LOCATION PUU OPAE HIEstablished Series
TAXONOMIC CLASS: Very-fine, parasesquic, isothermic Ustic Palehumults
TYPICAL PEDON: Puu Opae silty clay loam - pasture. (Colors are for moist soil unless otherwise noted. All textures are "apparent field textures.")
A11--0 to 7 inches; dusky red (2.5YR 3/2) silty clay loam, weak red (2.5YR 4/2) dry; moderate fine and very fine subangular blocky structure; slightly hard, friable, sticky and plastic; many roots; many fine pores; strong effervescence with hydrogen peroxide; strongly acid (pH 5.3); clear smooth boundary. (6 to 8 inches thick)
A12--7 to 10 inches; dusky red (2.5YR 3/2) loam, dark reddish brown (2.5YR 3/3) dry; weak fine subangular blocky structure; weakly coherent, very friable, slightly sticky and slightly plastic; many roots; many fine pores; strong effervescence with hydrogen peroxide; medium acid (pH 5.6); clear smooth boundary. (3 to 5 inches thick)
B1--10 to 14 inches; dark reddish brown (2.5YR 3/3) light silty clay, reddish brown (2.5YR 4/3) dry; moderate fine and very fine subangular blocky structure; hard, friable, sticky and plastic; many roots; many fine pores; very few thin clay films on faces of peds; moderate effervescence with hydrogen peroxide; strongly acid (pH 5.5); clear smooth boundary. (3 to 5 inches thick)
B21t--14 to 29 inches; reddish brown (2.5YR 4/4) silty clay, same color dry; weak fine and very fine subangular blocky structure; hard, firm, very sticky and plastic; common roots; common fine and very fine pores; thin patchy clay films on faces of peds; no effervescence with hydrogen peroxide; strongly acid (pH 5.3); gradual smooth boundary. (12 to 18 inches thick)
B22t--29 to 61 inches; reddish brown (2.5YR 4/3) silty clay, same color dry; moderate fine and very fine angular blocky structure; hard, firm, very sticky and plastic; few roots; few fine and very fine pores; nearly continuous moderately thick clay films on faces of peds; sugar-like coatings of higher chroma in pores; strongly acid (pH 5.1); gradual smooth boundary. (26 to 38 inches thick)
B23t--61 to 66 inches; dark reddish brown (2.5YR 3/4) silty clay, weak red (2.5YR 4/2) dry; strong fine and very fine angular and subangular blocky structure; hard, firm, sticky and plastic; few roots; few fine pores; glazed appearance; continuous moderately thick clay films on faces of peds; sugar-like coatings of higher chroma in pores; very strongly acid (pH 4.8).
TYPE LOCATION: Island of Kauai, Kauai County, Hawaii; Kekaha Quadrangle - 22 degrees 02' 16.6" north latitude and 159 degrees 41' 52" west longitude.
RANGE IN CHARACTERISTICS: Depth to weathered rock ranges from about 4 feet to more than 6 feet. Mean annual soil temperature is about 70 degrees F. Moist hue of the A and B horizons ranges from 2.5YR through 10R. Value in the B horizon is 3 or 4, and chroma ranges from 2 through 6.
COMPETING SERIES: These are the Halawa, Ioleau, Kalae, Kanepuu, and Kemoo series. Halawa soils have 5YR or 7.5YR hue in the A horizon and strong structure and thin clay films throughout the argillic horizon. Ioleau soils have isohyperthermic temperature and a B horizon that is very compact in place. Kalae soils have an ochric epipedon, and strong structure and thin clay films in the argillic horizon. Kanepuu soils are neutral or slightly acid throughout the solum and have 5YR hue in the A horizon and 5YR or 7.5YR hue in the B horizon. Kemoo soils are slightly acid or neutral throughout the solum, have a base saturation of more than 50 percent in the B horizon, and strong structure throughout the argillic horizon.
GEOGRAPHIC SETTING: Puu Opae soils are on uplands of western and northern Kauai. Slopes range from 8 to 40 percent. Elevation ranges from 500 to 2,500 feet. The soils formed in residuum from basic igneous rock. The annual rainfall ranges from 30 to 50 inches. Average January temperature is about 66 degrees F.; average July temperature is about 75 degrees F.; and mean annual temperature is about 70 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Mahana, Niu, and Oli soils. Mahana and Oli have textures of silty clay loam or coarser in the control section. Niu soils are neutral and effervesce with hydrogen peroxide in the control section.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff depending on slope; moderately rapid permeability.
USE AND VEGETATION: Mainly used for pasture, but a small area is used for irrigated sugarcane. Natural vegetation is molassesgrass (Melinis minutiflora), silver oak (Grevillea robusta), passionflower (Passiflora foetida), puakeawe (Styphelia tameiameiae), yellow foxtail (Setaria geniculata), lantana (Lantana camara), uluhe (Gleichenia linearis), ti (Cordyline terminalis), and aalii (Dodonaea eriocarpa).
DISTRIBUTION AND EXTENT: Western and northern parts of the island of Kauai, Hawaii. The series is of small extent comprising about 3,100 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Kauai County, Island of Kauai, Hawaii, 1971.
OSED scanned by SSQA. Last revised by state on 5/78.