LOCATION KOLOA HI

Established Series
Rev. SN-CWS-MRK
09/2020

KOLOA SERIES

The Koloa series consists of moderately deep, well drained soils that formed in residuum weathered from volcanic ash and basic igneous rock. Koloa soils are on low elevation, mountain hillslopes, ridges, and volcanic vents; and, have slopes of 3 to 25 percent. Mean annual rainfall is about 1,270 millimeters (50 inches), and mean annual air temperature is about 23 degrees C. (74 degrees F.)

TAXONOMIC CLASS: Fine, mixed, active, isohyperthermic Andic Argiustolls

TYPICAL PEDON: Koloa stony silty clay - pasture. (Colors are for moist soil unless otherwise noted. All textures are "apparent field textures."

Ap--0 to 18 centimeters (0 to 7 inches); dark reddish brown (5YR 3/3) stony silty clay, weak red (2.5YR 4/2) dry; strong fine and very fine subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; many fine roots; common fine pores; 15 percent stones; violent effervescence with hydrogen peroxide; slightly acid (pH 6.1); clear smooth boundary. (15 to 25 centimeters thick)

Bt1--18 to 33 centimeters (7 to 13 inches); dark reddish brown (2.5YR 3/3) stony silty clay, rubbed color dark reddish brown (2.5YR 3/4); dark reddish brown (5YR 3/3) dry; weak fine subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; common fine roots; common fine pores; 15 percent stones; strong effervescence with hydrogen peroxide; few, patchy, distinct clay films on peds; few highly weathered pebbles; neutral (pH 6.7); gradual smooth boundary. (15 to 31 centimeters thick)

Bt2--33 to 51 centimeters (13 to 20 inches); dark reddish brown (2.5YR 3/4) stony silty clay, dark red (2.5YR 3/6) dry; weak fine and very fine subangular blocky structure with pockets of strong very fine subangular blocky structure; very hard, firm, very sticky and moderately plastic; common very fine roots; many fine pores; 25 percent stones; slight effervescence with hydrogen peroxide; common, continuous, distinct clay films on peds; many highly weathered pebbles with black coatings inside; neutral (pH 6.8); abrupt irregular boundary. (18 to 46 centimeters thick)

R--51 centimeters (20 inches); hard pahoehoe bedrock with a thin weathered crust; vesicles in rock have black coatings that very slightly effervesce with hydrogen peroxide.

TYPE LOCATION: Island of Kauai, Kauai County, Hawaii. Koloa Quadrangle - 21 degrees 53 minutes 06 seconds north latitude and 159 degrees 26 minutes 15 seconds west longitude (WGS84).

RANGE IN CHARACTERISTICS: Mean annual soil temperature is about 23 degrees C. (74 degrees F.) Depth to bedrock ranges from 51 to 102 centimeters (20 to 40 inches.) Some pedons may be deeper than 102 centimeters (40 inches). Fine black concretions range from none to many in the A and B horizons. The soil is slightly acid to neutral throughout the soil profile.

The A horizon has hue of 2.5YR to 5YR, value of 2 to 4 and chroma of 2 or 3. It may be violently to strongly effervescent with hydrogen peroxide.

The B horizon has hue of 10R through 5YR, and chroma of 3 through 6. It may be strongly to very slightly effervescent with hydrogen peroxide.
Clay films may not be present in all pedons.

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: The Koloa soils are on low elevation, mountain hillslopes, ridges and old volcanic vents. Slopes range from 3 to 25 percent but are dominantly 3 to 8 percent. Elevation ranges from near sea level to 243 meters (800 feet). The soils formed in residuum weathered from volcanic ash and basic igneous rock. Annual rainfall is 1,016 to 1,524 millimeters (40 to 60 inches). Average January air temperature is 22 degrees C. (7l degrees F.); average July air temperature is 26 degrees C. (78 degrees F.) Mean annual air temperature is about 23 degrees C. (74 degrees F.)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Mamala and Waikomo soils. Mamala soils are mildly alkaline and are underlain by consolidated calcareous sand or coral at depths less than 51 centimeters (20 inches.) Waikomo soils have an A horizon with colors as yellow or yellower than 7.5YR, are less than 51 centimeters (20 inches) deep over bedrock.

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

USE AND VEGETATION: These soils are used for pasture, orchard crops, woodland and wildlife habitat. In the past, most of these soils were used to produce irrigated sugarcane. Natural vegetation is mainly koa haole (Leucaena glauca).

DISTRIBUTION AND EXTENT: Island of Kauai, Kauai County, Hawaii. This series is approximately 2,500 acres in extent.

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

SERIES ESTABLISHED: Island of Kauai, Kauai County, Hawaii, 1971.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon- from the surface to 18 centimeters (Ap)
Argillic horizon- from 18 to 51 centimeters (Bt1, Bt2)
Lithic contact- The boundary at 51 centimeters (R)

Edit Log: 9/19 MK. Horizon designations, landscape and landform, range in characteristics, use and management, diagnostic horizons, and other minor changes made.
Last revised by state 8/2000.

ADDITIONAL DATA: NSSL Koloa sample S89HI007002.

National Cooperative Soil Survey
U.S.A.