5/3) gravelly sandy loam, brown (7.5YR 5/4) moist; massive; slightly hard, very friable, nonsticky and nonplastic; common very fine and fine roots; common fine irregular pores; few distinct calcium carbonate coatings on rock fragments; few distinct organic coatings on seams; 25 percent gravel; violently effervescent, 11 percent calcium carbonate equivalent; moderately alkaline (pH 8.0). (Combined thickness of the Bk horizons is 15 to 25 inches)

TYPE LOCATION: Cochise County, Arizona; located at a latitude of 31 degrees, 48 minutes, 54 seconds North and longitude of 110 degrees, 15 minutes, 22 seconds West; about 2,650 feet east and 1,200 feet south of the northwest corner of Section 1, T. 19 S., R. 20 E.

RANGE IN CHARACTERISTICS:
Soil moisture - Intermittently moist in some part of the soil moisture control section during December - February and for more than 20 days cumulative during July - September. Driest during May and June. Typic aridic soil moisture regime.

Soil Temperature: 62 to 70 degrees F (16.7 degree C).

Surface gravel: 30 to 80 percent

Reaction: slightly to moderately alkaline

Clay content: less than 18 percent in control section

Depth to calcic horizon: 2 to 20 inches (5 to 51 cm)

Depth to gypsic horizon: 2 to 20 inches (5 to 51 cm)

A horizon
Hue: 7.5YR, 10YR
Value: 5 or 6 dry, 3 to 5 moist
Chroma: 4 or 6 dry, 3 or 4 moist
Texture: fine sandy loam, sandy loam
Calcium carbonate equivalent: 0 to 5 percent

Bky horizons
Hue: 7.5YR, 10YR
Value: 5 to 7 dry, 3 to 6 moist
Chroma: 4 to 6, dry or moist
Texture: loam, sandy loam, fine sandy loam
Rock fragments: 0 to 15 percent gravel
Calcium carbonate equivalent: 10 to 30 percent
Gypsum content: 5 to 10 percent

Bk horizons
Hue: 7.5YR, 10YR
Value: 5 or 6 dry, 3 to 5 moist
Chroma: 3 to 6, dry or moist
Texture: sandy loam, loam, fine sandy loam, silt loam
Rock fragments: 5 to 30 percent gravel
Calcium carbonate equivalent: 10 to 20 percent
Gypsum content: 0 to 2 percent

COMPETING SERIES: These are the Alamogordo (NM), Hobcan (AZ), Monahans (TX), Monzingo (AZ) and Ugyp (AZ) series. Alamogordo soils have more than 25 percent gypsum. Hobcan soils are moist in the soil moisture control section for less than 20 days cumulative during July - September and occur in the Mohave Desert. Monahans soils have depth to gypsic horizon that ranges from 16 to 36 inches. Monzingo soils contain Cd horizons. Ugyp soils have stratified textures in the Bky horizons and are subject to flooding and occur on alluvial fans.

GEOGRAPHIC SETTING: Borderline soils are on fan piedmonts at elevations of 3,800 to feet 4,100 (1,158 to 1,250 meters). Slopes range from 2 to 15 percent. These soils formed in alluvium from mixed sources. The mean annual precipitation is 10 to 12 inches (254 to 305 cm) and occurs as thunderstorms during July to September and as gentle rains during December to February. The mean annual air temperature is 60 to 68 degrees F (16 to 20 degrees C). The frost-free period is 190 to 260 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ugyp and Contention soils. Contention soils are fine textured. Ugyp are on alluvial fans and stream terraces.

DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately rapid permeability.

USE AND VEGETATION: Used for livestock grazing and wildlife habitat. Vegetation includes tarbush, creosotebush, snakeweed, bush muhly and desert zinnia.

DISTRIBUTION AND EXTENT: Southern Arizona. Borderline soils are of moderate extent. MLRA is 41.

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

SERIES ESTABLISHED: Cochise County, Arizona; Soil survey of Cochise County, Arizona, Douglas - Tombstone Part; 1996.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 2 inches ( 0 to 5 cm)(A horizon)
Gypsic horizon - The zone from 2 to 41 inches (5 to 104 cm)(Bky1, Bky2 horizons)
Calcic horizon - The zone from 2 to 60 inches (5 to 152 cm)(Bky1,)

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

Revised for the correlation the SDJR - MLRA 41 - Borderline fine sandy loam, 2 to 15 percent slopes project, September 2013, LJG2

National Cooperative Soil Survey
U.S.A.