LOCATION GUAYABO PREstablished Series
TAXONOMIC CLASS: Mixed, superactive, isohyperthermic Arenic Paleargids
TYPICAL PEDON: Guayabo sand--wildlife habitat (Colors are for moist soil).
Ap--0 to 7 inches; brown (10YR 5/3) sand; single grained; loose; nonsticky, nonplastic; slightly acid; clear smooth boundary. (4 to 8 inches thick)
E1--7 to 13 inches; pale brown (10YR 6/3) sand; single grained; loose; nonsticky, nonplastic; slightly acid; clear smooth boundary.
E2--13 to 18 inches; pale brown (10YR 6/3) fine sand; single grained; loose; nonsticky, nonplastic; common medium faint strong brown (7.5YR 5/6) stains in root channels; slightly acid; clear smooth boundary.
E3--18 to 35 inches; very pale brown (10YR 7/3) sand; single grained; loose, loose; nonsticky and nonplastic; few fine faint strong brown (7.5YR 5/6) stains in root channels; slightly acid; gradual wavy boundary.
E4--35 to 55 inches; very pale brown (10YR 7/3) sand; single grained; loose; nonsticky, nonplastic; slightly acid; gradual wavy boundary. (Combined thickness of the E horizons range from 32 to 54 inches.)
EB--55 to 65 inches; very pale brown (10YR 7/4) fine sand; single grained; loose; nonsticky, nonplastic; about 1 percent, by volume, pebbles; few fine distinct yellowish red (5YR 5/6) masses of iron accumulation; neutral; clear smooth boundary. (3 to 10 inches thick)
Bt--65 to 80 inches; about 34 percent strong brown (7.5YR 5/6), about 33 percent pale brown (10YR 6/3) and about 33 percent red (2.5YR 4/6) loamy sand; very friable; nonsticky, nonplastic; few faint clay films between sand grains; about 10 percent, by volume, pebbles; neutral.
TYPE LOCATION: Cabo Rojo, Puerto Rico. Approximately 2.2 miles southwest of the intersection of P.R. Hwy. 301 and P.R. Hwy. 303; about 0.5 mile south of Pole Ojea community from the intersection of P.R. Hwy. 301 and P.R. Hwy. 3301; about 1200 feet northwest of dirt road on wildlife habitat. USGS Cabo Rojo topographic quadrangle (1966); lat. 17 degrees 58 minutes 22 seconds N.; long. 67 degrees 11 minutes 00 seconds W.
RANGE IN CHARACTERISTICS: Solum thickness is more than 60 inches. Content of rock fragments range from 0 to less than 15 percent, by volume, throughout. Reaction ranges from slightly acid to slightly alkaline throughout.
The Ap or A horizon has hue of 10YR, value of 3 to 5, and chroma of 2 to 4. Texture is sand.
The E horizon has hue of 7.5YR to 2.5Y, value of 5 to 7, and chroma of 3 to 6. Texture is sand.
The EB horizon, where present, has hue of 10YR, value of 4 to 7, and chroma of 4 to 6. Content of iron accumulations in shades of red, yellow and brown range from few to common. Texture is loamy sand or sandy loam.
The Bt horizon have hue of 7.5YR to 2.5Y, value of 4 to 6, and chroma of 3 to 6; or there is no dominant color and is multicolored in shades of brown and red. Texture is loamy sand, loamy fine sand, sandy loam sandy, clay loam, or sandy clay.
COMPETING SERIES: There are no other known series in the same family.
GEOGRAPHIC SETTING: Guayabo soils are on coastal plains of the Semiarid Coastal Plains MLRA of southern Puerto Rico. Slopes range from 0 to 5 percent. They formed in sandy marine deposits. The climate is semiarid tropical. The average annual precipitation range from 30 to 40 inches and the average annual temperature ranges from 78 to 82 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Bahia and Sosa series. Bahia soils are on similar positions but have kaolinitic mineralogy. Sosa soils have fine particle-size control sections.
DRAINAGE AND PERMEABILITY: Excessively drained; rapid permeability.
USE AND VEGETATION: Most areas of Guayabo soils are used for wildlife habitat and urban development. Some small areas are used for pasture and cultivated crops including sorghum, corn, sweet potatoes and watermelons. The vegetation consists of native and introduced grasses and shrubs.
DISTRIBUTION AND EXTENT: Southwestern coastal plains of Puerto Rico. The series is small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina.
SERIES ESTABLISHED: Puerto Rico; 1936.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - the zone from 0 to 55 inches (Ap, A1, A2, A3 and A4 horizons).
Argillic horizon - the zone from 65 to 75 inches (Bt horizon).
The classification was updated with the 11/2004 draft from Mixed, isohyperthermic Psammentic Paleustalfs to Mixed, isohyperthermic Arenic Paleargids based on a soil moisture study which recognize the Aridic Soil Moisture Regime in southern Puerto Rico.
ADDITIONAL DATA: Characterization pedon - Cabo Rojo Municipality, Puerto Rico; S81PR-007-002. Sample by NSSL, Lincoln, NE., 08/1981.
Guayabo soils are in MLRA 273.