LOCATION ALGARROBO PREstablished Series
TAXONOMIC CLASS: Coarse-loamy over clayey, siliceous over mixed, subactive, isohyperthermic Entic Alorthods
TYPICAL PEDON: Algarrobo fine sand--coconuts and native pasture (Colors are for moist soil unless otherwise stated).
A--0 to 11 inches; gray (10YR 5/1) fine sand; single grain; loose; nonsticky, nonplastic; many fine and medium roots; about 15 percent, by volume, black (10YR 2/1) rounded and elongated concretions, extremely acid, abrupt smooth boundary. (10 to 16 inches thick)
E--11 to 32 inches; light gray (10YR 7/1) fine sand; single grain; loose; nonsticky, nonplastic; common medium roots; extremely acid, clear wavy boundary. (11 to 21 inches thick)
Bh--32 to 37 inches; stratified black (10YR 2/1), dark brown (10YR 3/3) and very dark brown (10YR 2/2) sandy loam; very friable; nonsticky, nonplastic; few medium roots; extremely acid, abrupt wavy boundary. (3 to 7 inches thick)
Bt--37 to 50 inches; light gray (10YR 7/1) clay; weak coarse subangular blocky structure; extremely firm; extremely hard, slightly sticky, plastic; very dark gray (10YR 3/1) stains along root channels; many prominent brown (7.5YR 5/4) and common distinct yellowish brown (10YR 5/8) masses of iron accumulation; very strongly acid, clear wavy boundary. (10 to 15 inches thick)
C1--50 to 68 inches; light gray (10YR 7/1) clay; massive; extremely firm; slightly sticky, plastic; many distinct brown (7.5YR 5/4) masses of iron accumulation; very strongly acid, clear wavy boundary.
C2--68 to 80 inches; light gray (10YR 7/1) sandy clay loam; massive; very firm; slightly sticky, plastic; very strongly acid.
TYPE LOCATION: Arecibo, Puerto Rico; approximately 300 meters northeast of kilometer marker 2.4 on highway 687.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 40 to 60 inches. Depth to the Bt horizon is more than 37 inches. Reaction ranges from extremely acid to strongly acid throughout. The extremely firm, extremely hard horizons slake in water.
The A or Ap horizon has hue of 10YR, value of 4 to 8, and chroma of 1 or 2. Texture is fine sand or sand.
The E horizon has hue of 10YR, value of 6 or 7, and chroma of 1 or 2. Texture is fine sand or sand.
The Bh horizon has hue of 7.5YR or 10YR, with values of 2 through 4, and chroma of 1 through 3. Some pedons have stratified layers in shades of brown, gray, or black. Texture is loamy sand or sandy loam.
The Bt horizon has hue of 7.5YR or 10YR, value of 5 to 7, and chroma of 1 to 8. Redoximorphic features in shades of brown and red range from few to many. Texture is sandy clay or clay.
The C horizon has hue of 10YR to 2.5Y, value of 4 to 7 and chroma of 1 to 6. Redoximorphic features in shades of brown and red range from few to many. Texture is
COMPETING SERIES: There are no known series in the same family.
GEOGRAPHIC SETTING: Algarrobo soils are on coastal plains. They formed in sands high in quartz that are underlain by clayey coastal plain deposits. Slopes range from 2 to 12 percent. The climate is humid tropical. The average annual precipitation ranges from 55 to 65 inches and the average annual temperature ranges from 77 to 79 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arecibo, Carrizales, Guerrero and Jobos soils. Arecibo, Carrizales, and Guerrero soils are excessively drained. In addition, Arecibo soils are on similar positions and are more than 50 inches in depth to the spodic horizon, Carrizales soils are on higher positions and are sandy throughout, and Guerrero soils are on higher positions, have clayey control sections, and have sandy surface and subsurface layers 20 to 40 inches in thickness. The moderately well drained Jobos soils are on higher positions, have clayey control sections, are plinthic, and have sandy surface and subsurface layers less than 20 inches in thickness.
DRAINAGE AND PERMEABILITY: Well drained; very rapid permeability in the A and E horizons, and slow in the Bh, Bt, and C horizons.
USE AND VEGETATION: Most areas of Algarrobo soils are in native pasture or in coconut production. The vegetation consists of native and introduced species.
DISTRIBUTION AND EXTENT: Northern coastal plains of Puerto Rico. The series is of minor extent, with about 2,000 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina.
SERIES ESTABLISHED: Soil Survey of Puerto Rico, 1942.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - the zone from 0 to 32 inches (A and E horizons).
Albic horizon - the zone from 11 to 32 inches (E horizon).
Spodic horizon - the zone from 32 to 37 inches (Bh horizon).
Argillic horizon - the zone from 37 to 50 inches (Bt horizon).
Following periods of heavy rains, water moves laterally through these soils, mostly through the E horizons.