LOCATION ARECIBO PREstablished Series
TAXONOMIC CLASS: Sandy, siliceous, isohyperthermic Entic Grossarenic Alorthods
TYPICAL PEDON: Arecibo fine sand - Pangola grass and coconut palms (Colors are for moist soil unless otherwise stated.)
A1--0 to 6 inches; gray (10YR 5/1) fine sand; single grain; loose; nonsticky, nonplastic; many fine roots; many round black (10YR 2/1) concretions; very strongly acid; clear smooth boundary.
A2--6 to 12 inches; gray (10YR 6/1) fine sand; single grain; loose; nonsticky, nonplastic; many fine roots; common round black (10YR 2/1) concretions; very strongly acid; clear wavy boundary. (Combined thickness of the A horizons range from 8 to 16 inches)
E1--12 to 20 inches; light gray (10YR 7/1) fine sand; single grain; loose; nonsticky, nonplastic, few fine roots; very strongly acid; clear wavy boundary.
E2--20 to 40 inches; white (10YR 8/1) fine sand; single grain; loose; nonsticky, nonplastic; few fine roots; very strongly acid; diffuse wavy boundary.
E3--40 to 59 inches; white (10YR 8/1) fine sand; single grain; loose; nonsticky, nonplastic; common decayed roots; many medium brown (10YR 5/3) masses and splotches of organic matter accumulation; very strongly acid; clear wavy boundary. (Combined thickness of the E horizons range from 40 to 58 inches)
Bw--59 to 68 inches; brown (10YR 5/3) fine sand; single grain; loose; nonsticky, nonplastic; very strongly acid; abrupt wavy boundary. (7 to 11 inches thick)
Bh1--68 to 74 inches; stratified black (10YR 2/1), very dark grayish brown (10YR 3/2) and very dark brown (10YR 2/2) sand; the black layer is the uppermost and is 1 cm thick; single grain; loose; nonsticky, nonplastic; very strongly acid; clear wavy boundary.
Bh2--74 to 82 inches, yellowish brown (10YR 5/6) loamy sand; single grain; loose; nonsticky, nonplastic; about 15 percent, by volume, thin black (10YR 2/1) lamellae, 1 to 3 cm wide and 8 cm apart; very strongly acid; clear wavy boundary. (Combined thickness of the Bh horizons range from 10 to 18 inches)
Bw1--82 to 88 inches, 25 percent very pale brown (10YR 8/4), 25 percent white (10YR 8/1), 25 percent brown (10YR 5/3), and 25 percent reddish yellow (7.5YR 6/8) sandy loam; massive; slightly sticky, slightly plastic; extremely firm; about 60 percent of the horizon is strongly cemented; few tongues of Bh material; the areas of very pale brown and white are iron and organic matter depletions and the areas of brown and reddish yellow are iron and organic matter accumulations; very strongly acid; gradual wavy boundary.
Bw2--88 to 91 inches, 25 percent very pale brown (10YR 8/4), 25 percent white (10YR 8/1), 25 percent brown (10YR 5/3), and 25 percent reddish yellow (7.5YR 6/8) loamy sand; massive; slightly sticky, slightly plastic; extremely hard, extremely firm; about 60 percent of the horizon is very strongly cemented; the areas of very pale brown and white are iron and organic matter depletions and the areas of brown and reddish yellow are iron and organic matter accumulations; very strongly acid; clear wavy boundary. (Combined thickness of the Bw horizons range from 6 to 13 inches)
Cg--91 to 113 inches, 50 percent white (5Y 8/1) and 50 percent light gray (5Y 7/2) loamy sand; single grain; loose; nonsticky, nonplastic; distinct sulfide smell; very strongly acid.
TYPE LOCATION: Norte SCD, Puerto Rico; approximately 600 meters west of kilometer marker 15.2 of P.R. Highway 686.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 60 to more than 80 inches. Depth to the Bh horizons ranges from 50 to 80 inches. Reaction ranges from extremely acid to very strongly acid throughout. The extremely firm, extremely hard horizons slake in water.
The A or Ap horizon has hue of 10YR, value of 5 to 8, and chroma of 1 or 2. Texture is fine sand or sand.
The E horizon has hue of 10YR, value of 6 to 8, and chroma of 1 or 2. Organic matter accumulations in shades of brown range from none to common in the lower horizons. Texture is fine sand or sand.
The Bh horizon has hue of 7.5YR or 10YR, value of 2 to 5, and chroma of 1 to 8; or it is stratified in these colors. Texture is loamy fine sand or loamy sand.
The Bw horizon has hue of 7.5YR or 10YR, value of 4 to 8, and chroma of 1 to 8. Texture is loamy fine sand, loamy sand, or sandy loam.
The Bw horizon has hue of 7.5YR or 10YR, value of 4 to 8, and chroma of 1 to 8; or there is no dominant color and it is multicolored in shades of brown, yellow, red, gray, and white. Texture is loamy fine sand, loamy sand, or sandy loam.
The Cg horizon, where present, has hue of 10YR, value of 5 or 6, and chroma of 1 or 2; or there is no dominant color and is mixed in shades of brown, yellow, gray, and white. Texture is fine sand or sand.
COMPETING SERIES: There are no known series in the same family.
GEOGRAPHIC SETTING: Arecibo soils are on coastal plains at low elevations above sea level. Slopes range from 2 to 12 percent. They formed in sands that are high in quartz and underlain by coastal plain deposits. The climate is humid tropical. The average annual precipitation ranges from 55 to 65 inches and the mean annual temperature ranges from 76 to 80 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Carrizales, Guerrero and Jobos soils. All of these soils are on similar to slightly higher positions and do not have Bh horizons. Carrizales soils are sandy throughout. The well drained Guerrero soils have sandy surface and subsurface layers 20 to 40 inches thick and have clayey control sections. The moderately well drained Jobos soils have clayey control sections.
DRAINAGE AND PERMEABILITY: Excessively drained; very rapid permeability.
USE AND VEGETATION: Most areas of Arecibo soils are used for pasture or for coconut plantations. The vegetation consists of Pangola grass, coconuts, and other native and introduced plants.
DISTRIBUTION AND EXTENT: Northern coastal plains. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina.
SERIES ESTABLISHED: Arecibo Soil Survey Area, Puerto Rico.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - the zone from 0 to 12 inches (A1 and A2 horizons).
Albic horizon - the zone from 12 to 59 inches (E1, E2, and E3 horizons).
Spodic horizon - the zone from 59 to 82 inches (Bh1 and Bh2 horizons).
Following periods of heavy rains, water moves laterally through these soils, mostly through the E horizons.
ADDITIONAL DATA: Characterization data is available on the typical pedon; sample No. S73PR-07-02, lab. No. 74B111-74B122. Characterization data by NSSL, Lincoln, NE.