LOCATION UWALA HI

Established Series
Rev. SN/RCH/MRK/ET
09/2019

UWALA SERIES

The Uwala series consists of deep, well drained soils that formed in residuum weathered from basalt. Uwala soils are on low elevation plateaus and are gently to moderately sloping. Mean annual rainfall is about 381 to 635 millimeters (15 to 25 inches) and mean annual temperature is about 21 degrees C. (70 degrees F.)

TAXONOMIC CLASS: Very-fine, kaolinitic, isohyperthermic Typic Haplotorrox

TYPICAL PEDON: Uwala silty clay loam - cultivated. (Colors are for moist soil unless otherwise noted. All textures are "apparent field textures.")

Ap1--0 to 13 centimeters (0 to 5 inches); dark reddish brown (5YR 3/3) silty clay loam, reddish brown (5YR 4/3) dry; weak medium and fine subangular blocky structure parting to weak fine granular; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; few fine interstitial pores; common fine black concretions; strong effervescence with hydrogen peroxide; very strongly acid; clear wavy boundary. (8 to 15 centimeters thick)

Ap2--13 to 46 centimeters (5 to 18 inches); dark reddish brown (5YR 3/3) silty clay loam, reddish brown (5YR 4/3) dry; weak fine and medium subangular blocky structure parting to moderate fine granular; slightly hard, friable, slightly sticky and moderately plastic; many very fine and fine roots; common very fine tubular and interstitial pores; few fine black concretions; common fragments of burned organic matter; moderate effervescence with hydrogen peroxide; very strongly acid; abrupt smooth boundary. (31 to 36 centimeters thick)

Bto1--46 to 66 centimeters (18 to 26 inches); dark reddish brown (5YR 3/4) silty clay loam, yellowish red (5YR 3/6) dry; moderate fine subangular blocky structure; slightly hard, firm, slightly sticky and moderately plastic; few fine roots; many fine tubular pores; moderately thick patchy coatings on all faces of peds; common fine black concretions; strong effervescence with hydrogen peroxide; medium acid; clear smooth boundary. (18 to 23 centimeters thick)

Bto2--66 to 81 centimeters (26 to 32 inches); dark reddish brown (5YR 3/4) moist and dry silty clay loam; strong fine blocky structure; hard, firm, moderately sticky and moderately plastic; common fine tubular pores; moderately thick patchy coatings on faces of peds; few black concretions; few very firm earthy lumps; very weak effervescence with hydrogen peroxide; medium acid; clear smooth boundary. (13 to 18 centimeters thick)

Bto3--81 to 112 centimeters (32 to 44 inches); dark reddish brown (5YR 3/4) moist and dry silty clay loam; strong fine and very fine subangular blocky and angular blocky structure; hard, firm, moderately sticky and moderately plastic; many fine and very fine tubular pores; nearly continuous coatings on surfaces of peds, many of which look like pressure surfaces; common fine earthy lumps; few fine black concretions; many very fine weathered rock particles; effervescence with hydrogen peroxide limited to the black concretions; medium acid; gradual wavy boundary.(25 to 38 centimeters thick)

BC--112 to 145 centimeters (44 to 57 inches); dark reddish brown (5YR 3/3) silty clay loam, dark reddish brown (5YR 3/4) dry; weak very fine angular and subangular blocky structure; hard, firm, slightly sticky and moderately plastic; many fine and very fine and medium tubular pores; many very fine weathered rock particles; no effervescence with hydrogen peroxide; medium acid; clear smooth boundary. (28 to 36 centimeters thick)

C--145 to 152 centimeters (57 to 60 inches); very dark grayish brown (10YR 3/2) light silty clay loam, dark brown (10YR 3/3) dry; weak very fine subangular blocky structure; hard, friable, slightly sticky and moderately plastic; few fine tubular pores; common fine earthy lumps; numerous fragments of saprolite that increase with increasing depth.

TYPE LOCATION: Island of Lanai, Maui County, Hawaii; 20 degrees 58 minutes 17.31 seconds north latitude and 156 degrees 58 minutes 10.24 seconds west longitude (WGS84 datum); field 5517-18, block 19G, Dole Corporation; approximately 1 1/2 miles southeast of Lanai airport.

RANGE IN CHARACTERISTICS: Depth to weathered basalt ranges from 3 to 7 feet, 4 feet being most common. Some areas contain weathered pebbles in the A horizon. Mean annual soil temperature is about 22 degrees C. (72 degrees F.) The soil is dry in some horizons for more than 90 cumulative days in most years.

The A and B horizon have hue of 5YR or 7.5YR.

The B horizon has moderate or strong structure.

COMPETING SERIES: These are the Hoolehua and Waipahu series. Hoolehua soils have strong effervescence with hydrogen peroxide in the B horizon. Waipahu soils have deeply grooved slickensides.

GEOGRAPHIC SETTING: Uwala soils are on gently to moderately sloping plateaus at elevations of 152 to 457 meters (500 to 1,500 feet). The soils formed in basalt residuum with possible influence of volcanic ash and cinders. Annual rainfall is 381 to 635 millimeters (15 to 25 inches), most of which falls from November to April. The average January air temperature is about 20 degrees C. (68 degrees F.); average July air temperature is about 23 degrees C. (73 degrees F.) Mean annual air temperature is about 21 degrees C. (70 degrees F.)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Lahaina, Molokai and Waikapu soils. Lahaina and Molokai soils have 2.5YR or redder hue in the B horizon. Waikapu soils have slickensides in the B horizon.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium runoff; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Used for pineapple, pasture and wildlife habitat. Present vegetation is kiawe (Prosopis chilensis), feather fingergrass (Chloris virgata), lantana (Lantana camara) and cactus (Opuntia megacantha).

DISTRIBUTION AND EXTENT: Central plateau on island of Lanai, Hawaii. The series is inextensive with a total of about 4,000 acres.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Maui County, Hawaii, 1971.

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

Umbric epipedon - 0 to 46 centimeters (Ap horizon)
Kandic horizon - 46 to 145 centimeters (Bto and BC horizon)

OSED scanned by SSQA. Last revised by state on 8/2001.

National Cooperative Soil Survey
U.S.A.