LOCATION ADJUNTAS PREstablished Series
TAXONOMIC CLASS: Very-fine, kaolinitic, isohyperthermic Inceptic Hapludox
TYPICAL PEDON: Adjuntas clay--in native pasture. (Colors are for moist soil.)
Ap--0 to 5 inches; dark brown (10YR 3/3) clay; moderate fine and medium granular structure; firm; slightly sticky, plastic; many fine roots; about 3 percent, by volume, volcanic fragments 0.25 to 1.0 inch in diameter; few fine quartz grains; many pores; very strongly acid; clear smooth boundary. (4 to 6 inches thick)
Bw1--5 to 10 inches; about 50 percent brown (7.5YR 4/4) and 50 percent strong brown (7.5YR 5/6) clay; weak fine subangular blocky structure; firm; slightly sticky, plastic; common fine roots; about 3 percent, by volume, volcanic fragments 0.25 to 1.0 inch in diameter; few fine quartz grains; many fine pores; very strongly acid; clear smooth boundary. (4 to 7 inches thick)
Bw2--10 to 17 inches; strong brown (7.5YR 5/6) clay; weak fine and medium subangular blocky structure; firm; slightly sticky, plastic; few fine roots; about 3 percent, by volume, volcanic fragments 0.25 to 1.0 inch in diameter; few fine quartz grains; many fine pores; very strongly acid; clear wavy boundary. (6 to 9 inches thick)
Bw3--17 to 24 inches; about 33 percent yellow (10YR 7/6), 33 percent very pale brown (10YR 8/2), and 34 percent brownish yellow (10YR 6/8) clay; weak medium subangular blocky structure; friable; slightly sticky, plastic; few fine roots; many fine pores; many quartz grains; common fine prominent red (2.5YR 4/6) masses of iron accumulation; the colors of yellow, very pale brown, and brownish yellow are inherited from the parent material and are not indicative of wetness or a perched water table; very strongly acid; clear wavy boundary. (6 to 10 inches thick)
Cr--24 to 48 inches; strongly and partially weathered saprolite.
R--48 inches; semi-consolidated volcanic rock.
TYPE LOCATION: Sur SCD, Puerto Rico; approximately 320 meters east of school at dead end of Highway No. 602.
RANGE IN CHARACTERISTICS: Thickness of the solum and depth to the Cr horizon ranges from 20 to 40 inches. Depth to R horizon ranges from 40 to 60 inches. Reaction ranges from extremely acid to strongly acid throughout. Content of pebbles range from 2 to 5 percent, by volume, throughout. Quartz grains range from few to many throughout. Base saturation is less than 50 percent in the cambic horizon.
The A or Ap horizon has hue of 10YR, value of 3 or 4, and chroma of 2 to 4. Texture is clay.
The upper part of the Bw horizon has hue of 7.5YR or 10YR, value of 4 or 5, and chroma of 4 to 8. Texture is clay.
The lower part of the Bw horizon has hue of 7.5YR or 10YR, value of 4 or 5, and chroma of 4 to 8; or there is no dominant color and is multicolored in shades of yellow, white, brown, and red. Relict features inherited form the underlying bedrock in shads of yellow, white, and brown, and red range from common to many.
The Cr horizon is composed of weathered saprolite.
The R horizon is composed of volcanic bedrock.
COMPETING SERIES: Daguey and Zarzal soils are in the same family. Daguey soils are on similar to lower positions and are very deep. Zarzal soils are on higher positions, weathered from sandstone, and are very deep.
GEOGRAPHIC SETTING: Adjuntas soils are on side slopes and narrow ridges at elevations below 550 meters. Slopes range from 40 to 60 percent. They formed in clayey residuum that weathered from volcanic rock. The climate is humid tropical. The average annual precipitation ranges from 80 to 90 inches and the mean annual temperature ranges from 75 to 77 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: In addition to the competing Daguey series, these include the Consejo, Consumo, Humatas, and Maraquez series. Consejo and Maraguez soils are on similar positions, are very deep, and have less clay in the control section. In addition, Maraguez soils have mixed mineralogy. Consumo and Humatas soils are on similar positions, are very deep, and have Umbric epipedons.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Most areas are used for native pasture. The vegetation consists of native and introduced grasses and shrubs.
DISTRIBUTION AND EXTENT: Humid uplands of Puerto Rico. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina.
SERIES ESTABLISHED: Ponce Survey Area, Puerto Rico; 1971.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - the zone from 0 to 5 inches (Ap horizon).
Cambic horizon - the zone from 5 to 24 inches (Bw1, Bw2, and Bw3 horizons).
Paralithic contact - at a depth of 24 inches (Cr horizon).
Lithic contact - at a depth of 48 inches (R horizon).
ADDITIONAL DATA: Characterization data - S73PR-01-1. Sample numbers 74B174-74B179. Sampled by NSSL, Lincoln, NE.