LOCATION CALWOODS MOEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Aeric Epiaqualfs
TYPICAL PEDON: Calwoods silt loam - on a 3 percent convex west-facing slope in a forested tract. (Colors are for moist soil unless otherwise stated.)
A--0 to 4 inches; dark grayish brown (10YR 4/2) and very dark grayish brown (10YR 3/2) silt loam, dark grayish brown (10YR 4/2) kneaded, light brownish gray (10YR 6/2) dry; moderate fine granular structure; friable; common roots; strongly acid; clear smooth boundary.
E--4 to 8 inches; brown (10YR 5/3) silt loam; weak fine subangular blocky structure; friable; common roots; few dark grayish brown (10YR 4/2) coatings on faces of peds; few fine dark concretions (Fe and Mn oxides); very strongly acid; clear smooth boundary. (Combined thickness of the A and E horizon is 4 to 13 inches.)
BE--8 to 12 inches; yellowish brown (10YR 5/4) silty clay loam; common fine prominent strong brown (7.5YR 5/6) and few fine distinct light brownish gray (10YR 6/2) mottles; moderate fine subangular blocky structure; friable; common roots; many faint brown (10YR 5/3) silt coatings on faces of peds; few fine dark concretions (Fe and Mn oxides); very strongly acid; clear smooth boundary. (0 to 6 inches thick)
Btg1--12 to 26 inches; grayish brown (10YR 5/2) silty clay; many fine prominent red (2.5YR 4/6) and dark red (2.5YR 3/6) and few fine distinct yellowish brown (10YR 5/6) mottles; moderate very fine subangular blocky structure; firm; common roots; many faint dark grayish brown (10YR 4/2) clay films on faces of peds; very strongly acid; clear smooth boundary.
Btg2--26 to 33 inches; grayish brown (2.5Y 5/2) silty clay; many fine prominent yellowish brown (10YR 5/4) and few fine prominent strong brown (7.5YR 5/6) mottles; weak very fine subangular blocky structure; firm; few fine roots; many faint dark grayish brown (10YR 4/2) clay films on faces of peds; very strongly acid; gradual wavy boundary.
Btg3--33 to 40 inches; grayish brown (2.5Y 5/2) silty clay loam; many fine prominent yellowish brown (10YR 5/4) and few fine prominent yellowish brown (10YR 5/8) mottles; weak fine subangular blocky structure; firm; few fine roots; common faint dark grayish brown (10YR 4/2) clay films on faces of peds; strongly acid; clear smooth boundary. (Combined thickness of the Btg horizon is 20 to 48 inches.)
2Cg--40 to 60 inches; light brownish gray (2.5Y 6/2) silty clay loam; common fine prominent yellowish brown (10YR 5/8), few fine prominent dark yellowish brown (10YR 4/4) and few fine distinct brown (10YR 5/3) mottles; massive; firm; few fine roots; common sand grains; moderately acid.
TYPE LOCATION: Montgomery County, Missouri; 5 miles north of Montgomery City; 920 feet south and 100 feet west of the northeast corner, sec. 6, T. 6 N., R. 5 W.
RANGE IN CHARACTERISTICS: Depth to the 2Btg or 2Cg horizon is 27 to 54 inches.
The Ap or A horizon has dominant color value of 4 or 5 and chroma of 2 or 3. If an A horizon has value of 3, thickness is less than 6 inches. The E horizon has color value of 5 to 7 and chroma of 2 to 4. Texture commonly is silt loam, but may be silty clay loam. Reaction is very strongly acid to neutral.
The Btg horizon has hue of 10YR or 2.5Y, value of 4 to 6 and chroma of 2 or 3. It is silty clay, clay, or silty clay loam. Reaction is very strongly acid or strongly acid in the upper part and strongly acid to slightly acid in the lower part. The upper part of the Btg horizon contains many prominent reddish mottles and the lower part contains strong brown or yellowish brown mottles. Some pedons have 2Btg horizons with clay loam or silty clay loam texture. The particle size control section averages between 45 and 60 percent clay.
The 2C horizon has hue of 2.5Y or 5Y, value of 5 or 6 and chroma of 2. It is silty clay loam or clay loam. Reaction is moderately acid to neutral.
COMPETING SERIES: These are the Bluford, Hurst, Keomah, Kernan, Rathbun, Sabina and Waxpool series. Bluford soils are brittle in the series control section where having a 2Btx horizon. Hurst soils do not have the red mottles in the upper part of the solum. Keomah, Kernan, and Sabina soils average less than 45 percent clay in the particle size control section. Rathbun soils do not have red mottles or 2Btg or 2Cg horizons.
GEOGRAPHIC SETTING: Calwoods soils are on nearly level and gently sloping broad summits. Slopes range from 1 to 5 percent. They formed in loess or loess and pedisediment or glacial till. The mean annual temperature ranges from 50 to 55 degrees F, and mean annual precipitation ranges from 35 to 40 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hatton, Lindley, Marion, Mexico and soils. Hatton and Lindley soils have higher chroma matrix in the B horizons and, in addition, Lindley soils formed in till. Marion soils have an abrupt textural change between the E and B horizons. Mexico soils have moist value and chroma of 3 or less in the surface horizon. Hatton, Marion and Mexico soils are in similar positions and Lindley soils are downslope.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Runoff is slow. Permeability is very slow. The upper depth of a perched water table is at 1.0 to 2.5 feet during November to April.
USE AND VEGETATION: Some areas are used to grow corn and soybeans. Other uses are pasture and woodland. Native vegetation is hardwood forest.
DISTRIBUTION AND EXTENT: Central and northeastern Missouri. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Knox, Monroe, and Shelby Counties, Missouri, 1973.
REMARKS: Diagnostic horizons and features recognized in this series are: ochric epipedon - the zone from the surface of the soil to a depth of 12 inches (Ap, E and BE horizons); argillic horizon - the depth from approximately 12 inches to 40 inches (Btg1, Btg2 and Btg3 horizons).