LOCATION COLOSO PR
Established Series
Rev. GRB; ASR
04/2021
COLOSO SERIES
MLRA(s): 271, 272
Soil Survey Regional Office (SSRO) Responsible: Raleigh, North Carolina
Depth Class: Very deep
Drainage Class (Agricultural): Somewhat poorly drained
Saturated Hydraulic Conductivity: Moderately low
Index Surface Runoff: Slow
Parent Material: Stratified loamy and clayey alluvial sediments
Slope: 0 to 2 percent
Elevation (type location): 11 feet
Mean Annual Air Temperature (type location): 78 degrees F.
Mean Annual Precipitation (type location): 80 inches
TAXONOMIC CLASS: Fine, mixed, active, nonacid, isohyperthermic Vertic Endoaquepts
TYPICAL PEDON: Coloso silty clay loam - sugarcane. (Colors are for moist soil.)
Ap--0 to 7 inches; brown (10YR 4/3) silty clay; 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) clay, 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) clay; 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. USGS Anasco topographic quadrangle; lat. 18 degrees, 16 minutes, 47.36 seconds N; long. 67 degrees, 10 minutes, 0.52 seconds W.
RANGE IN CHARACTERISTICS:
Solum thickness: 10 to 20 inches
Depth to seasonally high water: 6 to 18 inches
Soil Reaction: Moderately alkaline throughout. This soil is moderately saline throughout.
Coarse fragments: Rock fragments range from 0 to 10 percent, by volume, throughout
RANGE OF INDIVIDUAL HORIZONS:
A or Ap horizon:
Color--hue of 7.5YR to 5Y, value of 2.5 to 5, and chroma of 1 to 4
Texture--silty clay loam, silty clay, clay, or clay loam
Bw horizon:
Color--hue of 10YR or 2.5Y, value of 4 or 5, and chroma of 2 to 6
Texture--silty clay loam, silty clay, clay, or clay loam
Redoximorphic features--masses of oxidized iron in shades of yellow, brown, and red range from none to common. Iron depletions in shades of yellow and gray range from few to common
Bg horizon, where present:
Color--hue of 10YR or 2.5Y, value of 4 or 5, and chroma of 0 to 2
Texture--silty clay loam, silty clay, clay, or clay loam
Redoximorphic features--masses of oxidized iron in shades of yellow, brown, and red range from none to common. Iron depletions in shades of yellow and gray range from few to common
C horizon, where present:
Color--hue of 10YR to 5Y, value of 4 to 7, and chroma of 2 to 6
Texture--silty clay loam, clay loam, silty clay or clay
Redoximorphic features--shades of red, yellow, or brown range from few to many. Common to many iron-manganese concretions, nodules, and/or masses.
Cg horizon:
Color--hue of 10YR to 5Y, value of 4 to 7, and chroma of 0 to 2
Texture--silty clay loam, clay loam, silty clay or clay
Redoximorphic features--shades of red, yellow, or brown range from few to many. Common to many iron-manganese concretions, nodules, and/or masses.
2C horizons, when present:
have variegated colors due to redoximorphic features and can be grayish in color.
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 2 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:
Bajura soils--have a depth to water table of 0 to 6 inches; on similar landscape positions
Corcega soils--have a fine-loamy over sandy or sandy-skeletal particle size control section; on similar landscape positions
Dique soils--have a fine-loamy particle size control section, have a depth to water table of greater than 60 inches; on slightly higher landscape positions
Reilly soils--have a sandy skeletal particle size control section and have a water table greater than 60 inches; on slightly higher landscape positions closer to rivers
Toa soils--have a depth to water table of greater than 60 inches and have a mollic epipedon; on slightly higher landscape positions
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage Class (Agricultural): Somewhat poorly drained
Saturated Hydraulic Conductivity: Moderately low
USE AND VEGETATION:
Major Uses: Historically used for sugarcane production, currently most areas are used for pasture.
Dominant Vegetation: Native and introduced species.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Raleigh, North Carolina.
DISTRIBUTION AND EXTENT:
Distribution: River flood plains of Humid Coastal Plains in Puerto Rico
Extent: Moderate
SERIES ESTABLISHED: Soil Survey of Puerto Rico; 1942.
REMARKS: The 2021 update changes the classification from Fine, mixed, active, isohyperthermic Vertic Dystreudepts (2008)
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 conditions - apparent water table; 6 to 18 inches; July through September.
Redoximorphic features- oxidized iron masses, reduced iron masses, and iron-manganese concretion, nodules, and/or masses (mainly in Cg horizon)
ADDITIONAL DATA: Rio Grande Municipality, Puerto Rico; S93PR-119-009 and S93PR-119-012. Samples by KSSL, Lincoln, NE.
National Cooperative Soil Survey
U.S.A.