LOCATION LEONARDTOWN MDEstablished Series
MLRA(s): 149A (Northern Coastal Plain), 153C (Mid-Atlantic Coastal Plain)
Depth Class: Very deep to bedrock, shallow to moderately deep to root restricting fragipan
Drainage Class (Agricultural): Poorly drained
Saturated Hydraulic Conductivity: Moderately low to low
Landscape: Coastal Plain, upland
Parent Material: Silty eolian deposits over loamy fluviomarine deposits
Slope: 0 to 8 percent
Mean Annual Air Temperature (type location): 13 degrees C. (55 degrees F.)
Mean Annual Precipitation (type location): 1067mm (42 inches)
TAXONOMIC CLASS: Fine-silty, mixed, active, mesic Typic Fragiaquults
TYPICAL PEDON: Leonardtown silt loam in a forested area (Colors are for moist soil)
Oi--0 to 2.5 cm (0 to 1 inch); very dark brown (7.5YR 2.5/2) slightly decomposed leaves and twigs; clear smooth boundary. (0 to 8 cm thick)
Ag--2.5 to 5 cm (1 to 2 inches); black (10YR 2/1) silt loam; weak medium subangular blocky structure; slightly hard, friable; slightly sticky, slightly plastic; many very coarse, coarse, medium and fine roots; extremely acid; clear smooth boundary. (2.5 to 18 cm thick)
Btg1--5 to 36 cm (2 to 14 inches); gray (10YR 5/1) silty clay loam; weak coarse subangular blocky structure; slightly hard, friable; slightly sticky, slightly plastic; common coarse, medium and fine roots; few medium tubular pores; common medium prominent yellowish red (5YR 4/6) iron masses in matrix; common distinct gray (2.5Y 6/1) clay films on faces of peds and in pores; extremely acid; abrupt smooth boundary.
Btg2--36 to 46 cm (14 to 18 inches); gray (2.5Y 6/1) silt loam; moderate coarse subangular blocky structure; slightly hard, friable; slightly sticky, slightly plastic; common medium and fine roots; few medium tubular pores; many medium prominent brownish yellow (10YR 6/8) iron masses in matrix; common distinct gray (2.5Y 6/1) clay films on faces of peds and in pores; extremely acid; clear smooth boundary.
Btg3--46 to 56 cm (18 to 22 inches); light gray (2.5Y 7/1) silt loam; weak coarse subangular blocky structure; slightly hard, friable; slightly sticky, slightly plastic; few medium, fine, and very fine roots; few medium tubular pores; few medium prominent brownish yellow (10YR 6/8) iron masses in matrix; common distinct white (10YR 8/1) clay depletions on faces of peds and in pores; extremely acid; abrupt smooth boundary. (Combined thickness of the Btg horizon is 30 to 64 cm)
Btgx1--56 to 71 cm (22 to 28 inches); gray (10YR 6/1) loam; strong very coarse prismatic structure parting to strong coarse subangular blocky and thick platy; very hard, very firm and brittle in 60 percent of the volume; moderately sticky, moderately plastic; few medium, fine and very fine roots between faces of prisms; common very fine, fine, and medium tubular and vesicular pores throughout; common medium prominent light olive brown (2.5Y 5/6) iron masses in the matrix; common distinct gray (10YR 5/1) clay films on faces of peds and in pores; common fine distinct white (2.5Y 8/1) clay depletions on faces of prisms; extremely acid; abrupt smooth boundary.
