LOCATION PAALOA HIEstablished Series
TAXONOMIC CLASS: Very-fine, sesquic, isothermic Humic Rhodic Kandiudox
TYPICAL PEDON: Paaloa silty clay - unirrigated sugarcane. (Colors are for moist soil unless otherwise noted. All textures are "apparent field textures.")
Ap--0 to 17 inches; about 50 percent dark brown (7.5YR 3/2) and 50 percent dark reddish brown (2.5YR 3/3) silty clay, dark brown (7.5YR 4/4) and dark reddish brown (2.5YR 3/4) dry; strong fine and very fine subangular blocky structure; hard, firm, sticky and plastic; many roots; few fine and very fine tubular and interstitial pores; strongly acid (pH 5.4); abrupt smooth boundary. (15 to 17 inches thick)
B21t--17 to 25 inches; dark reddish brown (2.5YR 3/4) silty clay, dark red (2.5YR 3/6) dry; moderate fine and very fine subangular blocky structure; hard, friable, sticky and plastic; few roots; root mat caps this horizon; common fine tubular pores; dusky red (10R 3/4) moist clay films in pores, moderately thick nearly continuous clay films on peds; strongly acid (pH 5.1); clear wavy boundary. (6 to 9 inches thick)
B22t--25 to 36 inches; dark reddish brown (2.5YR 3/4) moist and dry silty clay; moderate fine and very fine subangular blocky structure; hard, friable, sticky and plastic; few very fine roots; many fine and medium tubular pores; thin nearly continuous dark red (10R 3/6) moist clay films in pores, thin patchy films on peds; 30 to 50 percent dark reddish brown (5YR 3/3) moist saprolite pebbles coated with clay films; very strongly acid (pH 4.7); clear wavy boundary. (10 to 12 inches thick)
B23t--36 to 45 inches; dark reddish brown (2.5YR 3/4) clay, dark red (2.5YR 3/6) dry; moderate medium fine and very fine subangular blocky structure; hard, firm, sticky and very plastic; few very fine roots; few very fine and fine tubular pores; thin continuous dark red (10R 3/6) moist clay films in pores, thin patchy films on peds; very strongly acid (pH 4.8); clear smooth boundary. (9 to 11 inches thick)
B24t--45 to 60 inches; dark reddish brown (2.5YR 3/4) silty clay, dark red (2.5YR 3/6) dry; moderate fine and very fine subangular blocky structure; hard, friable, sticky and very plastic; few fine roots; common tubular pores; thin continuous dark red (10R 3/6) moist clay films in pores, thin patchy clay films on peds; very strongly acid (pH 4.7).
TYPE LOCATION: Honolulu County, Hawaii; Hauula Quadrangle - 21 degrees 36' 02" north latitude and 158 degrees 01' 30" west longitude; Waialua Sugar Company, from Kawailoa Camp, 4.15 miles toward the mountains on Kawailoa Road to the intersection of Pupukea Road that turns south; thence on Kawailoa Road 0.3 mile to a plantation road, north 0.3 mile on plantation road, 50 feet west of road.
RANGE IN CHARACTERISTICS: The amount of saprolite gravel ranges from 5 to 50 percent in the B horizon.
Where the soil is uncultivated, the A horizon has hue of 7.5YR or 10YR and chroma of 2 moist and dry. The Ap horizon has chroma of 2 or 3 moist and 2 through 4 dry. A horizon is silty clay or clay. One- to four-inch chunks of soil high in titanium oxide are common in the A horizon.
The B horizon has hue of 2.5YR or 10R, value of 3 or 4, and chroma of 3 through 6 dry or moist. It is silty clay or clay.
COMPETING SERIES: These are the Honolua, Kokee, Leilehua, Makawao and Olelo series. Honolua soils have 5YR or 7.5YR hue in the argillic horizon. Kokee soils have 7.5YR or 10YR hue in the argillic horizon. Leilehua soils are extremely acid throughout the solum and have thin patchy clay films throughout the argillic horizon. Makawao soils are slightly acid and weakly smeary in the argillic horizon and have thin clay films in the argillic horizon. Olelo soils have strong structure and continuous moderately thick clay films in the lower part of the argillic horizon.
GEOGRAPHIC SETTING: Paaloa soils are on uplands at elevations ranging from just below the steeply sloping, deeply dissected areas covered by rain forest. Slopes range from 2 to 12 percent and are nearly everywhere convex except for the toeslopes which are concave. These soils formed in alluvium and residuum weathered from basic igneous rocks. Mean annual rainfall is 70 to 90 inches. Average January temperature is 67 degrees F.; average July temperature is 73 degrees F.; and mean annual temperature is about 70 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kapaa, Manana and Wahiawa soils and the competing Leilehua soils. Kapaa soils have an oxic horizon that has a high concentration of gibbsite. Manana soils lack clay films in the upper part of the B horizon and have a thin panlike layer at depths of 15 to 50 inches. Wahiawa soils lack an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderately rapid permeability.
USE AND VEGETATION: Dryland sugarcane and pasture. Natural vegetation is ohia (Metrosideros collina), koa (Acacia confusa), guava (Psidium guajava), fern, and californiagrass (Panicum purpurascens).
DISTRIBUTION AND EXTENT: Island of Oahu, Hawaii; below the rain forest of the Koolau Range between Wahiawa and Waimea Bay. The soils are of small extent consisting of about 3,300 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Soil Survey of the Territory of Hawaii, 1949.
OSED scanned by SSQA. Last revised by state on 5/78.