LOCATION TOCOI FLEstablished Series
TAXONOMIC CLASS: Sandy, siliceous, hyperthermic Ultic Alaquods
TYPICAL PEDON: Tocoi fine sand - improved pasture. (Colors are for moist soil.)
A--0 to 13 inches; black (10YR 2/1) fine sand; weak medium granular structure; very friable; many fine and medium roots; many uncoated gray (10YR 6/1) sand grains; very strongly acid; gradual smooth boundary. (4 to 14 inches thick)
Bh1--13 to 20 inches; very dark brown (10YR 2/2) fine sand; moderate medium subangular blocky structure; friable; few fine and medium roots; sand grains are coated with organic matter; strongly acid; gradual smooth boundary.
Bh2--20 to 23 inches; dark reddish brown (5YR 2/2) fine sand; moderate medium granular structure; friable; few pockets of dark brown (10YR 3/3) sand grains having less organic matter than the matrix; strongly acid; gradual smooth boundary. (Combined thickness of the Bh horizons range from 7 to 27 inches)
Bw--23 to 40 inches; brown (10YR 4/3) fine sand; weak fine granular structure; friable; few fine and medium roots; common coarse dark brown (10YR 3/3), very dark gray (10YR 3/1), and very dark brown (10YR 2/2) Bh bodies having more organic matter than the matrix; very strongly acid; clear irregular boundary. (4 to 7 inches thick)
E--40 to 45 inches; light brownish gray (10YR 6/2) fine sand; single grained; loose; strongly acid; gradual wavy boundary. (5 to 25 inches thick)
Btg--45 to 76 inches; light brownish gray (10YR 6/2) loamy fine sand; weak medium subangular blocky structure; sand grains are lightly coated and bridged with clay; common coarse distinct dark gray (10YR 4/1) areas having more organic matter than the matrix and gray (5Y 6/1) areas of depletions; very strongly acid; gradual wavy boundary. (4 to 35 inches thick)
Cg--76 to 80 inches; gray (5Y 6/1) loamy fine sand; weak medium granular structure; friable; common coarse distinct dark grayish brown (10YR 4/2) masses having more organic matter than the matrix; strongly acid.
TYPE LOCATION: St. Johns County, Florida; approximately 0.6 mile southeast of intersection of State Road 16 and Francis Road, and about 400 feet south of State Road 16. SE 1/4, NW 1/4 of Sec. 26, T. 6 S., R. 28 E.
RANGE IN CHARACTERISTICS: Solum thickness is 60 inches or more. Depth to the Btg horizon is more than 40 inches. Soil reaction ranges from extremely acid to strongly acid throughout, except where limed.
The A or Ap horizon has hue of 10YR, value of 2 or 3, and chroma of 1 or 2; or it is neutral with value of 2 or 3. Texture is sand or fine sand.
The Bh horizon has hue of 5YR to 10YR, value of 2 or 3, and chroma 1 to 4; or it is neutral with value of 2. Texture is sand, fine sand, or loamy fine sand.
The Bw horizon has hue of 7.5YR or 10YR, value of 4, and chroma of 2 to 4. Fragments of spodic material range from few to many. Texture is sand or fine sand.
The E horizon has hue of 10YR, value of 5 or 7, and chroma of 2 to 4. Redoximorphic features in shades of gray, yellow, or brown range from none to common. Texture is sand or fine sand.
The Btg horizon has hue of 7.5YR to 5Y, value of 5 to 7, and chroma of 1 or 2. Redoximorphic features in shades of gray, brown, yellow, or red range from none to common. Clay content ranges from 8 to 13 percent. Texture is loamy sand or loamy fine sand.
The Cg horizon, where present, has hue of 10YR to 5Y, value of 5 to 7, and chroma of 1 or 2. Redoximorphic features in shades of brown range from none to common. Texture is sand, fine sand, loamy sand, or loamy fine sand.
COMPETING SERIES: These include the Delks, Monteocha, Pomona, Susanna, Tantile, and Wauchula series. Delks, Pomona, Susanna, Tantile, and Wauchula soils are on similar positions. In addition, Delks soils have an E horizon above the Bh horizon, the poorly and very poorly drained Pomona soils have an E horizon above the Bh horizon and lack an umbric epipedon, Susanna and Tantile soils have an E horizon above the Bh horizon and have orstein, while Wauchula soils lack umbric epipedons and have argillic horizons at depths of less than 40 inches from the surface. The very poorly drained Monteocha soils are in lower positions, have E horizons above the Bh horizon, and have greater than 15 percent clay in the argillic horizon.
GEOGRAPHIC SETTING: Tocoi soils are on broad flats in the lower Coastal Plain. They formed in thick beds of sandy marine sediments. The climate is humid semitropical. Slopes are less than 2 percent. The average annual temperature ranges from 71 to 74 degrees F., and the average annual precipitation ranges from 51 to 61 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing Pomona series, and the Myakka, Ona, St. Johns, Sparr, and Tomoka series. Myakka, Ona, and St. Johns are on similar to lower positions, and lack argillic horizons. In addition, Myakka and St. Johns soils have E horizons above the Bh horizon. The somewhat poorly drained Sparr soils are on higher positions and lack spodic horizons. The very poorly drained Tomoka soils are in lower adjacent positions and are Histosols.
DRAINAGE AND PERMEABILITY: Poorly drained; moderately rapid permeability.
USE AND VEGETATION: Tocoi soils are used mainly for woodland. Some areas have been cleared and used for improved pasture or growing vegetables. Native vegetation consists of slash pine, longleaf pine, waxmyrtle, sawpalmetto, greenbrier, inkberry, bluestems, and pineland threeawn.
DISTRIBUTION AND EXTENT: The Atlantic Coastal Plain in northeast Florida. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Auburn, Alabama.
SERIES ESTABLISHED: St. Johns County, Florida; 1981.
REMARKS: These soils were formerly mapped as a variant of the Olustee series.
The water table is at depths of less than 10 inches for 4 to 8 months during periods of high rainfall and within depths of 20 to 40 inches for 4 to 6 months or more during most years.
Diagnostic features and horizons in this pedon:
Umbric epipedon - the zone from 0 to 23 inches. (A, Bh1, and Bh2 horizons)
Spodic horizon - the zone from 13 to 23 inches. (Bh1 and Bh2 horizons)
Argillic horizon - the zone from 45 to 76 inches. (Btg horizon)