Btgx2--71 to 109 cm (28 to 43 inches); gray (10YR 6/1) loam; weak very coarse prismatic structure parting to weak coarse subangular blocky and thick platy; very hard, very firm and brittle in 60 percent of the volume; moderately sticky, moderately plastic; few fine and very fine roots between faces of prisms; common very fine and fine tubular and vesicular pores throughout; common medium prominent strong brown (7.5YR 4/6) iron masses in the matrix; common distinct gray (10YR 5/1) clay films on faces of prisms, and common fine distinct white (10YR 8/1) clay depletions on faces of prisms; extremely acid; abrupt smooth boundary. (Combined thickness of the Btgx horizon is 18 to 53 cm)
2BCg--109 to 157 cm (43 to 62 inches); gray (10YR 5/1) sandy clay loam; moderate very coarse subangular blocky structure; slightly hard, firm and brittle in 5 percent of the volume; moderately sticky, moderately plastic; common very fine, fine, and medium tubular and vesicular pores throughout; common medium prominent strong brown (7.5YR 4/6) iron masses in the matrix; and common fine prominent white (2.5Y 8/1) clay depletions on faces of peds; 1 percent gravel; extremely acid.
TYPE LOCATION: Prince Georges County, Maryland; about 1.02 miles east of Brandywine post office along Brandywine Road (State route 381), 509 feet west of the intersection of Brandywine Road (State Route 381) and Keys Road, and 520 feet south into woods off Brandywine Road (State Route 381). USGS Brandywine, Maryland topographic quadrangle; latitude 38 degrees 41 minutes 32.3 seconds N, and longitude 76 degrees 49 minutes 52.6 seconds W, NAD 83.
RANGE IN CHARACTERISTICS:
Depth to the top of the Argillic horizon: 5 to 30 cm (2 to 12 inches)
Depth to the base of the Argillic horizon: 56 to 140 cm (22 to 55 inches)
Depth to the top of the Fragipan: 50 to 89 cm (20 to 35 inches)
Depth to the base of the Fragipan: 69 to 142 cm (27 to 56 inches)
Solum Thickness: 86 to 183 cm (34 to 72 inches) or more
Depth to Bedrock: Greater than 183 cm (72 inches)
Depth to Seasonal High Water Table: 0 to 30 cm (0 to 12 inches), November to March
Depth to Lithologic Discontinuity: 102 cm (40 inches) or more
Rock Fragment content: 0 to 10 percent rounded mixed gravel in the solum and 0 to 20 percent in the substratum
Soil Reaction: strongly acid to extremely acid, except where limed
RANGE OF INDIVIDUAL HORIZONS:
A horizon:
Color--hue of 10YR to 5Y, value of 2 to 4, and chroma of 1 or 2 or is neutral with value of 3 to 6
Texture (fine-earth fraction)--silt loam, loam, or fine sandy loam high in silt
Redoximorphic features (if they occur)--iron masses in shade of red, yellow,
or brown and iron depletions in shades of brown, yellow, olive, or gray
E horizon (if it occurs):
Color--hue of 10YR to 5Y, value of 4 or 6, and chroma of 1 to 3
Texture (fine-earth fraction)--fine sandy loam, loam, or silt loam
Redoximorphic features (if they occur)--iron masses in shade of red, yellow,
or brown or iron depletions in shades of brown, yellow, olive gray or white
Btg horizon:
Color--hue of 10YR to 5Y, value of 5 to 7, and chroma of 1 or 2.
Texture (fine-earth fraction)--loam, silt loam, or silty clay loam
Redoximorphic features (if they occur)--iron masses in shade of red, yellow,
or brown or iron depletions in shades of brown, yellow, olive gray or white
Btgx, horizon:
Color--hue of 10YR to 5Y, value of 4 to 6, and chroma of 0 to 2
Texture (fine-earth fraction)--loam, silt loam, or silty clay loam
Redoximorphic features (if they occur)--iron masses in shade of red, yellow,
or brown iron depletions in shades of brown, yellow, olive gray or white
BCg or Cg horizon (if it occurs):
Color--hue of 10YR or 2.5Y, value of 4 to 8, and chroma of 1 or 2, or it is variegated with no dominant color
Texture (fine-earth fraction)--loam, silt loam, silty clay loam, or clay loam
Redoximorphic features--iron masses in shade of red, yellow,
or brown and iron depletions in shades of brown, yellow, olive, gray, or white
2BCg or 2Cg horizon (if it occurs):
Color--hue of 2.5Y, 5Y, or 5GY, value of 4 to 6, and chroma of 1 or 2, or is neutral with value of 4 to 8
Texture (fine-earth fraction)--sandy loam, fine sandy loam, or sandy clay loam
Redoximorphic features--iron masses in shade of red, yellow,
or brown; and iron depletions in shades of brown, yellow, olive, gray, or white
COMPETING SERIES:
Mullins soils--have thicker sola
GEOGRAPHIC SETTING:
Landscape: Coastal Plain, upland
Landform: Flats, depressions, ephemeral drainageways on broad interstream divides
Geomorphic Component: Interfluves
Parent Material: Silty eolian deposits over loamy fluviomarine deposits
Slope: 0 to 8 percent
Elevation: 14 to 116 meters (45 to 380 feet)
Frost-free period: 180 to 210 days
Mean Annual Air Temperature: 11 to 14 degrees C. (52 to 57 degrees F.)
