LOCATION FLOYD IA+MN WI
Established Series
Rev. RLB-NRS-AAC
02/2013
FLOYD SERIES
The Floyd series consists of very deep, somewhat poorly drained soils formed in 75 to 150 centimeters of loamy sediments and in the underlying till. These soils are on concave foot slopes adjacent to upland drainageways on dissected till plains. Slope ranges from 0 to 5 percent. Mean annual air temperature is about 7 degrees C. Mean annual precipitation is about 825 millimeters.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aquic Pachic Hapludolls
TYPICAL PEDON: Floyd loam, on a southwest-facing slope of about 3 percent, in a bluegrass pasture. (Colors are for moist soil unless otherwise stated.)
A1--0 to 41 centimeters; black (10YR 2/1) loam, dark gray (10YR 4/1) dry; weak fine granular structure; friable; about 2 percent fine and medium gravels; many roots; neutral; gradual smooth boundary.
A2--41 to 60 centimeters; very dark grayish brown (2.5Y 3/2) loam, grayish brown (2.5Y 5/2) dry; weak fine subangular blocky structure; friable; about 2 percent fine and medium gravels; few roots; very dark gray (10YR 3/1) coats on faces peds; neutral; gradual smooth boundary. (Combined thickness of the A horizon is 50 to 60 centimeters.)
Bw1--60 to 84 centimeters; olive brown (2.5Y 4/4) sandy clay loam; weak fine subangular blocky structure; friable; few roots; common fine distinct dark grayish brown (2.5Y 4/2) redoximorphic depletions; few fine prominent yellowish brown (10YR 5/8) redoximorphic concentrations in the lower part; a stone line (pebbles, 1 to 3 centimeters in diameter) at a depth of 79 centimeters; about 2 percent fine and medium gravels throughout; neutral; clear smooth boundary.
Bw2--84 to 104 centimeters; yellowish brown (10YR 5/8) sandy loam; weak medium subangular blocky structure; very friable; about 2 percent fine and medium gravels; neutral; clear smooth boundary. (Combined thickness of the Bw horizon is 35 to 60 centimeters.)
2Bw3--104 to 127 centimeters; yellowish brown (10YR 5/8) loam; weak medium subangular blocky structure; firm; common distinct grayish brown (2.5Y 5/2) coats on faces of peds; many fine prominent light olive brown (2.5Y 5/4) redoximorphic concentrations; about 5 percent mixed rock fragments; neutral; clear wavy boundary. (20 to 35 centimeters thick)
2BC--127 to 200 centimeters; yellowish brown (10YR 5/6) loam; moderate coarse prismatic structure dissected by few oblique fractures; very firm; common fine prominent grayish brown (2.5Y 5/2) redoximorphic depletions; about 5 percent mixed rock fragments; slightly effervescent; moderately alkaline.
TYPE LOCATION: Major Land Resource Area (MLRA) 104-Eastern Iowa and Minnesota Till Prairies, Bremer County, Iowa subset; about 3 miles west and 2 miles south of Tripoli; located about 266 feet west and 97 feet north of the southeast corner of section 14, T. 92 N., R. 13 W.; USGS Tripoli topographic quadrangle; lat. 42 degrees 46 minutes 26 seconds N. and long. 92 degrees 20 minutes 18.3 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon--50 to 60 centimeters
Depth to till--75 to 150 centimeters
Depth to carbonates--114 to greater than 200 centimeters
Rock fragment content - 0 to 3 percent boulders (more than 250 millimeters in diameter) igneous, metamorphic and dolomitic on or below the surface.
