LOCATION GRESSY MOEstablished Series
TAXONOMIC CLASS: Fine-loamy, siliceous, semiactive, mesic Typic Paleudalfs
TYPICAL PEDON: Gressy silt loam on a 3 percent slope in a fescue pasture at an elevation of 960 feet.
Ap--0 to 7 inches; brown (10YR 4/3) silt loam; moderate medium granular structure; friable; many very fine and fine and few medium and coarse roots throughout; many fine to coarse irregular pores; 1 percent mixed subangular gravel; neutral (pH 6.7); clear smooth boundary. (4 to 9 inches thick)
Bt1--7 to 13 inches; brown (7.5YR 4/4) silt loam; moderate medium subangular blocky structure parting to weak fine subangular blocky; friable; common very fine and fine and few medium and coarse roots throughout; common fine and medium tubular and irregular pores; common distinct brown (7.5YR 4/4) clay films on faces of peds; neutral (pH 6.9); clear smooth boundary.
Bt2--13 to 20 inches; strong brown (7.5YR 4/6) silt loam; weak fine subangular blocky structure; friable; common very fine and fine and few medium roots throughout; common fine and medium irregular and tubular pores; common distinct brown (7.5YR 4/4) clay films on faces of peds; few fine rounded black (N 2/0) soft iron-manganese concretions; 1 percent subangular mixed gravel; neutral (pH 6.9); clear smooth boundary.
Bt3--20 to 31 inches; strong brown (7.5YR 4/6) silt loam; moderate fine subangular blocky structure; firm; few very fine and fine roots throughout; common very fine and fine tubular and few medium vesicular pores; common prominent reddish brown (5YR 4/4) clay films on faces of peds; few distinct light yellowish brown (10YR 6/4) silt coats on faces of peds; few fine rounded black (N 2/0) soft iron-manganese concretions; 10 percent subangular mixed gravel; neutral (pH 6.8); clear wavy boundary. (Combined thickness of the Bt horizon is 8 to 30 inches)
2Bt4--31 to 49 inches; red (2.5YR 4/8) very gravelly clay loam; weak very coarse prismatic structure parting to moderate medium platy and moderate fine subangular; firm; few very fine and fine roots throughout; few prominent reddish brown (5YR 4/4) clay films on faces of peds; few prominent red (2.5YR 4/6) iron stains on faces of peds; 45 percent subangular mixed gravel; moderately acid (pH 5.9); gradual irregular boundary. (7 to 26 inches thick)
3Bt5--49 to 80 inches; red (2.5YR 4/8) gravelly clay; weak medium angular blocky structure parting to moderate fine angular blocky; firm; few very fine vesicular tubular pores; common distinct red (2.5YR 4/6) and few brown (7.5YR 4/4) clay films on faces of peds; 25 percent subangular mixed gravel; strongly acid (pH 5.4). (25 or more inches thick)
TYPE LOCATION: Howell County Missouri; 1 1/2 miles NW of Hurley; 1,200 feet east and 2,100 feet north of the south west corner of section 23, T. 26 N., R. 24 W; Caufield USGS quadrangle, UTM Zone 15, Easting 586160m, Northing 4041380m.
RANGE IN CHARACTERISTICS: Solum thickness is more than 80 inches.
A or Ap horizon
Rock fragments: 0 to 35 percent gravel
Hue: 10YR
Value: 3 to 5
Chroma: 2 or 3
Fine earth: silt loam
Reaction: neutral to very strongly acid
E or EB horizon (where present)
Rock fragments: 0 to 35 percent gravel
Hue: 10YR or 7.5YR
Value: 3 to 5
Chroma: 3 to 6
Fine earth: silt loam, loam
Reaction: neutral to very strongly acid
Bt horizon
Rock fragments: 0 to 35 percent gravel
Hue: 10YR or 7.5YR
Value: 4 or 5
Chroma: 4 or 6
Fine earth: silt loam, loam, silty clay loam
Reaction: neutral to very strongly acid
2Bt horizon
Rock fragments: 0 to 50 percent gravel, 0 to 25 percent cobbles
Hue: 2.5YR to 7.5YR
Value: 4 or 5
Chroma: 4 to 8
Fine earth: loam, silty clay loam, clay loam
Reaction: moderately to very strongly acid
3Bt horizon
Rock fragments: 0 to 35 percent gravel, 0 to 20 percent cobbles
Hue: 10YR to 10R
Value: 4 to 6
Chroma: 6 or 8
Fine earth: silty clay, clay
Reaction: strongly or very strongly acid
COMPETING SERIES: This is the Portia series. Portia soils formed in residuum weathered from sandstone and have more sand thoughout the series control section.
GEOGRAPHIC SETTING: Gressy soils are on ridgetops. Slopes range from 1 to 8 percent. These soils formed in silty and gravelly slope alluvium and the underlying loamy and clayey colluvium and residuum. Elevations are commonly 700 to 1,200 feet. Mean annual temperature ranges from 54 to 58 degrees F., and the mean annual precipitation varies from 40 to 45 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Alred, Gatewood, Mano, Ocie and Viraton soils. Alred, Mano and Ocie soils have a loamy-skeletal over clayey particle-size class and are on side slopes. Gatewood soils are moderately deep to dolomite bedrock and are on side slopes. Viraton soils have a fragipan and are adjacent to Gressy soils on the same ridge top positions.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is low to medium. Permeability is moderate and the saturated hydraulic conductivity is moderately high.
USE AND VEGETATION: These soils are used mainly for pasture and hayland. A few areas are used for cultivated crops. Native vegetation is mixed hardwoods.
DISTRIBUTION AND EXTENT: The Ozark Highland region (MLRA 116A) of southern Missouri and possibly northern Arkansas. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia.
SERIES ESTABLISHED: Texas County, Missouri soil survey; 2002.
REMARKS: Diagnostic horizons and features in this pedon are:
Ochric epipedon - the zone from the surface to a depth of 7 inches (Ap horizon).
Argillic horizon - the zone from 7 to 80 inches - Bt, 2Bt and 3Bt horizons).
This soil is being mapped predominantly in the Jefferson City formation (Ordivician age) in Missouri.
Gressy soils were previously included with the Viraton series in mapping.
University of Missouri Soil Characterization Lab number S96MO09127.