LOCATION KALAPA                  HI

Established Series
Rev. SN/MRK
09/2020

KALAPA SERIES


The Kalapa series consists of very deep, well drained soils that formed in residuum and/or colluvium weathered from basic igneous rock. Kalapa soils are on low mountain hillslopes and have slopes of 8 to 70 percent. The mean annual rainfall is about 2,032 millimeters (80 inches) and the mean annual air temperature is about 22 degrees C. (72 degrees F.)

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

TYPICAL PEDON: Kalapa silty clay - brush and forest. (Colors are for moist soil unless otherwise noted. All textures are "apparent field textures.")

A1--0 to 25 centimeters (0 to 10 inches); dark reddish brown (5YR 3/3) silty clay, moist and dry; moderate fine subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; common fine and very fine roots; many fine and very fine tubular pores; slight effervescence with hydrogen peroxide; very strongly acid (pH 4.8); abrupt wavy boundary. (20 to 31 centimeters thick)

Bt1/A2--25 to 51 centimeters (10 to 20 inches); dark red (2.5YR 3/6) silty clay, reddish brown (2.5YR 4/4) dry; weak fine and very fine subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; few medium, common fine and very fine roots; many fine and very fine tubular pores; few, distinct clay films on surfaces along pores; upper 10 or 13 centimetersis mixed with material from above horizon by earthworms; very strongly acid (pH 4.7); clear wavy boundary. (20 to 28 centimeters thick)

Bt2--51 to 94 centimeters (20 to 37 inches); dark red (2.5YR 3/6) with bands of weak red (2.5YR 4/2) clay, reddish brown (2.5YR 4/4) dry; moderate very fine subangular blocky structure; very hard, firm, very sticky and moderately plastic; few medium, fine and very fine roots; many fine and very fine tubular pores; common, distinct clay films on surfaces along pores; very strongly acid (pH 4.8); clear smooth boundary. (38 to 48 centimeters thick)

Bt3--94 to 112 centimeters (37 to 44 inches); dark red (2.5YR 3/6) clay, red (2.5YR 4/6) dry; sand-size particles of red, white and yellow colors; moderate fine and very fine subangular blocky structure; very hard, firm, very sticky and moderately plastic; few fine and very fine roots; many fine and very fine tubular pores; common, prominent clay films on surfaces along pores; very strongly acid (pH 4.6); clear smooth boundary. (15 to 20 centimeters thick)

Bt4--112 to 127 centimeters (44 to 50 inches); dark reddish brown (5YR 3/4) gravelly clay, dark reddish brown (2.5YR 3/4) dry; moderate fine and very fine subangular blocky structure; very hard, firm, very sticky and moderately plastic; few fine roots; common fine and very fine tubular pores; few, prominent clay films on the surfaces along pores; 20 percent highly weathered gravel; very strongly acid (pH 4.6); clear smooth boundary. (10 to 18 centimeters thick)

C--127 to 152 centimeters (50 to 60 inches); dark brown (7.5YR 3/2), dusky red (10R 3/2), and dark red (10R 3/6) silty clay, weak red (10R 4/2) dry; many fine sand-sized particles of red and white colors; weak fine and very fine subangular blocky structure; very hard, firm, very sticky and very plastic; few fine and very fine tubular pores; very few, prominent clay films on the surfaces along pores, very strongly acid (pH 4.8).

TYPE LOCATION: Island of Kauai, Kauai County, Hawaii; Koloa Quadrangle Elevation 107 meters (350 ft.); 21 degrees 54 minutes 31.54 seconds north latitude and 159 degrees 26 minutes 15.16 seconds west longitude (WGS 84).

RANGE IN CHARACTERISTICS: The mean annual soil temperature is about 22 degrees C. (72 degrees F.) Depth to soft, highly weathered rock ranges from 102(40) to more than 152 centimeters (60 inches). A few stones and boulders occur throughout the solum in some pedons.

The A horizon has hue of 5YR or 7.5YR and chroma of 2 or 3. Effervescence with hydrogen peroxide ranges from none to moderate.

The Bt horizon has hue of 2.5YR or 5YR, value of 3 or 4 and chroma of 3 through 6.

COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: These soils are on low mountain hillslopes on the Island of Kauai. Slopes range from 8 to 70 percent. Elevation ranges from 61 to 366 meters (200 to 1,200 feet). The soils formed in residuum and/or colluvium from basic igneous rocks of the Napali formation of the Waimea Canyon volcanic series. The mean annual rainfall ranges from 1,524 to 2,540 millimeters (60 to 100 inches). The average January air temperature is about 21 degrees C. (69 degrees F.); the average July air temperature is about 23 degrees C. (74 degrees F.); and the mean annual air temperature is about 22 degrees C. (72 degrees F.)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hanamaulu and Hihimanu soils. Hanamaulu soils have strong structure and have silty clay and silty clay loam textures in the control section. Hihimanu soils do not have an argillic horizon and have isothermic soil temperature regime.

DRAINAGE AND SATURATED HYDRAULIC CONDUCVTIVITY: Well drained; medium to very high runoff depending on slope; high saturated hydraulic conductivity.

USE AND VEGETATION: Most areas are in brush, timber or pasture. Vegetation in uncultivated areas is guava (Psidium guajava), lantana (Lantana camara), joee (Stachytarpheta jamaicensis), sensitive plant (Mimosa pudica), glenwoodgrass (Sacciolepis indica), hilograss (Paspalum conjugatum), Japanese tea (Cassia leschenaultiana), and ferns.

DISTRIBUTION AND EXTENT: Island of Kauai, Kauai County, Hawaii in the eastern and southern part of the island in MLRA 164. Approximately 7,000 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:

Umbric epipedon- the zone from the surface to 25 centimeters (10 inches) (A horizon)

Argillic horizon- the zone from 25 to 127 centimeters (10 to 50 inches) (Bt1, Bt2, Bt3, Bt4 horizons)


National Cooperative Soil Survey
U.S.A.