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 55 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
Chroma--1 or 2
Texture--loam, clay loam, silty clay loam, or silt loam
Clay content--18 to 30 percent
Sand content--15 to 50 percent
Rock fragment content--0 to 5 percent
Reaction--slightly acid or neutral
Moist bulk density--1.20 to 1.60 g/cc
Bw horizon (upper part):
Hue--10YR or 2.5Y
Value--4 or 5
Chroma, when hue is 10YR--2
Chroma, when hue is 2.5Y--2 to 4
Texture--loam or sandy clay loam
Clay content--18 to 30 percent
Sand content--30 to 60 percent
Rock fragment content--0 to 5 percent
Reaction--slightly acid or neutral
Moist bulk density--1.30 to 1.65 g/cc
Where matrix colors have chroma higher than 2, redoximorphic depletions have chroma of 2
Bw horizon (lower part):
Hue--10YR or 2.5Y
Value--4 or 5
Chroma--2 to 8
Texture--sandy loam, loam, sandy clay loam or loamy sand
Clay content--10 to 25 percent
Sand content--40 to 85 percent
Rock fragment content--0 to 5 percent
Reaction--slightly acid or neutral
Moist bulk density--1.30 to 1.65 g/cc
2Bw horizon:
Hue--10YR or 2.5Y
Value--4 or 5
Chroma--2 to 8
Texture--loam, clay loam, or sandy clay loam
Clay content--18 to 28 percent
Sand content--30 to 70 percent
Rock fragment content--2 to 12 percent
Reaction--slightly acid or neutral
Moist bulk density--1.6 to 1.9 g/cc
2BC horizon:
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--1.6 to 1.9 g/cc
COMPETING SERIES: There are no competing series in the same family.
GEOGRAPHIC SETTING:
Parent material--75 to 150 centimeters of loamy sediments and in the underlying till
Landform--concave foot slopes adjacent to upland drainageways on dissected till plains
Slope--0 to 5 percent
Elevation--200 to 470 meters above sea level
Mean annual air temperature--4 to 10 degrees C
Mean annual precipitation--685 to 965 millimeters
Frost-free period--135 to 205 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Clyde,
Kenyon,
Readlyn, and
Tripoli series.
Clyde--are at slightly lower landscape positions in swales and upland drainageways and frequently saturated at the soil surface during the wettest periods of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation
Kenyon--are at higher landscape positions on side slopes and interfluves and are frequently saturated at a depth of 1.2 meters during the wettest periods of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation
Readlyn--are at landscape positions similar to those of the Floyd soils and have a moist bulk density of 1.75 to 1.9 g/cc within a depth of 75 centimeters
Tripoli--are at slightly lower landscape positions in swales and upland drainageways and frequently saturated at the soil surface during the wettest periods of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--somewhat poorly drained--a frequently saturated zone occurs between depths of 0.3 and 1 meter during April to June in years when precipitation is within one standard deviation of the 30 year mean of annual precipitation, 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 loamy sediments and 0.01 to 1.0 micrometers per second in the till
USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn and soybeans. The native vegetation is big bluestem, little bluestem, switchgrass, and other grasses of the tall grass prairie.
DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic sections--Dissected till plains, Western lake section and Wisconsin driftless section
MLRAs--Eastern Iowa and Minnesota Till Prairies (104), Northern Mississippi Valley Loess Hills (105) and Central Wisconsin and Minnesota Thin Loess and Till, Southern Part (90B)
LRR M; northeast Iowa, southeast Minnesota, and southwestern Wisconsin
Extent--large
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Floyd County, Iowa, 1922.
REMARKS:
Particle-size control section--the zone from a depth of 25 to 100 centimeters;
series control section--the zone from the surface to a depth of 200 centimeters.
Diagnostic horizons and features recognized in this pedon include:
mollic epipedon--the zone from the surface to a depth of 60 centimeters (A1 and A2 horizons);
cambic horizon--the zone from a depth of 60 to 200 centimeters (Bw1, Bw2, 2Bw3, and 2BC horizons);
udic moisture regime.
Some pedons have vertical seams or wedges of sand or loamy sand about 5 to 30 centimeters wide and about 0.9 to 1.2 meters deep extending downward from the stone line into the glacial till.
Cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Taxonomy version--Keys to Soil Taxonomy, eleventh edition, 2010.
ADDITIONAL DATA:
Pedon data from soil characterization lab at Iowa State University and the KSSL was evaluated in January 2013 in revising the Range in Characteristics.
Laboratory data - National Soil Survey Laboratory, Lincoln, Nebraska - Pedon ID: 73IA017001, 74MN109(1804), 75MN109(1971), S04IA-107-003, S04-IA017-006 (http://ncsslabdatamart.sc.egov.usda.gov/)
National Cooperative Soil Survey
U.S.A.