LOCATION COLOSO PREstablished Series
TAXONOMIC CLASS: Fine, mixed, active, isohyperthermic Vertic Dystrudepts
TYPICAL PEDON: Coloso silty clay loam - sugarcane. (Colors are for moist soil.)
Ap--0 to 7 inches; brown (10YR 4/3) silty clay loam; weak medium granular structure; firm, slightly sticky, plastic; many fine roots; few worm holes; slightly acid; clear smooth boundary. (5 to 12 inches thick)
Bw--7 to 13 inches; brown (10YR 4/3) silty clay loam, weak fine subangular blocky structure; firm, slightly sticky, slightly plastic; common fine roots; few worm holes; few fine black (10YR 2/1) concretions; common fine distinct yellowish red (5YR 4/6) masses of iron accumulation and common fine faint light gray (10YR 7/2) areas of iron depletion; slightly acid; clear smooth boundary. (0 to 10 inches thick)
Cg1--13 to 33 inches; about 50 percent dark gray (10YR 4/1) and 50 percent light gray (5Y 7/1) silty clay loam; massive; firm, slightly sticky, plastic; few fine roots; few worm holes; common fine black (10YR 2/1) concretions; many medium distinct reddish brown (5YR 4/3) masses of iron accumulation; the areas in colors of dark gray and light gray are iron depletions; slightly acid; gradual smooth boundary. (15 to 25 inches thick)
Cg2--33 to 60 inches; dark gray (10YR 4/1) silty clay; massive; firm, slightly sticky, plastic; few fine roots; few worm holes; common fine black (10YR 2/1) concretions; many fine faint yellowish brown (10YR 5/8) masses of iron accumulation and common fine distinct greenish gray (5GY 5/1) areas of iron depletion; slightly acid.
TYPE LOCATION: Oeste SCD, Puerto Rico. Approximately one kilometer west of the town of Anasco; about 250 meters west of kilometer marker 145.5 of Highway 2, and fifty feet north of farm road.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 7 to 22 inches. Rock fragments range from 0 to 10 percent by volume throughout the profile. Reaction ranges from moderately acid to slightly acid throughout the profile.
The A or Ap horizon have hue of 7.5YR to 5Y, value of 2.5 to 5, and chroma of 1 to 4. Texture is silty clay loam or silty clay.
The Bw horizons have hue of 10YR or 2.5Y, value of 4 or 5, and chroma of 3 to 6. Redoximorphic features in shades of red, yellow, brown, or gray range from few to many. Texture is silty clay loam, silty clay, or clay.
The C or Cg horizon has hue of 10YR to 5Y, value of 4 to 7, and chroma of 1 to 4. Redoximorphic features in shades of red, yellow, or brown range from few to many. Texture is silty clay loam, clay loam, silty clay or clay.
COMPETING SERIES: There are no other known series in the same family.
GEOGRAPHIC SETTING: Coloso soils are on river flood plains and low terraces. They formed in stratified loamy and clayey alluvial sediments of mixed origin. Slopes range from 0 to 8 percent. The climate is humid tropical. The average annual precipitation ranges from 78 to 82 inches and the mean annual air temperature is 77 to 79 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Bajura, Corcega, Dique, and Toa series. The poorly drained Bajura soils have mixed mineralogy and Vertic subgroups. Corcega soils are fine-loamy over sandy or sandy-skeletal. The well drained Dique soils are fine-loamy. The well drained Toa soils have mixed mineralogy and a Mollic epipedon.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow permeability.
USE AND VEGETATION: Most areas of Coloso soils are used for sugarcane production. Some areas are used for pasture. A few areas are in woodland consisting of native and introduced species.
DISTRIBUTION AND EXTENT: Humid river flood plains of Puerto Rico. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Auburn, Alabama.
SERIES ESTABLISHED: Soil Survey of Puerto Rico; 1942.
REMARKS: Diagnostic horizons and features recognized in this pedon.
Ochric epipedon - the zone from 0 to 7 inches (Ap horizon).
Cambic horizon - the zone from 7 to 13 inches (Bw horizon).
Aquic feature - apparent water table; 2 to 4 feet; July through September.
Coloso soils are in MLRAs 270 and 272.
ADDITIONAL DATA: Rio Grande Municipality, Puerto Rico; S93PR-119-009 and S93PR-119-012. Samples by NSSL, Lincoln, NE.