LOCATION BASSETT            IA

BASSETT SERIES

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Mollic Hapludalfs

TYPICAL PEDON: Bassett loam, on a southwest-facing, convex slope of about 2 percent, in a cultivated field. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 20 centimeters; very dark brown (10YR 2/2) with some mixing of brown (10YR 4/3) loam; grayish brown (2.5Y 5/2) dry; weak fine granular structure; friable; slightly acid; clear smooth boundary. (13 to 25 centimeters thick)

E--20 to 25 centimeters; brown (10YR 4/3) loam; weak medium platy structure; friable; nearly continuous dark brown (10YR 3/3) and very dark grayish brown (10YR 3/2) coats on faces of peds; pale brown (10YR 6/3) and grayish brown (10YR 5/2) dry silt and sand coats on faces of peds; strongly acid; clear wavy boundary. (0 to 20 centimeters thick)

BE--25 to 36 centimeters; brown (10YR 4/3) loam; weak fine subangular blocky structure; friable; common fine pores; dark brown (10YR 3/3) coats on faces of peds; pale brown (10YR 6/3) dry silt and sand coats on faces of peds; concentration of rock fragments (2 to 75 millimeters in diameter) in 2 to 8 centimeter thick layer in the lower part; very strongly acid; clear smooth boundary. (0 to 20 centimeters thick)

2Bt1--36 to 56 centimeters; yellowish brown (10YR 5/6) loam; weak medium prismatic structure parting to moderate fine subangular blocky; friable; few fine and medium pores; brown (10YR 5/3) and yellowish brown (10YR 5/4) coats on faces of peds; few fine strong brown (7.5YR 5/6) accumulations (oxides); about 2 percent rock fragments (2 to 75 millimeters in diameter); very strongly acid; gradual smooth boundary.

2Bt2--56 to 76 centimeters; yellowish brown (10YR 5/6) and strong brown (7.5YR 5/6) loam; moderate medium prismatic structure parting to moderate fine subangular blocky; firm; common fine pores; few dark gray (10YR 4/1) clay films on faces of peds; brown (10YR 5/3) coats on faces of peds; few fine dark reddish brown (5YR 2/2) and yellowish red (5YR 4/6) accumulations (oxides); about 2 percent rock fragments (2 to 75 millimeters in diameter); common fine distinct grayish brown (2.5Y 5/2) redoximorphic depletions; strongly acid; gradual smooth boundary.

2Bt3--76 to 109 centimeters; yellowish brown (10YR 5/8) and grayish brown (2.5Y 5/2) loam; moderate coarse prismatic structure parting to weak medium subangular blocky; firm; few medium and fine pores; many grayish brown (2.5Y 5/2) coats and common dark gray (10YR 4/1) clay films on faces of peds and in pores and root channels; few fine dark reddish brown (5YR 2/2) and yellowish red (5YR 5/8) accumulations (oxides); about 2 percent rock fragments (2 to 75 millimeters in diameter); strongly acid; gradual smooth boundary.

2Bt4--109 to 150 centimeters; yellowish brown (10YR 5/8) and light olive gray (5Y 6/2) loam; very weak coarse prismatic structure parting to weak coarse subangular blocky; firm; few dark gray (10YR 4/1) clay films in root channels in upper part of horizon; few fine dark reddish brown (5YR 2/2) and few fine yellowish red (5YR 5/8) accumulations (oxides); about 2 percent rock fragments (2 to 75 millimeters in diameter);slightly acid; clear wavy boundary. (Combined thickness of the 2Bt horizons is 71 to 160 centimeters.)

2BC1--150 to 170 centimeters; yellowish brown (10YR 5/8) loam; extremely coarse prismatic structure dissected by few oblique fractures; very firm; many coarse prominent gray (5Y 6/1) redoximorphic depletions; about 4 percent rock fragments (2 to 75 millimeters in diameter); neutral; clear wavy boundary.

2BC2--170 to 185 centimeters; yellowish brown (10YR 5/8) loam; extremely coarse prismatic structure dissected by few oblique fractures; very firm; many coarse prominent gray (5Y 6/1) redoximorphic depletions; about 4 percent rock fragments (2 to 75 millimeters in diameter); strongly effervescent; moderately alkaline.

