LOCATION MAKAWAO HIEstablished Series
TAXONOMIC CLASS: Very-fine, parasesquic, isothermic Ustic Palehumults
TYPICAL PEDON: Makawao silty clay - pasture. (Colors are for moist soil unless otherwise noted. All textures are "apparent field textures.")
Ap1--0 to 4 inches; dark reddish brown (5YR 3/3) silty clay, reddish brown (5YR 4/4) dry; strong very fine subangular blocky structure; hard, firm, sticky and plastic; many roots; many very fine pores; slight effervescence with hydrogen peroxide; strongly acid (pH 5.5); clear wavy boundary. (3 to 6 inches thick)
Ap2--4 to 9 inches; dark reddish brown (5YR 3/3) silty clay, yellowish red (5YR 4/6) dry; strong very fine subangular blocky structure; hard, firm, sticky, plastic, and weakly smeary; many roots; common fine pores; slight effervescence with hydrogen peroxide; moderately acid (pH 6.0); abrupt wavy boundary. (3 to 7 inches thick)
Bt1--9 to 12 inches; dark reddish brown (2.5YR 3/4) silty clay, reddish brown (2.5YR 4/4) dry; moderate fine and medium subangular blocky structure; hard, friable, sticky, plastic, and weakly smeary; few roots; many fine and very fine pores; thin patchy clay films on peds; few weathered pebbles; slightly acid (pH 6.4); clear wavy boundary. (2 to 4 inches thick)
Bt2--12 to 19 inches; dark reddish brown (2.5YR 3/4) silty clay, reddish brown (2.5YR 4/4) dry; moderate fine and very fine subangular blocky structure; slightly hard, friable, sticky, plastic, and weakly smeary; few roots; many fine and very fine pores; thin continuous clay films on peds; 10 to 15 percent by volume weathered pebbles; slightly acid (pH 6.4); gradual wavy boundary. (5 to 9 inches thick)
BC--19 to 37 inches; dark reddish brown (5YR 3/4) silty clay, reddish brown (5YR 5/4) dry; moderate fine and very fine subangular blocky structure; slightly hard, friable, sticky, plastic and moderately smeary; few roots; many fine and medium pores; continuous gelatin-like coatings on peds; 10 to 15 percent by volume weathered pebbles; slightly acid (pH 6.5); gradual wavy boundary. (15 to 20 inches thick)
C--37 to 60 inches; gray highly weathered rock and 15 to 20 percent dark brown (10YR 3/3) silty clay, brown (10YR 5/3) dry; weak fine and medium subangular block structure; hard, firm, sticky, plastic, moderately smeary; few roots; common fine and medium pores; slightly acid (pH 6.5).
TYPE LOCATION: Island of Maui, Maui County, Hawaii; Haiku Quadrangle - 20 degrees 51 minutes 02 seconds north latitude and 156 degrees 18 minutes 36 seconds west longitude, 150 feet east of Olinda Road and 0.5 miles south of Makawao.
RANGE IN CHARACTERISTICS: Depth to bedrock is more than 40 to 60 inches. Smeariness ranges from weak in pedons at lower elevations to moderate in pedons at higher elevations.
The A horizon has value of 4 or 5 dry, and chroma of 2 or 3 moist, 4 through 6 dry.
The Bt horizon has hue of 5YR or 2.5YR, value of 3 or 4 moist, 4 or 5 dry, and chroma of 3 or 4 moist, 3 through 5 dry. It is silty clay or clay.
COMPETING SERIES: This is the Honolua series. Honolua soils have thick patchy clay films, are strongly acid in the argillic horizon, and are not smeary in the lower part of the argillic horizon.
GEOGRAPHIC SETTING: Makawao soils are on uplands. Slopes range from 3 to 15 percent. Elevation ranges from 1,200 to 2,500 feet. The soils formed in residuum from basic igneous rock and volcanic ash. Average annual rainfall is 60 to 90 inches. Mean annual temperature is about 69 degrees F.; average January temperature is 66 degrees F.; and average July temperature is 72 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Haiku, Haliimaile, Kailua, Olinda and Pauwela soils. Haiku soils have an argillic horizon that contains many gibbsite nodules. Haliimaile, Kailua, and Olinda soils do not have an argillic horizon. Pauwela soils have 10YR or yellower hue in the A horizon, and have gibbsite nodules or sheets and moderately thick clay films in the argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff depending on slope; moderately rapid permeability.
USE AND VEGETATION: These soils are used for pasture and a few small areas are in pineapple. The vegetation is bermudagrass (Cynodon dactylon), eucalyptus (Eucalyptus spp.), guava (Psidium guajava), hilograss (Paspalum conjungatum), kaimi clover (Desmodium canum), kikuyugrass (Pennisetum clandestinum), and yellow foxtail (Setaria geniculata).
DISTRIBUTION AND EXTENT: Island of Maui, Hawaii. This series is of small extent comprising about 1,900 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:
umbric epipedon- The zone from the surface to 9 inches (Ap1, Ap2)
argillic horizon- The zone from 9 to 19 inches (Bt1, Bt2))