LOCATION BASCO WIEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, mesic Mollic Hapludalfs
TYPICAL PEDON: Basco silt loam - on a 12 percent convex slope in a cultivated field at an elevation of about 287 meters. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 15 centimeters; very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; weak fine granular structure; friable; neutral; abrupt smooth boundary. (15 to 23 centimeters thick)
BE--15 to 28 centimeters; brown (10YR 4/3) silt loam; weak fine subangular blocky structure; friable; many earthworm casts; about 5 percent gravel; neutral; clear wavy boundary. (0 to 25 centimeters thick)
Bt1--28 to 41 centimeters; brown (10YR 4/3) silty clay loam; moderate very fine subangular blocky structure; firm; common distinct dark brown (10YR 3/3) clay films on faces of peds; about 3 percent gravel ; moderately acid; clear wavy boundary. (10 to 30 centimeters thick)
2Bt2--41 to 61 centimeters; reddish brown (5YR 4/4) silty clay; moderate fine subangular blocky structure; firm; common distinct dark reddish brown (2.5YR 3/4) clay films on faces of peds; about 10 percent gravel; moderately acid; clear wavy boundary.
2Bt3--61 to 84 centimeters; reddish brown (2.5YR 4/4) clay; strong medium angular blocky structure; very firm; common prominent dusky red (10R 3/4) clay films on faces of peds; about 10 percent chert gravel and dolostone channers; moderately acid; clear wavy boundary. (Combined thickness of the 2Bt horizons ranges from 25 to 76 centimeters.)
3BC--84 to 91 centimeters; brown (7.5YR 4/4) loamy sand; weak coarse subangular blocky structure; very friable; about 10 percent sandstone channers; moderately acid; clear wavy boundary. (0 to 10 centimeters thick)
3Cr--91 to 152 centimeters; brownish yellow (10YR 6/6) sandstone bedrock, shattered and partially weathered, becoming more consolidated with depth.
TYPE LOCATION: Major Land Resource Area (MLRA) 105-Northern Mississippi Valley Loess Hills, Dane County, Wisconsin; located about 3 miles southwest of Black Earth; 2,640 feet east and 800 feet south of the northwest corner of sec. 9, T. 7 N., R. 6 E. USGS Blue Mounds topographic quadrangle; latitude 43 degrees, 6', 6" N.; longitude 89 degrees, 47', 20" W.,NAD 83.
RANGE IN CHARACTERISTICS:
Depth to clayey pedisediment--25 to 61 centimeters
Depth to paralithic contact--51 to 102 centimeters; it is soft sandstone with thin finer-textured strata present in some pedons
Reaction-- naturally very strongly acid to slightly acid in the solum but ranges to neutral in the upper part, where the soil is limed
Rock fragment content--0 to 15 percent gravel and channers in the loess, 0 to 35 percent gravel and channers in the clayey pedisediment, 0 to 35 percent channers in the sandy residuum. The fragments are dolostone, chert, and sandstone in the loess and in the clayey pedisediment, and they are sandstone in the residuum.
A or Ap horizon:
Hue--10YR
Value--2 or 3
Chroma--2 or 3
Texture--silt loam
E horizon (when present):
Hue--10YR
Value--4 or 5
Chroma--2 or 3
Texture--silt loam
BE horizon:
Hue--10YR
Value--4 or 5
Chroma--3
Texture--silt loam
Bt horizon:
Hue--10YR
Value--4 or 5
Chroma--3 or 4
Texture--silt loam or silty clay loam.
2Bt horizon:
Hue--10R, 2.5YR, 5YR, or 7.5YR
Value--3 to 8
Chroma--1 to 8
Texture--silty clay loam, clay loam, silty clay, clay, or the gravelly analogs.
3BC horizon:
Hue--7.5YR or 10YR
Value--3 to 8
Chroma--2 to 6
Texture--sand, loamy sand, or the channery analogs.
3Cr horizon:
Hue--7.5YR or 10YR
Value of 5 to 8
Chroma of 1 to 6
COMPETING SERIES: This is the
Loper series. Related soils are the
Derinda and
Schapville series.
Loper--dominated by amorphous materials in the upper part of the series control section and do not have a paralithic contact within the series control section Derinda and Schapville--do not have sandstone bedrock within a depth of 102 centimeters
GEOGRAPHIC SETTING:
Parent Material--thin layer of loess underlain by clayey pedisediment and sandy residuum weathered from the underlying sandstone
Landscapebedrock controlled hills
Landform--rounded ridgetops and convex side slopes
Slope--2 to 30 percent
Elevation225 to 400 meters above sea level
Mean annual air temperature9 to 11 degrees C
Mean annual precipitation711 to 864 millimeters
Frost-free period145 to 205 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Fivepoints and
Keyesville near the Type Location.
Fivepoints--have a loamy-skeletal contact at less than 50 centimeters, a lithic dolostone contact at 51 to 102 centimeters and are on positions higher on the landscape
Keyesville--are loamy-skeletal and are on positions lower on the landscape
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained--a saturated zone does not occur within a depth of 1.8 meters in normal yearsSaturated hydraulic conductivity--1.41-14.11 micrometers per second (moderately slow or moderate) in the loess, .01-.2 micrometers per second (very slow or slow) in the clayey pedisediment, 42.34-141.14 micrometers per second (rapid) in the sandy residuum, 1.41-14.11 micrometers per second (moderately slow or moderate) in the sandstone
USE AND VEGETATION: Most areas are used for cropland. Common crops are corn, small grain, and hay. Some areas are used for pastureland or woodland. Native vegetation is northern red oak, white oak, black oak, sugar maple, and American basswood with an understory of prairie grasses.
DISTRIBUTION AND EXTENT:
Physiographic division--Interior Plains
Physiographic Province--Central Lowland
Physiographic sections--Wisconsin driftless section
MLRAs--Northern Mississippi Valley Loess Hills (105)
LRR M; southwestern Wisconsin
Extentmoderate
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Dane County, Wisconsin, 1972.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
ochric epipedon - 0 to 28 centimeters (Ap, BE)
argillic horizon - 28 to 84 centimeters (Bt1, 2Bt2, 2Bt3);
paralithic contact - 91 centimeters (3Cr);
Clayey pedisediment is from the mass wasting of surrounding dolostone formations that dominate the area. Sandstone is the Jordan formation and some areas have thin strata of finer texture in the bedrock.
The range in characteristics of the A horizon may include pedons that have a Mollic epipedon; further investigation may be necessary to determine taxonomic placement of the Basco soils.