LOCATION PARGUERA PREstablished Series
TAXONOMIC CLASS: Clayey-skeletal, carbonatic, isohyperthermic Typic Calciargids
TYPICAL PEDON: Parguera clay--hayland (Colors are for moist soil).
Ap--0 to 7 inches; dark brown (10YR 3/3) clay; strong medium granular structure; slightly hard, friable; slightly sticky, slightly plastic; many very fine and fine roots, common medium roots; many very fine and common fine interstitial pores; about 2 percent, by volume, pebbles; strongly effervescent; slightly alkaline; clear wavy boundary. (5 to 10 inches thick)
Bt--7 to 22 inches; dark yellowish brown (10YR 3/4) clay; strong medium angular blocky structure; slightly hard, firm; moderately sticky, moderately plastic; common fine and medium roots; about 2 percent, by volume, pebbles; strongly effervescent; moderately alkaline; abrupt wavy boundary. (4 to 6 inches thick)
2Btk--22 to 39 inches; dark yellowish brown (10YR 4/6) extremely gravelly clay; moderate medium subangular blocky structure; slightly hard, friable; slightly sticky, slightly plastic; many very fine, fine, and medium roots; many very fine and fine tubular and vesicular pores; common filaments of calcium carbonate; about 80 percent, by volume, pebbles; prominent secondary coating of calcium carbonate on pebbles; violently effervescent; moderately alkaline; clear wavy boundary. (5 to 20 inches thick)
2BCk--39 to 57 inches; dark yellowish brown (10YR 4/6) extremely gravelly coarse sandy loam; weak medium subangular blocky structure; slightly hard, very friable; slightly sticky, slightly plastic; many very fine to medium roots; many very fine, fine, and medium tubular and vesicular pores; few distinct pink (7.5YR 8/4) soft masses and filaments of calcium carbonate; about 75 percent, by volume, pebbles; about 1 percent, by volume, cobbles; prominent secondary coating of calcium carbonate on pebbles and cobbles; violently effervescent; strongly alkaline; abrupt smooth boundary.
3C1--57 to 71 inches; strong brown (7.5YR 4/6) clay; massive; slightly hard, firm; moderately sticky, moderately plastic; few fine roots; common very fine tubular and vesicular pores; many prominent pink (7.5YR 8/4) soft masses of calcium carbonate; about 2 percent, by volume, pebbles; strongly effervescent; moderately alkaline; clear wavy boundary.
3C2--71 to 80 inches; strong brown (7.5YR 4/6) clay; massive; slightly hard, firm; moderately sticky, moderately plastic; few very fine roots; common very fine and fine tubular and vesicular pores; few prominent pink (7.5YR 8/4) soft masses of calcium carbonate; about 2 percent, by volume, pebbles; strongly effervescent; moderately alkaline.
TYPE LOCATION: Lajas, Puerto Rico. Approximately 1.9 miles west from the intersection of P.R. Hwy. 304 and P.R. Hwy. 324, about 1.5 miles west of the La Parguera community, and about 20 feet east of dirt road in a hayfield. USGS Parguera topographic quadrangle (1966); lat. 17 degrees 58 minutes 42 seconds N.; long. 67 degrees 04 minutes 17 seconds W.
RANGE IN CHARACTERISTICS: Solum thickness range from 40 to 60 inches. Reaction ranges from slightly alkaline to strongly alkaline throughout.
The A or Ap horizon has hue of 5YR to 10YR, value of 3 or 4, and chroma of 2 to 4. Content of pebbles is less than 5 percent, by volume. Texture is clay loam or clay in the fine-earth fraction.
The Bt horizon has hue of 2.5YR to 10YR, value of 3 or 4, and chroma of 2 to 6. Content of pebbles is less than 5 percent, by volume. Texture is clay loam or clay in the fine-earth fraction.
The Btk horizon has hue of 7.5YR or 10YR, value of 4 to 6, and chroma of 3 to 6. Filaments and soft masses of calcium carbonate range from common to many. Content of pebbles range from 15 to 60 percent, by volume. Texture clay loam or clay in the fine-earth fraction.
The BCk horizon, where present, has hue of 7.5YR or 10YR, value of 4 to 6, and chroma of 2 or 6. Filaments and soft masses of calcium carbonate range from common to many. Content of pebbles and cobbles range from 35 to 75 percent, by volume. Texture is coarse sandy loam, sandy loam, or sandy clay loam in the fine-earth fraction.
The C horizon has hue of 5YR or 7.5YR, value of 4 or 6, and chroma of 4 to 8. Filaments and soft masses of calcium carbonate range from few to many. Content of pebbles and cobbles range from 0 to 5 percent, by volume. Texture is clay loam or clay in the fine-earth fraction.
COMPETING SERIES: These are no known series in the same family.
GEOGRAPHIC SETTING: Parguera soils are on toe slopes and alluvial fans of the Semiarid Mountains and Valleys MLRA. The climate is semiarid tropical. They formed in clayey and loamy alluvium derived from limestone. Slopes range from 0 to 5 percent. The average annual temperature ranges from 78 to 72 degrees F., and the average annual precipitation ranges from 15 to 38 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Esteli (T) and Guayacan (T) series. Esteli soils are on adjacent higher positions and have a coarse-loamy control sections. Guayacan soils are on similar to higher positions, have fine-loamy control sections, and have a mixed mineralogy.
DRAINAGE AND PERMEABILITY: Moderately Well drained; moderate permeability.
USE AND VEGETATION: Most areas of Parguera soils are used for grazing. The vegetation consists of buffelgrass and huracan grass.
DISTRIBUTION AND EXTENT: Toe slopes and alluvial fans of Semiarid Mountains and Valleys MLRA of Southern Puerto Rico. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina.
SERIES ESTABLISHED: Lajas Municipality, Puerto Rico; 2008. The name is from the La Parguera community where it was originally recognized.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - the zone from 0 to 7 inches (Ap horizon).
Argillic horizon - the zone from 7 to 39 inches (Bt, Btk, and BCk horizons).
Calcic horizon - the zone from 22 to 57 inches (Btk and BCk horizons).
These soils were formerly included in the gravelly clay substratum variant of the Fraternidad series. A soil moisture study conducted in the San Germn Soil Survey Update recognized the Aridic Soil Moisture Regime in Southern Puerto Rico.
ADDITIONAL DATA: Lajas Municipality, Puerto Rico; S97PR-079-004. Sample by NSSL, Lincoln, NE., 06/1997.
Parguera soils are in MLRA 271.