Established Series


The Santa Clara series consists of moderately deep, well drained soils formed in materials weathered from limestone. They are gently sloping to moderately steep soils in foot slopes and rounded hills. These soils are silty clay loam or clay, neutral in the A horizon, silty clay, calcareous in the cambic horizon over a C horizon that is mainly soft limestone.

TAXONOMIC CLASS: Fine, mixed, active, isohyperthermic Typic Eutrudepts

TYPICAL PEDON: Santa Clara silty clay loam - native pasture.
(Colors are for moist soil.)

Ap--0 to 6 inches; very dark grayish brown (10YR 3/2) silty clay loam, strong medium and coarse granular structure; slightly hard, firm, slightly sticky, plastic; many fine roots; neutral; clear smooth boundary. (5 to 10 inches thick)

B--6 to 23 inches; dark yellowish brown (10YR 4/4) silty clay; weak medium and coarse subangular blocky structure; slightly hard, firm slightly sticky, plastic; common fine roots; worm channels; slight effervescence; clear smooth boundary. (15 to 20 inches thick)

C--23 to 30 inches; yellow (10YR 7/6) with few faint very pale brown (10YR 8/3) mottles; massive; friable, slightly sticky, slightly plastic; very few fine roots; violent effervescence with dilute HCL; clear smooth boundary. This horizon is mainly soft limestone. (6 to 10 inches thick)

R--30 plus inches; hard fragmental limestone.

TYPE LOCATION: Norceste SCD, Puerto Rico; one mile south of the town of Isabela; one kilometer on dirt road east of kilometer marker 1.7 on Highway 112; 50 meters south of dirt road.

RANGE IN CHARACTERISTICS: Thickness of the solum ranges from 20 to 30 inches. Depth to the hard fragmental limestone varies from 26 to 40 inches. Base saturation (by NH4OAC) is 80 to 90 percent throughout the profile. The mean annual soil temperature is 75 degrees F.

The A horizon has hues of 10YR or 7.5YR, values and chromas of 2 or 3. Texture is silty clay loam or clay. Structure is moderate or strong, medium or coarse granular. Consistence is slightly sticky or sticky and plastic. Reaction is slightly acid to mildly alkaline.

The B horizon has hues of 7.5YR or 10YR, values of 4 or 5, and chromas of 4 to 6. Texture is silty clay or clay. Structure is moderate weak, fine to coarse subangular blocky. Consistence is slightly sticky or sticky and plastic. Reaction is neutral to moderately alkaline. May have from 5 to 10 percent fine limestone fragments.

The C horizon is a mixture of clay and soft limestone. Consistence is slightly sticky and slightly plastic or plastic.

COMPETING SERIES: The Naranjo series is in the same family level. The Aguilita, Colinas, Fredensborg, Pozo Blanco, Sion, Soller and Yauco series are similar soils in related families. The Naranjo soils are deeper and lack the hard fragmental limestone. The Aguilita soils are coarser textured and have more than 35 percent coarse fragments in their profiles. The Colinas soils are calcareous and are coarser texture over soft limestone. The Fredensborg, Pozo Blanco, Sion and Yauco soils are coarser textured and have ustic moisture regimes. The Soller soils are shallower to hard rock and have thinner sola.

GEOGRAPHIC SETTING: The Santa Clara soils are gently sloping to moderately steep soils on foot slopes and rounded limestone hills with slope gradients of 2 to 25 percent. They formed in moderately fine and fine textured residuum derived from limestone. The climate is humid tropical. The average annual precipitation ranges from 75 to 80 inches and the mean annual temperature is 76 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Camaguey, Colinas, Naranjo, San German, Soller, and Tanama. The Camaguey soils have thicker and darker A horizons, lack cambic horizons, have many slickensides and pressure phases, and are deeper. The Tanama soils are redder and have argillic horizons. The San German soils are coarser textured and lack B horizons.

DRAINAGE AND PERMEABILITY: Well drained, medium runoff, and moderate permeability.

USE AND VEGETATION: Sugarcane and pasture.

DISTRIBUTION AND EXTENT: Humid limestone areas of Puerto Rico. The series is of minor extent, with about 2,000 acres.


SERIES ESTABLISHED: Soil Survey of Puerto Rico; 1942.

National Cooperative Soil Survey
U. S. A.