LOCATION ARENALES           PR
Established Series
Rev. GRB
09/2002

ARENALES SERIES


The Arenales series consists of very deep, excessively drained, rapidly permeable soils on flood plains and alluvial fans. They formed in stratified coarse sediments derived from volcanic and limestone rocks. Near the type location, the mean annual precipitation is about 42 inches and the mean annual temperature is about 79 degrees F. Slopes range from 0 to 2 percent.

TAXONOMIC CLASS: Mixed, isohyperthermic Aridic Ustipsamments

TYPICAL PEDON: Arenales sandy loam - cultivated; sugarcane (colors are for moist soil.)

Ap--0 to 8 inches, very dark grayish brown (10YR 3/2) sandy loam; weak fine granular structure; very friable, nonsticky, nonplastic; many fine roots; common fine subrounded volcanic fragments; slightly alkaline; clear wavy boundary. (6 to 10 inches thick)

C1--8 to 24 inches, very dark grayish brown (10YR 3/2) loamy sand; single grain; loose; nonsticky, nonplastic; few fine roots; thin strata of dark grayish brown (10YR 4/2) loamy sand; moderately alkaline; abrupt smooth boundary.

C2--24 to 31 inches, very dark grayish brown (10YR 3/2) coarse sand; single grain; loose, nonsticky, nonplastic; moderately alkaline; abrupt smooth boundary.

C3--31 to 42 inches, very dark grayish brown (10YR 3/2) sand; single grain; loose, nonsticky, nonplastic; slightly alkaline; clear smooth boundary.

2C--42 to 60 inches; brown (10YR 4/3) extremely gravelly coarse sand; slightly alkaline.

TYPE LOCATION: Sudeste SCD, Puerto Rico. Approximately 0.5 miles south and about 50 feet west of kilometer marker 92.1 of Highway No. 1, near the town of Salinas.

RANGE IN CHARACTERISTICS: The 10 to 40 inch section of the profile is well graded, ranging from silts to coarse sand and gravel. Coarse fragments are less than 35 percent, by volume in the control section. Depth to the gravel and sand layer is 40 to 55 inches. Reaction ranges from slightly acid to moderately alkaline throughout.

The A or Ap horizon has hue of 7.5YR or 10YR, value of 3 and 4, and chroma of 1 through 4. Texture is loam or sandy loam.

The C horizon has hue of 10YR or 7.5YR, value of 3 to 5 and chroma of 2 to 6. Texture is sand, loamy sand, or their gravelly analogs.

The 2C horizon, or 3C horizon, where present, has colors similar to the C horizon. Texture is very gravelly or extremely gravelly fine to coarse sand or sand.

COMPETING SERIES: This is the Meros series in the same family. Meros soils are on benches along the coast and have poorly graded, well sorted soil materials dominated by sand-size sea shell and coral fragment.

GEOGRAPHIC SETTING: Arenales soils are on flood plains and alluvial fans. They formed in stratified, coarse-textured sediments derived from volcanic and limestone rocks. Slopes range from 0 to 2 percent. The climate is semiarid tropical. The average annual precipitation ranges from 35 to 50 inches and the average annual air temperature ranges from 78 to 80 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Guamani, Jacaguas, San Anton, and Vayas series which occur in the flood plain. Guamani soils are on similar positions but have a cambic horizon and a control section that is loamy in the upper part and gravelly in the lower part. Jacaguas soils are on similar topographic positions close to the streams but have mollic epipedons and more than 35 percent coarse fragments throughout. The well drained San Anton soils are on slightly higher positions and have mollic epipedons. The poorly drained Vayas soils are on lower positions and are clayey.

DRAINAGE AND PERMEABILITY: Excessively drained; rapid permeability.

USE AND VEGETATION: Many areas are used for the production of sugarcane and pastureland. Vegetation includes guineagrass and other native and introduced species.

DISTRIBUTION AND EXTENT: Semiarid flood plains and alluvial fans of southern Puerto Rico. The series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina.

SERIES ESTABLISHED: Humacao Survey Area, Puerto Rico; September 1969.

REMARKS: These soils were included in the San Anton series in the 1942 Soil Survey of Puerto Rico.

Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon: zone from 0 to 8 inches (Ap horizon)


National Cooperative Soil Survey
U.S.A.