LOCATION SANSDESSEIN MOEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Fluvaquentic Vertic Endoaquolls
TYPICAL PEDON: SansDessein silty clay - on a one percent slope in a cultivated field. (Colors are for moist soil unless otherwise stated.)
Ap1--0 to 8 centimeters (0 to 3 inches); very dark gray (10YR 3/1) silty clay, dark gray (10YR 4/1) dry; moderate fine subangular blocky structure parting to weak fine granular; firm; few very fine and fine roots; common very fine tubular pores; slightly alkaline; abrupt smooth boundary.
Ap2--8 to 20 centimeters (3 to 8 inches); 80% very dark gray (10YR 3/1) and 20% very dark grayish brown (10YR 3/2) silty clay, dark grayish brown (10YR 4/2) dry ; moderate very fine and fine angular blocky structure; very firm; few very fine and fine roots, few very fine tubular pores; slightly alkaline; abrupt smooth boundary.
A--20 to 43 centimeters (8 to 17 inches); very dark gray (10YR 3/1) silty clay, dark grayish brown (10YR 4/2) dry ; moderate fine prismatic structure parting to moderate very fine subangular blocky; very firm; few very fine and fine roots; common very fine tubular pores; common fine prominent dark yellowish brown (10YR 4/6) masses of oxidized iron (fe+3); common faint dark gray (10YR 4/1) iron depletions on faces of peds; neutral; clear smooth boundary. (Combined thickness of A horizons is 25 to 58 centimeters, 10 to 23 inches.)
Bg1--43 to 58 centimeters (17 to 23 inches); dark grayish brown (10YR 4/2) silty clay; moderate fine prismatic structure parting to moderate very fine subangular blocky; very firm; few very fine and fine roots; common very fine tubular pores; common fine prominent dark yellowish brown (10YR 4/6) masses of oxidized iron (fe+3) on surfaces along root channels; many faint dark gray (10YR 4/1) iron depletions on faces of peds; slightly alkaline; clear smooth boundary.
Bg2--58 to 89 centimeters (23 to 35 inches); 70% dark grayish brown (10YR 4/2) and 30% dark gray (10YR 4/1) silty clay; weak fine prismatic structure parting to moderate very fine and fine angular blocky; very firm; common very fine tubular pores; common fine prominent dark yellowish brown (10YR 4/6) masses of oxidized iron (fe+3); slightly alkaline; gradual smooth boundary.
Bg3--89 to 124 centimeters (35 to 49 inches); 70% dark gray (10YR 4/1) and 30% dark grayish brown (10YR 4/2) silty clay; weak fine prismatic structure parting to moderate very fine and fine angular blocky; very firm; common very fine tubular pores; common fine prominent dark yellowish brown (10YR 4/6) and strong brown (7.5YR 4/6) masses of oxidized iron (fe+3); slightly effervescent; slightly alkaline; clear smooth boundary.
Bg4--124 to 142 centimeters (49 to 56 inches); 50% gray (10YR 5/1) and 50% dark grayish brown (2.5Y 4/2) silty clay; moderate very fine and fine subangular blocky structure; firm; common very fine tubular pores; common fine prominent dark yellowish brown (10YR 4/6) and strong brown (7.5YR 4/6) masses of oxidized iron (fe+3); slightly effervescent; moderately alkaline; abrupt smooth boundary. (Combined thickness of Bg horizons is 46 to 127 centimeters, 18 to 50 inches.)
2Cg--142 to 173 centimeters (56 to 68 inches); 40% dark gray (10YR 4/1), 40% dark grayish brown (10YR 4/2), and 20% dark grayish brown (2.5Y 4/2) stratified silt and silt loam; massive; friable; common very fine tubular pores; common fine prominent dark yellowish brown (10YR 4/6) and strong brown (7.5YR 4/6) masses of oxidized iron (fe+3); slightly effervescent; moderately alkaline; abrupt smooth boundary. (Combined thickness of 2Cg horizons is 51 to 99 centimeters, 20 to 39 inches.)
3Cg--173 to 203 centimeters (68 to 80 inches); 50% dark grayish brown (10YR 4/2) and 50% grayish brown (10YR 5/2) stratified fine sand; massive; very friable; few very fine tubular pores; common fine prominent dark yellowish brown (10YR 4/6) and common fine prominent strong brown (7.5YR 4/6) masses of oxidized iron (fe+3); slightly effervescent; moderately alkaline. (Combined thickness of 3Cg horizons is 0 to 48 centimeters, 0 to 19 inches.)
