LOCATION GUAMANI PREstablished Series
TAXONOMIC CLASS: Fine-loamy over sandy or sandy-skeletal, mixed, superactive, isohyperthermic Torrifluventic Haplustepts
TYPICAL PEDON: Guamani silty clay loam - sugar cane. (Colors are for moist soil.)
Ap--0 to 6 inches; very dark grayish brown (10YR 3/2) silty clay loam; weak fine subangular blocky separating to fine granular structure; friable; slightly plastic, slightly sticky; many fine roots; few fine pores; few fine rock fragments; slightly acid; gradual smooth boundary. (4 to 8 inches thick)
Bw--6 to 20 inches; brown (10YR 4/3) silty clay loam; weak fine subangular blocky structure; friable; slightly plastic, slightly sticky; common fine roots; common fine pores; few rock fragments and gravel; slightly acid; abrupt wavy boundary. (11 to 26 inches thick)
2C--20 to 80 inches; alternating layers of sand, pebbles, and cobbles; slightly acid.
TYPE LOCATION: Sudeste SCD, Puerto Rico, Highway 3, between Guayama and Salinas; about 100 feet west to kilometer marker 144.3.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 15 to 34 inches. Reaction ranges from slightly acid to slightly alkaline throughout.
The A or Ap horizon has hue of 10YR, value of 2 or 3, and chroma of 2 or 3. Texture is sandy loam, fine sandy loam, loam, silt loam, silty clay loam, or clay loam.
The Bw horizon has hue of 7.5YR or 10YR, value of 4 or 5, and chroma of 2 or 3. Texture is fine sandy loam, loam, silt loam, silty clay loam, or clay loam.
The 2C horizon is a mixture of sand, pebbles, and cobbles. Some pedons have hue of 10YR, value of 3 or 4, and chroma of 2 to 4 with stratified layers of sand, loamy sand, loamy fine sand, sandy loam, or loam.
COMPETING SERIES: There are no other known series in the same family.
GEOGRAPHIC SETTING: Guamani soils are on river flood plains of southern Puerto Rico. They formed in medium-textured sediments over sand, pebbles, and cobbles derived from volcanic and limestone rocks. The climate is tropical semiarid. Slopes range from 0 to 2 percent. The average annual temperature ranges from 78 to 80 degrees F., and the average annual rainfall ranges from 35 to 45 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Aguirre, Arenales, Fraternidad, San Anton, and Vayas soils. The somewhat poorly drained Aguirre and moderately well drained Fraternidad soils are on higher positions and have clayey, smectitic control sections. Arenales soils are on similar positions, have sandy control sections, and lack cambic horizons. San Anton soils are on slightly higher positions, have mollic epipedons, and fine-loamy subsoils. The poorly drained Vayas soils are on lower positions and have clayey subsoils.
DRAINAGE AND PERMEABILITY: Well drained; rapid permeability.
USE AND VEGETATION: Most areas of Guamani soils are used for cropland and pasture. Vegetation consists of guineagrass and other native and introduced grasses.
DISTRIBUTION AND EXTENT: In the semiarid river flood plains of Puerto Rico. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina.
SERIES ESTABLISHED: Sudeste Soil Conservation District, Puerto Rico; l969.
REMARKS: The Guamani series was formerly classified in the Alluvial great soil group.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 6 inches.
Cambic horizon - the zone from 6 to 20 inches.
Below 20 inches - stratified layers of sand, pebbles, and cobbles.