LOCATION MEDOC MO
Established Series
ACP-PRF
09/2012
MEDOC SERIES
The Medoc series consists of very deep, somewhat poorly drained soils that formed in a thin mantle of silty loess over residuum of the Cherokee Prairies (MLRA 112). Medoc soils are on uplands and the slope ranges from 0 to 1 percent. Mean annual precipitation is 40 inches and the mean annual temperature is 57 degrees F.
TAXONOMIC CLASS: Fine, mixed, active, thermic Aeric Albaqualfs
TYPICAL PEDON: Medoc silt loam - on a 0 to 1 percent slope in a fallowed wheat field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 9 inches; dark gray (10YR 4/1) silt loam, light brownish gray (10YR 6/2) dry; weak medium subangular blocky structure; very friable; many fine roots; common fine pores; slightly alkaline; clear smooth boundary. (6 to 10 inches thick)
E--9 to 13 inches; pale red (2.5YR 6/2) silt loam; weak medium subangular blocky structure; very friable; common fine roots; common fine pores; common fine prominent red (2.5YR 4/8) masses of iron accumulation throughout; slightly alkaline; abrupt smooth boundary. (3 to 10 inches thick)
2Btg--13 to 19 inches; dark gray (10YR 4/1) clay; moderate medium prismatic structure parting to strong fine subangular blocky; very firm; common fine roots; few fine pores; many continuous prominent dark gray (10YR 4/1) clay films on faces of peds; common fine prominent red (2.5YR 4/8) masses of iron accumulation throughout; moderately acid; clear smooth boundary. (5 to 12 inches thick)
2Bt1--19 to 24 inches; dark yellowish brown (10YR 4/4) silty clay; weak medium prismatic structure parting to strong fine subangular blocky; very firm; few fine roots; few fine pores, many continuous prominent dark gray (10YR 4/1) and dark yellowish brown (10YR 4/4) clay films on faces of peds; few fine distinct dark gray (10YR 4/1) iron depletions throughout; moderately acid; clear smooth boundary.
2Bt2--24 to 32 inches; yellowish brown (10YR 5/4) silty clay loam; weak medium prismatic structure parting to moderate fine subangular blocky; very firm; few fine roots; common fine pores; common discontinuous distinct yellowish brown (10YR 5/4) clay films on faces of peds; common fine distinct gray (10YR 6/1) iron depletions and few fine prominent strong brown (7.5YR 5/8) masses of iron accumulation throughout; moderately acid; clear smooth boundary. (Combined thickness of the 2Bt horizon is 10 to 24 inches.)
3Btg1--32 to 62 inches; gray (10YR 6/1) silty clay loam; moderate medium prismatic structure parting to moderate medium subangular blocky; firm; few fine roots; common fine and medium pores; common discontinuous distinct gray (10YR 6/1) clay films on ped faces; common medium prominent strong brown (7.5YR 5/8) and few fine distinct yellowish brown (10YR 5/4) masses of iron accumulation throughout; few rounded medium and coarse black concretions; slightly acid; gradual smooth boundary.
3Btg2--62 to 75 inches; gray (10YR 6/1) silty clay loam; moderate medium prismatic structure parting to moderate medium subangular blocky; firm; few fine roots; few fine pores; common distinct gray (10YR 6/1) clay films on ped faces; common discontinous medium prominent strong brown (7.5YR 5/8) and few fine distinct dark yellowish brown (10YR 4/4) masses of iron accumulation throughout; few black stains on ped faces; few rounded medium and coarse black concretions; moderately acid; gradual smooth boundary.
3Btg3--75 to 85 inches; gray (10YR 6/1) silty clay; weak coarse prismatic structure parting to strong fine subangular blocky; extremely firm; few fine roots; few fine pores; common discontinuous prominent gray (10YR 6/1) clay films on vertical ped faces; many coarse distinct yellowish brown (10YR 5/8) masses of iron accumulation throughout; few black stains on vertical faces of peds; moderately acid. (Combined thickness of the 3Btg horizon is 24 inches to several feet.)