Mean Annual Precipitation: 1016 to 1270 mm (40 to 50 inches)
GEOGRAPHICALLY ASSOCIATED SOILS:
Aquasco soils--are somewhat poorly drained
Beltsville soils--are moderately well drained
Butlertown soils--are moderately well drained
Chillum soils--are well drained, do not contain a fragipan
Elkton soils--on similar landscapes, do not contain a fragipan
Fallsington soil--on similar landscapes, contain more sand, do not contain a fragipan
Matapeake soils--are well drained, do not contain a fragipan
Mattapex soils--are moderately well drained, do not contain a fragipan
Othello soils--are poorly drained, do not contain a fragipan
Woodstown soils--are moderately well drained on slightly higher landscapes, do not contain a fragipan
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage Class (Agricultural): Poorly drained
Internal Free Water Occurrence: Thin (50 to 89 cm) and very shallow (less than 25 cm ); common (present 3 to 6 months)
Flooding Frequency and Duration Classes: None
Ponding Frequency and Duration Classes: Occasional or frequent, and very long
Index Surface Runoff Class: High to very high
Saturated Hydraulic Conductivity Class: Moderately low to low
Permeability Class (obsolete): Slow or very slow
Shrink-swell Potential Class: Low
USE AND VEGETATION:
Major Uses: A few areas are used for crop, pasture and non-farm developments, many areas are idle or wooded.
Dominant Vegetation: Where cultivated--hay and pasture, if drained corn, soybeans, and truck crops. Where wooded--wetland hardwoods dominated by sweet gum, and red maple, with some pond pine and an understory of holly, blueberries, huckleberry, azalea, greenbrier, and mountain laurel.
DISTRIBUTION AND EXTENT:
Distribution: Maryland Extent: Moderate
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: St. Marys County, Maryland, 1900.
REMARKS: Prior to 1939, the Leonardtown series included moderately well drained soils that are now correlated to the Beltsville series, and somewhat poorly drained soils that are now correlated to the Aquasco series.
Diagnostic horizons and soil characteristics recognized in this pedon are:
Ochric epipedon--the zone from 0 to 5 cm (0 to 2 inches) (Ag horizon)
Argillic horizon--the zone from 5 to 109 cm (2 to 43 inches) (Btg horizons)
Fragipan--the zone from 56 to 109 cm (22 to 43 inches) (Btgx horizon)
Aquic conditions--redoximorphic features occur in all horizons below the mineral soil surface, with periodic saturation and reduction at some time during the year
Other soil features identified with this pedon:
Series control section--the zone from 0 to 150 cm (0 to 59 inches)
Previous revisions: 03/2006-WDC, 08/2006-WDC/Rev. DRPV
The 2007 revision moves the Typical Pedon. The previous Typical Pedon was imprecisely located and could not be found for study. It also changes the CE activity Class from semiactive to active based on the classification of similar soils in the region.
ADDITIONAL DATA: This pedon sampled as S01 MD 033-002. Additional reference samples S01 MD 033-001, S01 MD 033003. Analysis of all pedons provided by the University of Maryland soil lab.