LOCATION SADDLEBROOK             AZ

Established Series
Rev. CAP
05/2011

SADDLEBROOK SERIES

The Saddlebrook series consists of very shallow and shallow, well drained soils that formed in mixed fan alluvium. Saddlebrook soils are on fan terraces. Slopes range from 1 to 60 percent. The mean annual precipitation is about 14 inches and the mean annual air temperature is about 64 degrees F.

TAXONOMIC CLASS: Clayey, mixed, superactive, thermic, shallow Ustalfic Petrocalcids

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

A--0 to 2 inch (0 to 5 cm); strong brown (7.5YR 5/6) loam, dark brown (7.5YR 3/4) moist; 20 percent clay; weak thin platy parting to weak very fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine roots; many very fine irregular pores; 10 percent gravel; noneffervescent; slightly acid (pH 6.2); abrupt smooth boundary. (1 to 3 inches thick)

Bt--2 to 9 inches (5 to 23 cm); dark red (2.5YR 3/6) clay, dark reddish brown (2.5YR 3/4) moist; 50 percent clay; strong fine and medium angular blocky structure; hard, firm, very sticky and very plastic; many very fine roots; many very fine tubular pores; common continuous distinct clay films on faces of peds and rock fragments; 3 percent gravel; noneffervescent; slightly acid (pH 6.4); clear smooth boundary. (3 to 9 inches thick)

Btk--9 to 16 inches (23 to 41 cm); dark reddish brown (2.5YR 3/4) clay, dark reddish brown (2.5YR 3/4) moist; 72 percent clay; strong fine and medium angular blocky structure; hard, firm, very sticky and very plastic; few very fine roots; many very fine tubular pores; common continuous distinct clay films on faces of peds and rock fragments; few continuous distinct carbonate coats on rock fragments; few carbonate filaments; 5 percent gravel; strongly effervescent, 8 percent calcium carbonate equivalent; neutral (pH 6.8); abrupt wavy boundary. (3 to 8 inches thick)

Bkkm--16 to 60 inches (41 to 152 cm); calcium carbonate cemented material, indurated; petrocalcic.

TYPE LOCATION: Pinal County, Arizona; located at a latitude of 32 degrees, 33 minutes, 38 seconds north and longitude of 110 degrees, 52 minutes, 18 seconds west; USGS Quadrangle Oracle Junction; about 200 feet south and 250 feet east of the northwest corner of Section 23, T. 10 S., R. 14 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: 62 to 69 degrees F.

Rock fragments: 0 to 20 percent gravel and/or cobble above the hardpan

Reaction: slightly acid to moderatetly alkaline (pH 6.1 to 8.4)

Calcium carbonate equivalent: 0 to 15 percent above the hardpan

Depth to petrocalcic horizon: 8 to 20 inches

Average percent clay in the control section: 35 to 65 percent

A Horizon
Hue: 5YR, 7.5YR
Value: 3 to 5 dry, 2.5 to 4 moist
Chroma: 2 to 6 dry, 1 to 4 moist
Texture: loam, sandy loam, clay loam

Bt & Btk Horizons
Hue: 5YR, 2.5YR
Value: 2.5 to 5 dry, 3 or 4 moist
Chroma: 2 to 6 dry, 1 to 4 moist
Texture: clay, clay loam, sandy clay loam

Bkkm Horizon
Cemented: calcium carbonate
Hardness: indurated
Thickness: 1 to 6 feet; continuous

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Saddlebrook soils are on fan terraces at elevations of 3,200 to 3,900 feet. Slopes range from 1 to 60 percent. These soils formed in mixed fan alluvium. The mean annual precipitation is 12 to 16 inches and occurs as thunderstorms during July to September and as gentle rains during December to February. The mean annual air temperature is 60 to 67 degrees F. The frost-free period is 180 to 230 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Selevin, Stronghold, Tombstone, and White House soils. These soils are all very deep and do not have hardpans.

DRAINAGE AND PERMEABILITY: Well drained; rapid runoff; slow permeability above the hardpan.

USE AND VEGETATION: Used for livestock grazing and wildlife habitat. Vegetation includes catclaw acacia, javelina bush, Pima pappusgrass, pricklypear, Rothrock's grama, sideoats grama, tobosa, threeawn, mesquite, condalia, false mesquite, ocotello, and ratany.

DISTRIBUTION AND EXTENT: Southern Arizona. Saddlebrook soils are of limited extent. MLRA is 41.

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

SERIES ESTABLISHED: Pinal County, Arizona. Soil survey of Eastern Pinal and Southern Gila Counties, Arizona 2009.

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

Ochric epipedon - the zone from 0 to 2 inches (A horizon)

Argillic horizon - the zone from 2 to 16 inches (Bt, Btk horizons)

Petrocalcic horizon - the zone from 16 to 60 inches (Bkm horizon)

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

Revised for the correlation of Graham County, AZ, Southwestern Part; March, 2011, WWJ

---

National Cooperative Soil Survey
U.S.A.