LOCATION LECOMA MOEstablished Series
TAXONOMIC CLASS: Fine-loamy, siliceous, active, mesic Typic Paleudalfs
TYPICAL PEDON: Lecoma silt loam on a northeast facing slightly convex slope of 6 percent in pasture at an elevation of 950 feet. (Colors are for moist soil unless otherwise stated.)
Ap1--0 to 2 inches; dark yellowish brown (10YR 3/4) silt loam, pale brown (10YR 6/3) dry; weak very fine and fine granular structure; very friable; many very fine and fine roots; common very fine and fine tubular pores; neutral; clear wavy boundary. (1 to 10 inches thick)
Ap2--2 to 9 inches; dark yellowish brown (10YR 3/4) silt loam; weak fine and medium subangular blocky structure; very friable; common very fine and fine roots; common very fine and fine tubular pores; neutral; gradual wavy boundary. (Combined thickness of the Ap or A horizon is 3 to 12 inches)
Bt1--9 to 14 inches; dark yellowish brown (10YR 4/4) silt loam; moderate fine and medium subangular blocky structure; friable; common very fine and fine roots; common very fine and fine tubular pores; common faint clay films on faces of peds; neutral; clear wavy boundary.
Bt2--14 to 20 inches; brown (7.5YR 4/4) silt loam; moderate fine prismatic structure; friable; common very fine and fine roots; common fine and few medium tubular pores; many faint clay films on faces of peds; slightly acid; clear wavy boundary.
Bt3--20 to 31 inches; strong brown (7.5YR 4/6) silt loam; moderate fine prismatic structure; firm; common very fine and few fine roots; common very fine and few fine tubular pores; many faint clay films on faces of peds; moderately acid; gradual wavy boundary. (Combined thickness of the Bt horizon is 8 to 30 inches)
2Bt4--31 to 44 inches; yellowish red (5YR 4/6) loam; moderate fine prismatic structure parting to moderate fine subangular blocky; firm; common very fine and few fine roots; common very fine and few fine tubular pores; common distinct clay films in pores and on faces of peds; common silt coatings in pores and on faces of peds; few fine manganese stains and concretions; strongly acid; gradual wavy boundary. (0 to 16 inches thick)
2Bt5--44 to 56 inches; yellowish red (5YR 4/6) and red (2.5YR 4/6) loam; moderate fine prismatic structure; firm; few very fine roots; common very fine and few fine tubular pores; common distinct clay films in pores and on faces of peds; common silt coatings in pores and on faces of peds; common fine and medium manganese stains and concretions; 2 percent sandstone and chert gravel; strongly acid; gradual wavy boundary. (5 to 20 inches thick)
2Bt6--56 to 63 inches; red (2.5YR 4/6) and dark red (2.5YR 3/6) loam; weak fine and medium prismatic structure; firm; few very fine roots; few very fine and few fine tubular pores; many faint clay films on faces of peds; few fine silt coatings in pores and on faces of peds; few fine manganese stains and concretions; 5 percent sandstone and chert gravel; strongly acid.
TYPE LOCATION: Phelps County, Missouri; about 3 miles southeast of Elk Prairie, 1,100 feet north and 540 feet east of the southwest corner of sec. 23, T. 36 N., R. 7 W; USGS Lecoma, Missouri quadrangle, lat. 37 degrees 49 minutes 21.2 seconds N. and 91 degrees 40 minutes 18 seconds W.; UTM zone 15, NAD 83, UTM 616,908 easting and 4,186,958 northing.
RANGE IN CHARACTERISTICS: The particle size control section averages 15 to 40 percent fine and coarser sand, 18 to 30 percent clay, and 0 to 10 percent gravel.
The Ap or A horizon has color value of 3 to 5 moist, 6 or 7 dry, and chroma of 2 to 4. It is silt loam, fine sandy loam, or loam. Reaction is very strongly acid to neutral.
The E horizon, where present, has hue of 10YR, value of 4 or 5, and chroma of 3 or 4.
The Bt horizon has hue of 5YR or 10YR, value of 4 to 6, and chroma of 3 to 6. Mottles, when present, have hue of 2.5YR to 10YR, value of 4 or 5, and chroma of 3 to 6. Gravel content ranges from 0 to 10 percent. It is silt loam, silty clay loam, clay loam, or loam. Reaction is strongly acid to neutral.
The 2Bt horizon has hue of 2.5YR to 7.5YR, value of 3 to 6, and chroma of 3 to 6. Mottles, when present, have hue of 2.5YR to 10YR, value of 4 to 7, and chroma of 3 to 8. Iron depletions with chroma 2 or less may occur below a depth of 40 inches. Gravel content ranges from 0 to 10 percent. It is loam, sandy clay loam, clay loam, or silt loam. Reaction is extremely acid to slightly acid.
COMPETING SERIES: These are the Gallia and Portia series. Gallia soils have a higher content of sand and gravel in the lower solum and substratum. Portia soils have redder colors in the upper part of the argillic, and more clay in the lower part of the profile.
GEOGRAPHIC SETTING: Lecoma soils are on gently sloping to strongly sloping stream terraces and foot slopes. Slopes range from 1 to 15 percent. The soil formed in alluvium and colluvium derived predominantly from sandstone. Average annual temperature ranges from 53 to 57 degrees F. and average annual precipitation ranges from 41 to 46 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bender, Kaintuck, Razort, and Yelton soils. Bender soils are moderately deep to sandstone bedrock. Kaintuck soils are coarse-loamy. Razort soils have darker surface horizons. Yelton soils have fragipans. Bender soils are on upland sideslopes. Kaintuck soils are on floodplains. Razort soils are on floodplains and low terraces. Yelton soils are on foot slopes and remnant terraces in uplands.
DRAINAGE AND PERMEABILITY: Well drained, low to medium surface runoff index; moderate permeability. The saturated hydraulic conductivity is moderately high.
USE AND VEGETATION: Nearly all areas have been cleared. They are used for hay or pasture.
DISTRIBUTION AND EXTENT: The Ozark region (MLRA 116A) of Missouri. The series is of medium extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Phelps County, Missouri, 1999.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
ochric epipedon - the zone from the surface of the soil to a depth of 9 inches (Ap1 and Ap2 horizons);
argillic horizon - the zone from 9 to 60 inches or more (Bt1 through 2Bt6 horizons);
udic moisture regime
ADDITIONAL DATA: University of Missouri soil characterization laboratory reference number M9016102.