LOCATION COTO PREstablished Series
TAXONOMIC CLASS: Very-fine, kaolinitic, isohyperthermic Typic Eutrustox
TYPICAL PEDON: Coto clay--Native pasture. (Colors are for moist soil.)
Ap--0 to 9 inches; dark brown (7.5YR 4/4) clay; moderate fine subangular blocky structure; hard, firm, slightly sticky, slightly plastic; many fine roots; strongly acid; clear smooth boundary. (7 to 11 inches thick)
Bo1--9 to 14 inches; reddish brown (5YR 4/4) clay; moderate fine and medium subangular blocky structure; firm, slightly sticky, slightly plastic; thin discontinous clay films; common fine roots; few fine black nodules; very strongly acid; gradual smooth boundary. (4 to 7 inches thick)
Bo2--14 to 19 inches; yellowish red (5YR 4/8) clay; weak medium subangular blocky structure; friable, slightly sticky, slightly plastic; few thin patchy clay films; few fine roots; few fine black nodules; common fine pores; very strongly acid; gradual smooth boundary. (4 to 7 inches thick)
Bo3--19 to 26 inches; strong brown (7.5YR 5/8) clay; weak medium subangular blocky structure; friable, slightly sticky, slightly plastic; few thin patchy clay films; few fine roots; many fine pores; few fine black nodules; strongly acid; gradual smooth boundary. (6 to 9 inches thick)
Bo4--26 to 37 inches; strong brown (7.5YR 5/8) clay; weak medium and coarse subangular blocky structure; friable, slightly sticky, slightly plastic, thin patchy clay films; few fine roots; common fine pores; few fine quartz grains; few fine black nodules; strongly acid; gradual smooth boundary. (9 to 13 inches thick)
Bo5--37 to 49 inches; strong brown (7.5YR 5/8) clay with few fine distinct red (7.5R 4/8) mottles; weak medium and coarse subangular blocky structure; friable, slightly sticky, slightly plastic; few thin clay films; many sand sized quartz grains; strongly acid; gradual smooth boundary. (10 to 14 inches thick)
Bo6--49 to 70 inches; strong brown (7.5YR 5/8) clay with common fine and medium distinct red (7.5R 4/8) mottles; weak medium and coarse subangular blocky structure; friable, slightly sticky, slightly plastic; few thin patchy films; many sand sized quartz grains; strongly acid; gradual smooth boundary. (15 to 25 inches thick)
Bo7--70 to 92 inches; strong brown (7.5YR 5/8) clay with common medium distinct red (7.5R 4/8) mottles; massive; friable, slightly sticky, slightly plastic; very strongly acid.
TYPE LOCATION: Noroeste SCD, Puerto Rico; 11 kilometers east from town of Aguadilla; 6 kilometers southwest of town of Isabela; 200 feet south of kilometer marker 120 on Highway 2. Areial Photograph GS-LR 5-94.
RANGE IN CHARACTERISTICS: Thickness of the solum and depth to the hard limestone is over 40 inches. Consistence is slightly sticky and slightly plastic in the Bo horizons. Reaction is strongly or very strongly acid in the whole profile. Bases plus aluminum meq/100 grams of clay range from 2.7 to 4.7 in the oxic horizon. CEC, by Nh4OAC, ranges from 7 to 15.0 meq/100 grams of clay in the oxic horizon. Base saturation by NH4OAC, in the upper part of the oxic horizon ranges from 20 to 34 percent. Some part of the oxic horizon has thin patchy films or reflective ped surfaces with pressure induced clay orientation. The mean annual soil temperature is 76 degrees F.
The A horizon has hues of 5YR or 7.5YR and values and chroma of 3 to 4. Texture is clay or sandy clay loam. Structure is weak or moderate, fine or medium subangular blocky.
The upper Bo horizons have hues of 5YR, value of 4 and chroma of 4 to 8. Texture is clay. Structure is weak to moderate, fine or medium subangular blocky. The lower Bo horizons have hues of 7.5YR, values of 4 or 5, and chromas of 6 to 8. Red mottles may or may not be present. Structure of the lower Bo horizon is weak fine to coarse or structureless (erosive).
COMPETING SERIES: There are no other known series in the same family. The Bayamon, Catalina, Cotito, Delicias, Hanamaulu, Kapaa, Kunuweia, Lawai, Makopili, Matanzas, Nipe, Pooku, Puhi, and Rosario series are similar soils in related families. The Bayamon and Delicias soils are more strongly weathered. The Catalina soils are redder, with color in hues of 2.5YR and redder, and have clay mineralogy dominated by oxides of iron. The Cotito, Matanzas, and Puhi soils have base saturation values higher than 35 percent in all parts of the oxic horizon. The Hanamaulu, Lawai and Makopili soils have an umbric surface horizon. The Kapaa and Pooku soils have sheets that contain 30 percent or more gibbsite. The Kunuweia and Nipe soils are extremely weathered and have much lower cation retention values. The Rosario soils have serpentine rock within 40 inches of the surface.
GEOGRAPHIC SETTING: The Coto soils are gently to moderately sloping soils on foot slopes and valleys adjacent to the limestone hills on slope gradients of 2 to 12 percent. They formed in fine textured sediments derived from limestone. The climate is humid tropical. The average annual precipitation is 67 to 70 inches and the mean annual temperature is 77 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Bayamon, Cotito, Matanzas series and the Aceitunas, Almirante, Espinosa, Tanama series. The Tanama soils are shallower to the fragmental limestone and have argillic horizons. The Almirante and Espinosa soils have thick argillic horizons. The Aceitunas soils are redder, acid and have thick argillic horizons.
DRAINAGE AND PERMEABILITY: Well drained, runoff is slow to medium and permeability is moderate.
USE AND VEGETATION: Most of the acreage is in sugarcane. Small acreage is in pasture and food crops.
DISTRIBUTION AND EXTENT: North central and Northwestern coastal plains of Puerto Rico. The series is of moderate extent with about 13,000 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina
SERIES ESTABLISHED: Soil Survey of Puerto Rico, 1942.
REMARKS: The classification was updated with the 4/91 draft from Clayey, kaolinitic, isohyperthermic Tropeptic Haplorthox to Very-fine, kaolinitic, isohyperthermic Typic Hapludox. The previous OSED was dated 11/75.
Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - zone from 0 to 9 inches (Ap horizon)
Oxic horizon - zone from 9 to 92 inches (Bo horizons)
ADDITIONAL DATA: Laboratory data is available for typical pedon. S63PR-6-2.