LOCATION CIDRAL PREstablished Series
TAXONOMIC CLASS: Fine, mixed, semiactive, isohyperthermic Typic Paleudults
TYPICAL PEDON: Cidral clay - sugarcane
(Colors are for moist soil)
Ap--0 to 8 inches, dark yellowish brown (10YR 4/4) clay; weak medium subangular blocky structure; firm, slightly sticky, plastic; few fine roots; slight earthworm activity; very strongly acid; abrupt smooth boundary. 6 to 10 inches thick.
B21t--8 to 15 inches, mixed colors, yellowish brown (10YR 5/6), red (2.5YR 4/6) clay with coatings on ped surfaces of dark yellowish brown (10YR 4/4), crushed color strong brown (7.5YR 5/6); moderate medium subangular blocky structure; firm, extremely acid; gradual smooth boundary. 4 to 8 inches thick.
B22t--15 to 21 inches; mixed colors, red (2.5YR 4/6) yellowish brown (10YR 5/6, 5/4) crushed color yellowish red (5YR 5/6) clay; moderate fine and medium subangular blocky structure; firm, slightly sticky, plastic; common patchy clay film; few fine roots; extremely acid; clear wavy boundary. (6 to 8 inches thick)
B23t--21 to 29 inches, Mixed colors, red (2.5YR 4/6) brownish yellow (10YR 6/6) light yellowish brown (10YR 6/4) and few fine faint light gray (10YR 7/1) mottles; crushed color strong brown (7.5YR 5/8) clay, moderate fine and medium subangular blocky structure; slightly sticky, plastic; common patchy clay films, few fine roots; extremely acid; clear wavy boundary. (6 to 10 inches thick)
B31--29 to 40 inches, brownish yellow (10YR 6/8) clay with few fine prominent red (2.5YR 5/6) mottles; weak medium subangular blocky structure; friable, slightly sticky, plastic; few thin patchy clay films; few fine roots; extremely acid; clear smooth boundary. 6 to 12 inches thick.
B32--40 to 75 inches plus, yellow (10YR 7/8) clay loam with few fine faint yellowish red (5YR 5/6), and common fine distinct strong brown (7.5YR 5/6) mottles; weak coarse subangular blocky structure; friable, slightly sticky, plastic; thin patchy clay films; extremely acid.
TYPE LOCATION: Culebrinas SCD, Puerto Rico; 4 miles west of the town of Lares; 150 meters north of kilometer marker 31.9 of Highway 111.
RANGE IN CHARACTERISTICS: Thickness of the solum is over 60 inches and the argillic horizon is over 50 inches. The soils are extremely acid; slightly sticky and plastic throughout.
The colors of the A horizons vary in hues from 7.5YR to 10YR, in values of 4 and chroma from 4 to 6.
Colors of the B2t horizons are mixed and range in hues from 10YR, 7.5YR and 2.5YR, in values and chroma of 4, 5, and 6. In the lower B horizons yellow colors are dominant mostly in chroma of 6 or higher. Texture of the A and B2t horizons is dominantly clay.
The B3 horizon varies in texture from clay loam to clay. Structure of the B2t horizons ranges from moderate fine to medium subangular blocky. Base saturation at 50 inches below the top of the argillic horizon is less than 35 percent (by sum of cations). Organic matter content in the upper 6 inches of the argillic horizon is less than 1.5 percent.
COMPETING SERIES: These are the Cabo Rojo, Maleze, and Bajucos series in the same subgroup and the Rio Lajas, Jobos, Guanajibo and Guerrero series in the same Great Group. The Cabo Rojo soils have darker colored horizons on values darker than 4. The Maleza and Bejucos soils have oxidic mineralogy, in addition, the Bejucos soils are yellower and have more oxides of iron and aluminum in their profiles. The Rio Lajas soils have coarser textured profiles and sandy surface horizons more than 20 inches thick. The Jobos, Guanajibo and Guerrero soils have more than 5 percent nonindurated plinthite in their profiles. The Guerrero soils have sandy surface horizons more than 20 inches thick.
GEOGRAPHIC SETTING: The Cidral soils occur in gently to moderately sloping small valleys between the limestone hills with slope gradients from 2 to 12 percent. The regolith consists of fine textured sediments of variegated colors derived from limestone and volcanic rocks. The climate is humid tropical. The average annual precipitation is 90 inches and the mean annual temperature is 77 degrees F. The mean annual soil temperature at 20 inches is more than 71.6 degrees F. and the difference between mean summer and winter temperature is less than 9 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Moca, Parchas, Colinas and Juncal series. The Moca soils are darker, moderately well drained, and are underlain by expanding clays. The Parchas soils are poorly drained. The Colinas soils are darker, calcareous, and do not have the weathered B horizons. The Juncal series have darker surface horizons, mildly alkaline B horizons and calcareous substrata.
DRAINAGE AND PERMEABILITY: Well drained, medium to slow runoff and moderate permeability.
USE AND VEGETATION: Most of the acreage is planted to sugarcane. Small areas are in native pasture.
DISTRIBUTION AND EXTENT: Humid uplands of Puerto Rico. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina
SERIES ESTABLISHED: Culebrinas SCD, Puerto Rico.
REMARKS: This soil was formerly mapped in the Coto series, but differs from it in being more acid and redder.