LOCATION TUQUE                   PR

Established Series
ASR\RBT
06/2022

TUQUE SERIES

MLRA(s): 271
MLRA Soil Survey Regional Office (SSRO) Responsible: Raleigh, North Carolina
Depth Class: Shallow
Drainage Class: Well drained
Saturated Hydraulic Conductivity: Low to moderately low
Parent Material: Limestone residuum and bedrock
Slope: 12 to 60 percent
Mean Annual Air Temperature: 26 degrees C. (79 degrees F.)
Mean Annual Precipitation: 711 millimeters (28 inches)

TAXONOMIC CLASS: Clayey, carbonatic, isohyperthermic, shallow Ustic Petrocalcids

TYPICAL PEDON: Tuque gravelly clay--wildlife habitat area (Colors are for moist soil unless otherwise indicated).

A--0 to 13 cm (0 to 5 inches); dark reddish brown (2.5YR 3/4) gravelly clay; weak fine granular structure; friable; slightly sticky, slightly plastic; many fine and medium roots; 30 percent, by volume, limestone gravel; 25 percent shell fragments; moderately alkaline; clear wavy boundary. (10 to 15 centimeters, 4 to 6 inches thick)

Bw--13 to 28 cm (5 to 11 inches); dark red (2.5YR 3/6) gravelly clay; weak fine and medium subangular blocky structure parting to weak fine granular; firm; slightly sticky, slightly plastic; 30 percent, by volume, limestone gravel; moderately alkaline; violently effervescent; clear wavy boundary. (10 to 20 centimeters, 4 to 8 inches thick)

Bkm--28 to 48 cm (11 to 19 inches); very pale brown (10YR 8/3) indurated petrocalcic material with brownish yellow (10YR 6/6) stratified layers; massive; extremely hard, extremely firm, brittle; moderately alkaline; violently effervescent; gradual wavy boundary. (10 to 20 centimeters, 4 to 8 inches thick)

C--48 to 61 cm (19 to 24 inches); strong brown (7.5YR 5/6) gravelly clay; massive; firm; slightly sticky, slightly plastic; 30 percent, by volume, limestone gravel; moderately alkaline; violently effervescent; gradual wavy boundary. (0 to 20 centimeters, 0 to 8 inches thick)

Cr--61 to 152+ cm (24 to 60+ inches); soft limestone bedrock.

TYPE LOCATION: Ponce, Puerto Rico. Approximately 0.7 mile west of El Tuque community from the intersection of P.R. Hwy. 2 and P.R. Hwy. 591; about 1,191 feet northwest of El Tropical Casino Ponce in a wildlife habitat area. USGS Punta Cucharas topographic quadrangle (1982); lat. 17 degrees 58 minutes 52 seconds N.; long. 66 degrees 40 minutes 23 seconds W.

RANGE IN CHARACTERISTICS:
Depth to indurated petrocalcic horizon: Ranges from 25 to less than 50 centimeters (10 to 20 inches)
Reaction: Slightly alkaline to moderately alkaline throughout
Rock fragments: 0 to 43 percent fragments throughout, but no more than 34 percent in particle size control section
Range of Individual Horizons:
A horizon:
Color - Hue of 2.5YR or 5YR, value of 3, and chroma of 3 or 4
Rock fragments - Range from 25 to 50 percent, by volume
Texture - Dominantly clay in the fine-earth fraction

Bw horizon:
Color - Hue of 2.5YR, value of 3, and chroma of 4 or 6
Rock fragments - Range less than 35 percent, by volume
Texture - Dominantly clay in the fine-earth fraction

Bkm horizon:
Composed of indurated petrocalcic material
Color - Hue of 10YR, value of 8, and chroma of 3 to 6
It cannot be excavated with hand tools, but is rippable by mechanized equipment

C horizon: (where present)
Color - Hue of 7.5YR to 2.5Y, value of 4 to 6, and chroma of 4 to 6
Rock fragments - Range from 25 to 50 percent, by volume
Texture - Clay loam or clay in the fine-earth fraction

Cr horizon:
Composed of soft limestone bedrock. It can be excavated with difficulty with hand tools and is rippable by mechanized equipment

COMPETING SERIES: There are no known series in the same family.

GEOGRAPHIC SETTING:
Landscape: Limestone hills of the Semiarid Mountains and Valleys of Puerto Rico (MLRA 271)
Landform: Ridge tops, summits, and side slopes
Parent material: They formed in residuum that weathered from limestone bedrock
Mean Annual Air Temperature: 26 to 30 degrees C. (79 to 86 degrees F.)
Mean Annual Precipitation: 686 to 1143 millimeters (27 to 45 inches)

GEOGRAPHICALLY ASSOCIATED SOILS:
These are the Costa, La Covana, Pitahaya and Seboruco series. All of these soils with the exception of La Covana series are on similar positions but do not have a petrocalcic horizon.
Costa soils--do not have a petrocalcic horizon and also lack cambic horizons.
La Covana soils--have a calcic horizon and do not have a paralithic contact below the petrocalcic horizon within a depth of 60 inches and is in the clayey- skeletal family.
Pitahaya soils--do not have a petrocalcic horizon and also lack cambic horizons.
Seboruco soils--have both argillic and calcic horizons and lack petrocalcic horizons.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: Well drained
Saturated hydraulic conductivity (Ksat): Low to moderately low

USE AND VEGETATION:
Major uses: Most areas of Tuque soils are on naturalized pastureland and wildlife habitat.
Dominant vegetation: The vegetation consists of Mezquite and other xerophytic grasses, shrubs and trees.

DISTRIBUTION AND EXTENT: Ridge tops, summits and side slopes of limestone hills of the semiarid mountains and valleys of southern Puerto Rico (MLRA 271). The series is small extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Raleigh, North Carolina.

SERIES ESTABLISHED: Ponce Soil Survey Area, Puerto Rico; 1971. The name is from El Tuque community, nearby where it was originally recognized.

REMARKS:
Diagnostic horizons and features recognized in this pedon:
1. Mollic epipedon - the zone from 0 to 13 cm (0 to 5 inches; A horizon).
2. Cambic horizon - the zone from 13 to 28 cm (5 to 11 inches; Bw horizon).
3. Petrocalcic horizon - the zone from 28 to 48 cm (11 to 19 inches; Bkm horizon).
The classification was updated with the 09/2002 draft from Clayey-skeletal, carbonatic, isohyperthermic Lithic Petrocalcic Calciustolls to Clayey, carbonatic, isohyperthermic Calcic Lithic Petrocalcids. In 05/2020 to Clayey, carbonatic, isohyperthermic, shallow Ustic Petrocalcids

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National Cooperative Soil Survey
U.S.A.