TYPE LOCATION: Warren County, Missouri; located about 292 feet east and 2,306 feet south of the northwest corner of sec. 29, T. 46 N., R. 4 W. of the 5th Principal Meridian; 38091-F4 Hermann, Missouri USGS quadrangle; lat. 38 degrees 43 minutes 16.1 seconds N. and long. 91 degrees 23 minutes 53.4 seconds W.; UTM 639,252 meters easting, 4,287,049 meters northing, Zone 15, NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon: 25 to 58 centimeters (10 to 23 inches) Depth to top of the cambic horizon: 25 to 58 centimeters (10 to 23 inches) Depth to the base of the cambic horizon: 104 to 152 centimeters (41 to 60 inches)
Particle-size control section: averages 35 to 60 percent clay
Solum thickness: 104 to 152 centimeters (41 to 60 inches)
Depth to carbonates: 38 to 203 centimeters (15 to more than 80 inches) Depth to loamy materials: 104 to 152 centimeters (41 to 60 inches)
Ap and A horizons
Hue: 10YR or 2.5Y
Value: 2 or 3, moist; 4 or 5, dry
Chroma: 1 or 2
Texture: silty clay loam, silty clay, or clay
Average clay content: 35 to 60 percent
Average sand content: 1 to 10 percent
Reaction: slightly acid to slightly alkaline
Bg horizons
Hue: 10YR or 2.5Y
Value: commonly 4 to 6, less commonly 3 Chroma: 1 or 2
Texture: commonly silty clay or clay, less commonly silty clay loam
Average clay content: 35 to 60 percent
Average sand content: 1 to 20 percent
Reaction: slightly acid to moderately alkaline
2Bg horizons (where present) Hue: 10YR
Value: 4 or 5
Chroma: 1 to 4 (less than 50 percent 3 or 4)
Texture: silt loam, very fine sandy loam, or loam Average clay content: 5 to 26 percent Average sand content: 5 to 65 percent (50 percent or more very fine sand) Reaction: neutral to moderately alkaline
2Cg horizons
Hue: 10YR or 2.5Y
Value: 4 to 6
Chroma: 1 to 4 (less than 50 percent 3 or 4) Texture: silt, silt loam, or very fine sandy loam
Average clay content: 5 to 26 percent
Average sand content: 10 to 65 percent (50 percent or more very fine sand)
Reaction: neutral to moderately alkaline
3Cg horizons (where present)
Hue: 10YR
Value: 4 or 5
Chroma: 2 to 4 (less than 50 percent 3 or 4)
Texture: fine sand or loamy sand Average clay content: 1 to 5
Average sand content: 80 to 96 percent
Reaction: neutral to moderately alkaline
COMPETING SERIES: These are the Blend, Darwin, Ricco, Saddlerock, Stillwater, and Waldo series. Blend and Saddlerock soils have one or more buried A horizons in the series control section. Saddlerock soils also have a MAP of 10 inches. Darwin soils do not have loamy textures of silt, silt loam, or very fine sandy loam in the series control section. Stillwater soils do not have a cambic horizon and have a MAP of about 5 inches. Waldo soils are more acid than slightly acid in the cambic horizon.
GEOGRAPHIC SETTING: SansDessein soils are on nearly level, linear to concave areas. These soils formed in alluvium and occur on flood plains and flood plain steps of the Missouri River. Slopes are 0 to 2 percent. The mean annual temperature ranges from 10 to 13 degrees C (50 to 55 degrees F), and mean annual precipitation ranges from 889 to 1020 millimeters (35 to 40 inches).
GEOGRAPHICALLY ASSOCIATED SOILS: The somewhat poorly drained Blencoe and Peers soils are on slightly higher areas. The poorly drained Booker soils are on slightly lower areas. The well drained Lowmo soils are on slightly higher areas. Blencoe soils are clayey over loamy with loamy materials within the particle size control section. Booker soils contain more clay in the particle size control section. Lowmo and Peers soils contain less clay in the particle size control section.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Poorly drained. The potential for runoff is high. Permeability is very slow. Saturated hydraulic conductivity (Ksat) is .01-.42 micrometers per second. In undisturbed areas an apparent water table has an upper limit of 0 to 30 centimeters (0 to 12 inches) during November to May in most years. These soils are subject to occasional flooding for long duration due to levee breaks.
USE AND VEGETATION: Most areas are used for growing soybeans and corn. The native vegetation is trees.
DISTRIBUTION AND EXTENT: The Central Mississippi Valley Wooded Slopes, MLRA 115B, of east central Missouri. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Warren County, Missouri, 2009.
REMARKS: These soils were previously mapped Darwin and Waldron soils in Missouri. They differ from Darwin soils by having loamy materials within the series control section. They differ from Waldron soils by having a mollic epipedon, a cambic horizon, and loamy materials within the series control section. They do not have carbonates throughout the control section for the calcareous class. The name is derived from the name of a historically significant monadnock in the survey area.
Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of 43 centimeters (17 inches) (Ap1 Ap2, and A horizons); cambic horizon - the zone from 43 to 142 centimeters (17 to 56 inches) (Bg1, Bg2 Bg3, and Bg4 horizons), and the loamy textured 2Cg horizon from 142 to 173 centimeters (56 to 68 inches).
ADDITIONAL DATA: Laboratory data; University of Missouri, Columbia, Missouri; Pedon ID M0721912 is data for the OSD typical pedon; Pedon IDs M0718306, M0702709, M0721906, M0721910, M0705119, M0721905, M0418305, and M0721911 are additional data used for the series range in characteristics.