LOCATION TOBINSPORT INEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, active, mesic Ultic Hapludalfs
TYPICAL PEDON: Tobinsport silt loam on a 1 percent slope in a cultivated field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 9 inches; brown (10YR 4/3) silt loam; moderate fine subangular blocky structure; friable; common fine roots; neutral; abrupt smooth boundary. (6 to 10 inches thick)
Bt1-9 to 12 inches; yellowish brown (10YR 5/4) silt loam; moderate medium subangular blocky structure; friable; few fine roots; common discontinuous distinct brown (10YR 4/3) organio-clay films on faces of peds; neutral; clear wavy boundary. (0 to 6 inches thick)
Bt2--12 to 18 inches; strong brown (7.5YR 5/6) silt loam; moderate medium subangular blocky structure; friable; few fine roots; many continuous distinct brown (7.5YR 5/4) clay films on faces of peds and in pores; few discontinuous brown (10YR 4/3) organic coatings on faces of peds; slightly acid; clear wavy boundary.
Bt3--18 to 27 inches; strong brown (7.5YR 5/6) silt loam; moderate medium subangular blocky structure; friable; many continuous distinct brown (7.5YR 5/4) clay films on faces of peds; strongly acid; clear wavy boundary. (Combined thickness of the Bt horizons ranges from 14 to 30 inches.)
2Bt4--27 to 33 inches; strong brown (7.5YR 5/6) loam (increase in very fine sand); moderate fine subangular blocky structure; friable; many discontinuous distinct brown (7.5YR 5/4) clay films on faces of peds; very strongly acid; clear wavy boundary.
2Bt5--33 to 41 inches; strong brown (7.5YR 5/6) loam; moderate fine subangular blocky structure; friable; many discontinuous distinct brown (7.5YR 5/4) clay films on faces of peds; very strongly acid; clear wavy boundary.
2Bt6--41 to 52 inches; strong brown (7.5YR 5/6) very fine sandy loam; moderate fine subangular blocky structure; friable; common discontinuous distinct brown (7.5YR 5/4) clay films on faces of peds; very strongly acid; clear wavy boundary. (Combined thickness of the 2Bt horizons range from 10 to 40 inches)
3C&Bt1--52 to 60 inches; dark yellowish brown (10YR 4/4) loamy fine sand (C), and strong brown (7.5YR 5/6) fine sandy loam (Bt); weak fine subangular blocky structure; very friable; common discontinuous distinct brown (7.5YR 5/4) clay films on faces of peds; very strongly acid; clear wavy boundary.
3C&Bt2--60 to 75 inches; brown (10YR 4/3) loamy fine sand (C), and yellowish brown (10YR 5/4) fine sandy loam (Bt) (fine and medium); weak fine granular structure; very friable; few discontinuous faint brown (7.5YR 5/4) clay bridging; very strongly acid; clear wavy boundary.
3C&Bt3--75 to 80 inches; brown (10YR 4/3) loamy fine sand (C), and yellowish brown (10YR 5/4) fine sandy loam (Bt) (fine and medium); weak fine granular structure; very friable; few discontinuous faint brown (7.5YR 4/4) clay bridging; prominent black (10YR 2/1) iron-manganese oxide stains; very strongly acid.
TYPE LOCATION: Perry County, Indiana; 1,475 feet west and 100 feet south of the northeast corner of section 32, T. 7 S., R. 2 W. USGS Cloverport, IN topographic quadrangle: lat. 37 degrees 52 minutes 0 seconds N. and long. 86 degrees 38 minutes 50 seconds W.
RANGE IN CHARACTERISTICS: The depth to the base of the argillic horizon is 60 to more than 80 inches. The particle-size control section averages 24 to 30 percent clay and 6 to 15 percent fine and coarser sand. Depth to a 3C&Bt horizon formed in sand is greater than 40 inches.
The upper part of the control section (Ap horizon) has hue of 10YR, value of 4 or 5, and chroma of 3 or 4. Reaction is strongly acid or very strongly acid in unlimed areas, and ranges to neutral in limed areas.
The second part of the control section (Bt and BE horizons) has hue of 10YR or 7.5YR, value of 4 to 6, and chroma of 4 to 6. It is silt loam or silty clay loam and contains 22 to 32 percent clay and 5 to 15 percent fine and coarser sand. Reaction is very strongly acid or strongly acid in unlimed areas, and ranges to neutral in the upper part in limed areas.
The third part of the control section (2Bt horizon) has hue of 10YR or 7.5YR, value of 5, and chroma of 4 to 8. It is fine sandy loam, very fine sandy loam, or loam, and averages 15 to 22 percent clay and 40 to 60 percent sand. Reaction is strongly acid or very strongly acid.
The lower part of the control section (3C&Bt horizon) has hue of 10YR or 7.5YR, value of 4 to 6 and chroma of 3 to 8. The Bt part (bands and lamallae) is fine sandy loam, loamy fine sand or very fine sandy loam. The C part is loamy very fine sand or loamy fine sand. This part of the control section averages 65 to 85 percent sand. The combined total of fine sand and very fine sand averages from 65 to 80 percent. Reaction is strongly acid or very strongly acid.
COMPETING SERIES: These are the Alford, Cidermill, Eilertsen, Elk, Elkinsville, Parke, Pike, Rosine, Vernonia, Wellrock (T) and Wellston series. Cidermill soils have rock fragments in the series control section. Eilertsen soils have an umbric epipedon. Elk soils average less than 65 percent sand in the lower part of the series control section. Elkinsville, Parke, and Pike soils average less than 65 percent fine and very fine sand in the lower part of the series control section. Rosine soils average more than 22 percent clay in the lower part of the argillic horizon. Vernonia, Wellrock, and Wellston soils have a paralithic or lithic contact in the series control section.
GEOGRAPHIC SETTING: Tobinsport soils are on summits, shoulders and backslopes of loess covered dunes on stream terraces. They formed in 20 to 40 inches of loess and the underlying loamy and sandy materials. Slopes are dominantly 0 to 4 percent, but range up to 45 percent. Mean annual temperature ranges from 53 to 57 degrees F, and the mean annual precipitation ranges from 40 to 46 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alford, Alvin, Bloomfield, and Princeton soils. The well drained, more silty Alford soils are on similar landform positions. The well drained Alvin, and Princeton soils and the somewhat excessively drained, more sandy Bloomfield soils are on similar landform positions.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate in the upper part of the solum and rapid in the lower part. Runoff is slow to very rapid.
USE AND VEGETATION: Most nearly level and gently sloping areas are used for growing corn, soybeans, wheat, and hay. Most steep and very steep areas are used for woodland and wildlife habitat. Native vegetation is mixed, deciduous hardwood forest.
DISTRIBUTION AND EXTENT: Southern Indiana. The acreage is of small extent in MLRA 120.
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana
SERIES PROPOSED: Perry County, Indiana, 1993. The series is named for a small town in the southern part of Perry County.
REMARKS: Diagnostic surface and subsurface horizons and features recognized in this pedon are: 1) Ochric epipedon- the zone from 0 to 9 inches (Ap horizon); 2) Argillic horizon- the zone from 9 to 80 inches (Bt1, Bt2, 2Bt3, 2Bt4, 2Bt5, Bt part of 3C/Bt horizons).
ADDITIONAL DATA: Data on pedon number S93IN123-002 is at the NSSC, Lincoln, NE.