TYPE LOCATION: Major Land Resource Area (MLRA) 104-Eastern Iowa and Minnesota Till Prairies, Howard County, Iowa subset; about 10 miles west of the town of Lime Springs; located about 670 feet east and 500 feet north of the southwest corner of section 24, T. 100 N., R. 14 W.; USGS Lime Springs NW topographic quadrangle; lat. 43 degrees 27 minutes 33.8 seconds N. and long. 92 degrees 27 minutes 11.8 seconds W., NAD 83.

RANGE IN CHARACTERISTICS:
Depth to till--30 to 75 centimeters
Depth to carbonates--122 to 203 centimeters
Clay content in the particle-size control section (weighted average)--20 to 28 percent
Sand content in the particle-size control section (weighted average)--30 to 70 percent
Special feature--some pedons have a stone line or thin layer, 2 to 13 centimeters thick of gravelly and sandy materials at the base of the silty or loamy sediments

A or Ap horizon:
Hue--10YR
Value--2 or 3
Chroma1 to 3
Texture--loam or silt loam
Clay content--15 to 20 percent
Sand content--10 to 40 percent
Rock fragment content--1 to 10 percent
Reaction--strongly acid to neutral
Special features--when mixed to a depth of 18 centimeters, matrix value is 3 or less, moist, 5 or less, dry

E horizon (when present):
Hue--10YR
Value--3 to 5
Chroma--2 or 3
Texture--loam or silt loam
Clay content--15 to 20 percent
Sand content--10 to 40 percent
Rock fragment content--1 to 10 percent
Reaction--very strongly acid to neutral

In some cultivated areas the E horizon is mixed in the Ap horizon

BE horizon (when present):
Hue--7.5YR or 10YR
Value--4 or 5
Chroma--3 to 6
Texture--loam or silt loam
Clay content--15 to 25 percent
Sand content--10 to 55 percent
Rock fragment content--1 to 10 percent
Reaction--very strongly acid to slightly acid

In some pedons the BE horizon extends into the underlying till and may have fine faint accumulations of high chroma

2Bt horizon:
Hue--7.5YR to 5Y
Value--4 to 8
Chroma--1 to 8
Texture--loam, clay loam or sandy clay loam
Clay content--20 to 28 percent
Sand content--30 to 70 percent
Rock fragment content--2 to 15 percent
Reaction--very strongly acid to slightly acid
Low chroma matrix or redoximorphic depletions occur in the lower parts of this horizon

2BC horizons:
Hue--7.5YR to 5Y
Value--4 to 8
Chroma--1 to 8
Texture--loam
Clay content--18 to 27 percent, mean of 22 percent
Sand content--35 to 50 percent, mean of 44 percent
Rock fragment content--2 to 12 percent
Reaction--slightly acid to moderately alkaline
Moist bulk density--1.75 to 1.9 gm/cc

COMPETING SERIES: These are the Angus, Argyle, Blooming, Caleb, Cortland, Gara, Koronis, Lester, Newcomer, Orwood, Racine, Sebbo, Taopi, Waucoma, and Winneshiek series.
Angus--have carbonates within a depth of 137 centimeters and have a sand content of 30 to 45 percent throughout the series control section
Argyle--have matrix hues of 5YR or redder in the lower half of the series control section
Blooming--have a moist bulk density of less than 1.75 gm/cc in the lower third of the series control section
Caleb--have a moist bulk density of less than 1.75 gm/cc in the lower third of the series control section
Cortland--have a moist bulk density of less than 1.75 gm/cc in the lower third of the series control section and are in areas that have a mean annual air temperature range of 10 to 12 degrees C
Gara--have a clay content of 32 to 35 percent in the particle-size control section
Koronis--have carbonates within a depth of 91 centimeters and have a sand content of 50 to 70 percent in the lower third of the series control section
Lester--have carbonates within a depth of 137 centimeters and have a moist bulk density of less than 1.75 gm/cc in the lower third of the series control section
Newcomer--have a paralithic contact with sandstone within a depth of 102 centimeters
Orwood--have a sand content of 15 to 45 percent in the particle-size control section and do not have rock fragments in the series control section
Racine--do not have a frequently saturated zone within a depth of 1.8 meters in normal years
Sebbo--have a frequently saturated zone at a depth of 1 meter during the wettest periods of normal years and have 0 to 15 percent sandstone channers and chert gravel throughout the series control section
Taopi--have carbonates within a depth of 102 centimeters and have soft limestone or siltstone rock fragment content of 10 to 40 percent in the lower third of the series control section
Waucoma--have a lithic contact with limestone within a depth of 152 centimeters
Winneshiek--have a lithic contact with limestone within a depth of 102 centimeters

