LOCATION WHITSON IL+INEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Typic Endoaqualfs
TYPICAL PEDON: Whitson silt loam, 0 to 2 percent slopes in a cultivated field at an elevation of 564 feet above mean sea level. (All colors are for moist soil unless otherwise noted.)
Ap--0 to 25 cm (0 to 10 inches); dark grayish brown (10YR 4/2) silt loam, light gray (10YR 7/2) dry; weak fine granular structure; friable; many roots; few fine distinct black (7.5YR 2.5/1) iron and manganese oxides accumulations in the matrix; neutral; abrupt smooth boundary. [ 15 to 25 cm (6 to 10 inches) thick]
Eg1--25 to 46 cm (10 to 18 inches); light brownish gray (2.5Y 6/2) silt loam, very pale brown (10YR 8/2) dry; weak fine granular structure; friable; common roots; many fine and medium prominent yellowish brown (10YR 5/6) masses of iron in the matrix; very few prominent black (7.5YR 2.5/1) masses of iron and manganese oxides in the matrix; neutral; clear irregular boundary.
Eg2--46 to 58 cm (18 to 23 inches); light brownish gray (2.5Y 6/2) silt loam; moderate coarse granular structure; friable; common roots; many fine and medium prominent yellowish brown (10YR 5/6) masses of iron in the matrix; few fine prominent black (7.5YR 2.5/1) masses of iron and manganese oxides in the matrix; strongly acid; clear irregular boundary. [Combined thickness of the Eg horizons ranges from 8 to 41 cm (3 to 16 inches)].
Btg1--58 to 76 cm (23 to 30 inches); light brownish gray (2.5Y 6/2) silty clay loam; moderate fine and medium subangular blocky structure; firm; few roots; many distinct light brownish gray (2.5Y 6/2) clay films on faces of peds; many fine and medium prominent yellowish brown (10YR 5/6) masses of iron in the matrix; few fine prominent black (7.5YR 2.5/1) masses of iron and manganese oxides in the matrix; very strongly acid; gradual smooth boundary.
Btg2--76 to 97 cm (30 to 38 inches); light brownish gray (2.5Y 6/2) silty clay loam; moderate coarse prismatic structure parting to moderate coarse subangular blocky; firm; few roots; common prominent and distinct light brownish gray (2.5Y 6/2) clay films on faces of peds; many fine and medium prominent yellowish brown (10YR 5/6) masses of iron in the matrix; very few fine prominent black (7.5YR 2.5/1) masses of iron and manganese oxides in the matrix; very strongly acid; gradual smooth boundary.
Btg3--97 to 112 cm (38 to 44 inches); light brownish gray (2.5Y 6/2) silty clay loam; moderate coarse prismatic structure parting to moderate coarse subangular blocky; firm; few roots; many prominent light brownish gray (2.5Y 6/2) clay films on faces of peds; common fine prominent yellowish brown (10YR 5/6) masses of iron in the matrix; very few fine prominent black (7.5YR 2.5/1) masses of iron and manganese oxides in the matrix; very strongly acid; gradual smooth boundary.
Btg4--112 to 122 cm (44 to 48 inches); light brownish gray (2.5Y 6/2) silty clay loam; weak coarse prismatic structure parting to moderate coarse angular blocky; firm; few roots; many prominent light brownish gray (2.5Y 6/2) clay films on faces of peds; many fine distinct light olive brown (2.5Y 5/4) masses of iron and manganese oxides and common fine prominent yellowish brown (10YR 5/6) masses of iron in the matrix; common fine prominent black (7.5YR 2.5/1) masses of iron and manganese oxides in the matrix; very strongly acid; gradual smooth boundary.
Btg5--122 to 132 cm (48 to 52 inches); light brownish gray (2.5Y 6/2) silty clay loam; weak coarse prismatic structure parting to moderate coarse subangular blocky; firm; few roots; few faint light brownish gray (2.5Y 6/2) clay films on faces of peds; many fine distinct light olive brown (2.5Y 5/4) masses of iron and manganese oxides and common fine prominent yellowish brown (10YR 5/6) masses of iron in the matrix; common medium prominent black (7.5YR 2.5/1) masses of iron and manganese oxides in the matrix; very strongly acid; clear wavy boundary. [(Combined thickness of the Btg horizons ranges from 41 to 81 cm (16 to 32 inches)].
BCg1--132 to 157 cm (52 to 62 inches); light brownish gray (2.5Y 6/2) silt loam; weak coarse prismatic structure parting to strong coarse angular blocky; very firm; few roots; many fine and medium prominent yellowish brown (10YR 5/6) masses of iron in the matrix; many medium and coarse prominent black (7.5YR 2.5/1) masses of iron and manganese oxides in the matrix; very strongly acid; abrupt wavy boundary. [ 13 to 33 cm (5 to 13 inches)]
2BCg2--157 to 180 cm (62 to 71 inches); light brownish gray (2.5Y 6/2) and yellowish brown (10YR 5/4) silt loam; weak coarse prismatic structure; friable; no roots; few very fine pores; few distinct dark brown (7.5YR 3/2) masses of iron and manganese oxides on plates; many medium prominent yellowish brown (10YR 5/6) masses of iron in the matrix; common fine prominent black (7.5YR 2.5/1) masses of iron and manganese oxides in the matrix; few medium prominent strong brown (7.5YR 5/8) masses of iron in the matrix; ; very strongly acid; clear wavy boundary. [ 0 to 25 cm (0 to 10 inches)]
2Cg--180 to 203 cm (71 to 80 inches); light brownish gray (2.5Y 6/2) loam; platy rock structure; friable; many medium prominent yellowish brown (10YR 5/8) and yellowish brown (10YR 5/6) masses of iron in the matrix; few fine prominent strong brown (7.5YR 5/8) masses of iron in the matrix; few fine prominent black (7.5YR 2.5/1) masses of iron and manganese oxides in the matrix; strongly acid.
