LOCATION TANAMA PREstablished Series
TAXONOMIC CLASS: Clayey, mixed, active, isohyperthermic Lithic Hapludalfs
TYPICAL PEDON: Tanama clay - sugarcane. (Colors are for moist soil.)
Ap--0 to 4 inches; dark reddish brown (5YR 3/4) clay; moderate fine and medium granular structure; firm, slightly sticky, plastic; many fine roots; common fine and medium limestone fragments; slightly acid; clear smooth boundary. (3 to 5 inches thick)
Bt1--4 to 11 inches; reddish brown (5YR 4/4) clay; moderate medium subangular blocky structure; firm, slightly sticky, plastic; common fine roots; few faint clay films; slightly acid; abrupt wavy boundary. (5 to 9 inches thick)
Bt2--11 to 16 inches; reddish brown (5YR 5/4) clay with reddish brown (5YR 4/4) coatings in exterior of peds; moderate medium subangular blocky structure; firm, slightly sticky, plastic; common fine roots; few faint clay films; slightly acid. (4 to 6 inches thick)
R--16 inches; hard limestone.
TYPE LOCATION: Noroeste SCD, Puerto Rico; 2 miles southwest of the town of Aguada. 1.2 miles on dirt road west of kilometer marker 24.9 on Highway 115 (old Highway 2).
RANGE IN CHARACTERISTICS: Thickness of the solum and depth to the hard limestone ranges from 12 to 20 inches. Texture is clay in the whole profile. Consistence is slightly sticky and plastic throughout. Reaction ranges from slightly acid to neutral. The mean annual soil temperature is 75 degrees F.
The A horizon has hues of 5YR or 7.5YR, values and chromas of 3 or 4. Structure is weak or moderate, fine and medium granular.
The Bt horizon has hues of 5YR or 2.5YR, values of 3 or 5, and chromas of 4 to 6. Structure is moderate fine or medium subangular blocky. Clay films range from few faint to many distinct.
COMPETING SERIES: There are no other known series in the same family. The Caracoles, Islote, Juncal, Rio Lajas, San German, San Sebastian and Teja series are similar soils in related families. The Caracoles, San German, and Teja soils lack B horizons. The Islote soils are deeper to the calcareous sandstone. The Juncal soils have thicker argillic horizons. The Rio Lajas soils are sandy throughout. The San Sebastian are calcareous and have more than 35 percent coarse fragments in their profiles.
GEOGRAPHIC SETTING: The Tanama soils are gently sloping to very steep soils on foot slopes and side slopes of limestone hills with slope gradients of 2 to 60 percent. They formed in fine textured residuum derived from limestone. The climate is humid tropical. The average annual precipitation is 70 inches and the mean annual temperature is 76 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing San Sebastian and the San German series. The San Sebastian soils are deeper, very gravelly and calcarous. The San German soils are shallower, calcareous, and lack argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained, medium to rapid runoff, and moderate permeability.
USE AND VEGETATION: Gentler slopes are in sugarcane. Steeper slopes are in pasture and brush. Small areas are in food crops.
DISTRIBUTION AND EXTENT: Along the north coastal plains of Puerto Rico. The series is of moderate extent, with about 75,000 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina
SERIES ESTABLISHED: Soil Survey of Puerto Rico; 1942.
REMARKS: The classification was updated with the 4/91 draft from Clayey, mixed, isohyperthermic Lithic Tropudalfs to Clayey, mixed, isohyperthermic Lithic Hapludalfs. The previous OSED date was 11/75.
Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - zone from 0 to 4 inches (Ap horizon)
Argillic horizon - zone from 4 to 16 inches (Bt horizons)
Lithic contact - zone at 16 inches (R layer)