TYPE LOCATION: Jasper County, Missouri; about 3 miles north of Asbury; 300 feet south and 1000 feet east of the northwest corner, sec. 32, T. 30 N., R. 33 W.; lat. 37 degrees 19 minutes 10 seconds N, long. 94 degrees 35 minutes 28 seconds W
RANGE IN CHARACTERISTICS:
Soil moisture control section: aquic
Depth to abrupt textural change: 12 to 20 inches
Depth to albic horizon: 6 to 10 inches
Depth to argillic horizon: 12 to 20 inches
Depth to redox concentrations: 6 to 10 inches
Depth to redox depletions: 14 to 32 inches
Depth to episaturation: 12 to 18 inches from February to April
Particle-size control section (weighted average):
Clay content: 35 to 60 percent
Sand content: 6 to 20 percent
A horizon:
Hue: 10YR
Value: 3 or 4 moist and 6 dry
Chroma: 1 to 3
Texture: silt loam
Reaction: 6.6-7.8
E horizon:
Hue: 10YR
Value: 5 or 6
Chroma: 2 or 3
Redoximorphic features: None to common masses of iron accumulation in shades of brown or red
Texture: silt loam
Reaction: 5.1-6.5
2Btg horizon:
Hue: 10YR
Value: 3 to 5
Chroma: 1 to 2
Redoximorphic features: Few to many masses of iron accumulation in shades of brown or red
Texture: clay
Reaction: 4.5-5.5
2Bt horizon:
Hue: 7.5YR or 10YR
Value: 4 or 5
Chroma: 3 to 8
Redoximorphic features: Few to many masses of iron accumulation and depletions in shades of brown, red, or gray
Texture: clay, silty clay or silty clay loam
Reaction: 4.5-5.5
3Bt horizon (where present)
Hue: 10YR
Value: 4 or 5
Chroma: 6 or 8
Redoximorphic features: Few to many masses of iron accumulation in shades of gray or brown, none to few black stains
Texture: silty clay or silty clay loam
Reaction: 5.1-5.5
3Bt\E horizon (where present)
Hue: 10YR
Value: 5
Chroma: 8
Redoximorphic features: Few to common masses of iron accumulation in shades of brown, none to few black stains
Other features: From 15 to 20 percent of this horizon has tongues and interfingers of silt that ranges from 2 to 10 cm wide and extends throughout the horizon; the tongues get wider with depth
Texture: silty clay
Reaction: 5.1-5.5
3Btg horizon:
Hue: 10YR or 2.5Y
Value: 6
Chroma: 1 or 2
Redoximorphic features: Few to many masses of iron accumulation in shades of brown, none to few black stains; none to few rounded black concretions
Other features: in lower part of horizon; from 1 to 15 percent tongues and interfingers of silt are in some pedons
Texture: silty clay or silty clay loam
Reaction: 4.5-5.5
Some pedons are underlain with sand stone or shale bedrock below a depth of 60 inches.
COMPETING SERIES:
Hornsboro soils have more than 10 percent sand in the upper 20 inches of the argillic horizon and commonly have rounded quartz gravel
Springfield soils have a solum that is 30 to 60 inches thick
GEOGRAPHIC SETTING:
Parent material: loess and residuum derived from shale
Landscape: plains
Landform: upland
Slopes: 0 to 1 percent
Mean annual temperature: 56 to 58 degrees F
Mean annual precipitation: 38 to 42 inches
GEOGRAPHICALLY ASSOCIATED SOILS:
Barden soils are on higher landscape positions and lack an abrupt texture change between the A or E and the argillic horizon
Cherokee soils are on lower landscape positions and are gray throughout
Opolis soils are on slightly higher level or nearly level to slightly convex landscape positions, are brown in the upper argillic horizon and are moderately well drained
Parsons soils are on lower landscape positions and are gray throughout
Taloka soils are on lower landscape positions and are gray
DRAINAGE AND PERMEABILITY:
Drainage: somewhat poorly drained
Permeability: slow
Runoff: low
USE AND VEGETATION: Most areas are used for cropland. A few areas are used for native hayland or pasture. Principal crops are wheat, corn, milo, and soybeans. Native vegetation is prairie grasses, mainly big and little bluestem.
DISTRIBUTION AND EXTENT: Southwest Missouri and possibly Southeast Kansas and Northeast Oklahoma. The soils are of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Jasper County, Missouri, 2001. The name is from a small community in the county.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 13 to 33 inches.
(2Btg, 2Bt1, 2Bt2, 2Bt3, 2Bt4, and 3Btg1 horizons)
Ochric epipedon: The zone from the O to 13 inches (Ap and E horizons)
Albic horizon: The zone from 9 to 13 inches. (E horizon)
Argillic horizon: The zone from 13 to 85 inches.
(2Btg, 2Bt, 3Btg)
Redoximorphic concentrations: In the zone from 9 to 19 inches.
(E and 2Btg horizons) and in the zone from 32 to 85
inches (3Btg1, 3Btg2, 3Btg3, and 3Btg4 horizons)
Redoximorphic depletions: In the zone from 19 to 22 inches (2Bt1 horizon) and
the zone from 28 to 32 inches. (2Bt4 horizon)
Episaturation: The zone of saturation at 12 to 18 inches. (E and 2Btg horizons)
Abrupt textural change: At the upper boundary of the 2Btg horizon.
Lithologic discontinuity: At the upper boundary of the 2Btg horizon and the 3Btg horizon.
These soils were formerly included in the Cherokee and Parsons series.
The assignment of the cation-exchange activity class is supported by lab sample(s) numbers 94MO097003 and Missouri Characterization Laboratory Sample Number M9209706
Taxonomic Version: Keys to Soil Taxomony, Eighth Edition, 1998
National Cooperative Soil Survey
U.S.A.