TYPE LOCATION: Whitson silt loam, 0 to 2 percent slopes at an elevation of 564 feet (172 meters) above MSL; Clark County, Illinois; 256 meters (840 feet) south and 23 meters (75 feet) east of the northwest corner of sec. 14, T. 11 N., R. 11 W.; USGS Dennison, Illinois topographic quadrangle; latitude 39 degrees 24 minutes 6.1 seconds N. and longitude 87 degrees 36 minutes 35.3 seconds W.; UTM Zone 16S 0447493 eastings 4361535 northings; NAD 83.
RANGE IN CHARACTERISTICS: Depth to the top of the argillic ranges from 23 to 61 cm (9 to 24 inches). Depth to the base of the argillic ranges from 89 to 140 cm (35 to 55 inches). Thickness of loess or silty material is more than 140 cm (55 inches). Depth to horizons with more than 7 percent fine sand and coarser is more than 140 cm (55 inches). The particle size control section averages 27 to 35 percent clay, but some horizons may range from 25 to 40 percent clay. Depth to carbonates is more than 152 cm (60 inches).
Ap or A horizon:
Hue 10YR
Value 4 or 5
Chroma 1 or 2
Texture silt loam
Rock fragments none
Reaction strongly acid to neutral
Eg horizon:
Hue 10YR or 2.5Y
Value 5 to 7
Chroma 1 or 2
Texture silt loam
Rock fragments none
Reaction very strongly acid to neutral
Btg horizon:
Hue 10YR, 2.5Y, or 5Y
Value 4 to 6
Chroma 1 or 2; variegated colors may range to 8
Texture silty clay loam
Rock fragments none
Reaction very strongly acid to moderately acid
BCtg or BCg horizon:
Hue 10YR, 2.5Y, 5Y, or neutral
Value 4 to 6
Chroma 0 to 2; variegated colors may range to 8
Texture silty clay loam or silt loam
Rock fragments none
Reaction very strongly acid to slightly acid
2BCtg, 2BCg, or 2Cg horizon:
Hue 10YR, 2.5Y, 5Y, or neutral
Value 4 to 6
Chroma 0 to 2; variegated colors may range to 8
Texture silt loam, loam, or clay loam
Rock fragments 0 to 5 percent
Reaction very strongly acid to slightly alkaline
COMPETING SERIES: Series in the same family include
Moniteau,
Racoon, and
Sebring. Moniteau soils formed in alluvium on floodplains and averages from 5 to 15 percent fine and coarser sand within 55 inches of the surface. Racoon soils have a thick E horizon with the top of the argillic horizon below 24 inches.
Sebring soils have mean annual soil temperature of 47 to 52 degrees F.
GEOGRAPHIC SETTING: Whitson soils generally occur on nearly level to gently sloping till plains. They formed in more than 55 inches of loess typically underlain by pedisediment or Roxanna silts within 80 inches. Mean annual precipitation ranges from 35 to 42 inches; mean annual soil temperature ranges
from 52 to 57 degrees F.; elevation ranges from 400 to 800 feet above MSL; frost free days range from 175 to 195.
GEOGRAPHICALLY ASSOCIATED SOILS: These include Atlas, Blair, Hickory, Menfro, Muren, Newberry, Racoon, and Stoy. The poorly drained Whitson soils belong to a drainage sequence consisting of moderately well drained Hosmer and somewhat poorly drained Stoy soils.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Poorly drained. The potential for surface runoff is negligible to low. Saturated hydraulic conductivity is moderately low to moderately high (0.42 to 1.41 micrometer per second). Permeability is slow. An apparent seasonal high water table is within a depth of 31 cm (1 foot) at some time between January and May in normal years.
USE AND VEGETATION: The soils are used mostly for cultivated crops such as corn, soybeans, and small grains. Some areas are used for hay, pasture, or woodland.
DISTRIBUTION AND EXTENT: In Illinois the known extent is moderate.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Shelby County, Illinois, 1932.
REMARKS: Whitson is re-activated with this update (8/2006). The OSD type location is moved to Clark County, Illinois. The concept of Whitson will remain the same except for the pH ranges to very strongly acid and carbonates are not within a depth of 60 inches.
Diagnostic horizons and features recognized in this pedon are:
ochric epipedon - the zone from the surface of the soil to a depth of 23 inches (0 to 58 cm) (Ap and Eg horizons);
albic horizon - the zone from 10 to 23 inches (25 to 58 cm)(Eg horizons);
argillic horizon - the zone from approximately 23 to 52 inches (58 to 132 cm)(Btg horizons);
aquic conditions - redoximorphic features in all horizons below 10 inches (25 cm);
Representative DMU is 503405. Illinois pedon number 73IL-023-014.