LOCATION KAHANA HIEstablished Series
TAXONOMIC CLASS: Very-fine, kaolinitic, isohyperthermic Oxic Dystrustepts
TYPICAL PEDON: Kahana silty clay - sugarcane. (Colors are for moist soil unless otherwise noted. All textures are "apparent field textures.")
Ap1--0 to 7 inches; dark reddish brown (2.5YR 2/4) silty clay, dark reddish brown (2.5YR 3/4) dry; moderate fine and very fine subangular blocky structure; hard, friable, very sticky and very plastic; many fine roots; many fine and very fine pores; many very fine black concretions; violent effervescence with hydrogen peroxide; strongly acid (pH 5.2); clear wavy boundary. (6 to 9 inches thick)
Ap2--7 to 14 inches; dark reddish brown (2.5Y 2/4) silty clay, dark reddish brown (2.5YR 3/4) dry; moderate medium and fine subangular blocky structure; hard, firm, very sticky and very plastic; many fine and very fine pores; many fine and very fine black concretions; violent effervescence with hydrogen peroxide; very strongly acid (pH 5.0); abrupt wavy boundary. (6 to 9 inches thick)
Bo1--14 to 22 inches; dark reddish brown (2.5YR 3/4) silty clay, dark reddish brown (2.5YR 3/4) dry; moderate medium and fine subangular blocky structure; hard, firm, very sticky and very plastic; many fine and very fine pores; many fine and very fine black concretions; violent effervescence with hydrogen peroxide; very strongly acid (pH 5.0); abrupt wavy boundary. (6 to 9 inches thick)
Bo2--22 to 34 inches; dark reddish brown (2.5YR 3/4) silty clay, dark red (2.5YR 3/6) dry; strong very fine subangular blocky structure; hard, firm, sticky and very plastic; few fine roots; many fine and very fine tubular pores; continuous pressure faces on peds that resemble slickensides; common sand-size aggregates that are resistant to crushing; continuous pressure faces on peds; common fine and very fine black concretions; strong effervescence with hydrogen peroxide; neutral (pH 6.6); clear wavy boundary. (8 to 15 inches thick)
Bo3--34 to 47 inches; dark reddish brown (2.5YR 3/4) silty clay, dark red (2.5YR 3/6) dry; strong very fine subangular blocky structure; hard, firm, sticky and very plastic; few fine roots; many fine and very fine tubular pores; continuous pressure faces on peds that resemble slickensides; common sand-size aggregates that are resistant to crushing; many fine and very fine black concretions; common black coatings on peds; slight effervescence with hydrogen peroxide in matrix, violent effervescence on black coatings; neutral (pH 6.7); clear wavy boundary. (10 to 18 inches thick)
Bo4--47 to 61 inches; dark reddish brown (2.5YR 3/4) silty clay, dark red (2.5YR 3/4) silty clay, dark red (2.5YR 3/6) dry; strong very fine and subangular blocky structure; slightly hard, friable, sticky and very plastic; many coarse, medium and fine tubular pores; continuous pressure faces on peds; common highly weathered pebbles that can be broken with the fingers; neutral (pH 6.8).
TYPE LOCATION: Island of Maui, Maui County, Hawaii; Honolua Quadrangle - 20 degrees 57 minutes 44 seconds north latitude and 156 degrees 39 minutes 00 seconds west longitude; 0.25 mile northwest of Mahinahina Camp in sugarcane field and 50 feet west of concrete canal on Pioneer Mill Company land.
RANGE IN CHARACTERISTICS: Thickness of the solum is more than 40 inches.
The A horizon has value of 2 or 3 moist, and chroma of 2 through 4 moist and 3 or 4 dry.
The B horizon has hue of 2.5YR or 10R, and chroma of 3 or 4 moist. It is silty clay or clay.
COMPETING SERIES: These are the Lahaina, Molokai, and Wahiawa series. Lahaina soils have weak to moderate structure in the upper part of the B horizon. Molokai soils have prismatic structure in the upper B horizon and silty clay loam texture in the control section. Wahiawa soils have a mollic epipedon and effervesce with hydrogen peroxide throughout the profile.
Niu series is similar. Niu soils have prismatic structure in the upper part of the B horizon and do not have continuous pressure faces in the B horizon.
GEOGRAPHIC SETTING: The Kahana soils are on uplands and have gradients of 3 to 25 percent. Elevations range from from 100 to 1,200 feet. The soils formed in residuum from basic igneous rock. The average annual precipitation ranges from 30 to 45 inches. The mean annual temperature is about 73 degrees F.; the average January temperature is 70 degrees F.; and the average July temperature is 76 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alaeloa and the competing Lahaina soils. Alaeloa soils have an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; slow or medium runoff depending upon slope; moderately rapid permeability.
USE AND VEGETATION: These soils are used for pineapple and irrigated sugarcane; small acreages are in pasture. Vegetation is guava (Psidium guajava), Japanese tea (Cassia leschenaultiana), klu (Acacia farnesiana), koa haole (Leucaena glauca), lantana (Lantana camara), Natal redtop (Rhyncheytrum), and yellow foxtail (Setaria geniculata).
DISTRIBUTION AND EXTENT: Island of Maui, Maui County, Hawaii. This series is of small extent comprising 2,700 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Soil Survey, Territory of Hawaii, 1949.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon- the zone from the surface to 14 inches (Ap1, Ap2)
Oxic horizon- the zone from 14 to 61 inches (Bo1, Bo2, Bo3, Bo4)