GEOGRAPHIC SETTING:
Parent material--30 to 75 centimeters of silty or loamy sediments and the underlying till
Landform--interfluves and side slopes on dissected till plains on the Iowan Erosion Surface
Slope--2 to 35 percent
Elevation--259 to 488 meters above sea level
Mean annual air temperature--7 to 11 degrees C
Mean annual precipitation--735 to 965 millimeters
Frost-free period--160 to 205 days

GEOGRAPHICALLY ASSOCIATED SOILS: Members of the typical catena include Kasson, Oran, Racine, and Skyberg soils.
Kasson--are at lower elevations on side slopes and have a saturated zone at a depth of 0.7 meter during the wettest periods of normal years
Oran--are at lower elevations on base slopes adjacent to drainageways and have a saturated zone at a depth of 0.4 meter during the wettest periods of normal years
Racine--are on higher elevations on shoulders and narrow summits and are not saturated within 1.8 meters in normal years
Skyberg--are at lower elevations in flat to concave drainageways and have a saturated zone at the soil surface during the wettest periods of normal years

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--moderately well drained--a saturated zone occurs between depths of 1 to 1.8 meters during March to June when precipitation is within one standard deviation of the 30 year mean of annual precipitation and both perched and apparent saturation can occur on this soil based on the season and intensity of rainfall during a given period of time
Saturated hydraulic conductivity--1.0 to 10.0 micrometers per second in the silty or loamy sediments and 0.01 to 1.0 micrometers per second in the till
Surface runoff potential--negligible to high

USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn, soybeans, small grains, and legume hay. The native vegetation is big bluestem, little bluestem, switchgrass, other grasses of the tall grass prairie and mixed deciduous trees.

DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic section--Dissected till plains
MLRAs--Eastern Iowa and Minnesota Till Prairies (104) and Illinois and Iowa Deep Loess and Drift (108)
Local physiographic area--Iowa Erosion Surface
LRR M; northeastern Iowa and possibly southeastern Minnesota
Extent--large

MLRA OFFICE RESPONSIBLE: St. Paul, Minnesota

SERIES ESTABLISHED: Iowa County, Iowa, 1965.

REMARKS:
Particle-size control section--the zone from a depth of 36 to 86 centimeters (2Bt1, 2Bt2 and 2Bt3 horizons);
series control section--the zone from the surface to a depth of 150 centimeters (Ap, E, BE, 2Bt1, 2Bt2, 2Bt3, and 2Bt4 horizons).

Diagnostic horizons and features recognized in this pedon include:
ochric epipedon--the zone from the surface to a depth of 25 centimeters (Ap and E horizons);
argillic horizon--the zone from a depth of 36 to 150 centimeters (2Bt1, 2Bt2, 2Bt3, and 2Bt4 horizons);
udic moisture regime.

Not all pedons meet the requirements of an argillic horizon (1.2 times clay increase from E horizon to 2Bt horizon). In these cases, the plow layer (Ap horizon) extends to the argillic horizon without transitional layers.

Some pedons have vertical seams or wedges of sand or loamy sand about 5 to 15 centimeters wide and about 0.9 to 1.2 meters deep extending downward from the stone line into the till.

Mollic subgroup based on colors and thickness of the ochric epipedon.

Cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.

Taxonomy version--Keys to Soil Taxonomy, tenth edition, 2006.

The MLRA 104 Steering Committee approved property edits to this series in February 2004.