LOCATION READLYN IA+MNEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aquic Hapludolls
TYPICAL PEDON: Readlyn loam, on a 2 percent slope, in a permanent pasture. (Colors are for moist soil unless otherwise stated.)
A1--0 to 23 centimeters; black (10YR 2/1) loam; weak fine granular structure; friable; many fine roots; moderately acid; clear wavy boundary.
A2--23 to 38 centimeters; very dark grayish brown (10YR 3/2) loam; weak fine granular and subangular blocky structure; friable; common fine roots; strongly acid; clear wavy boundary. (Combined thickness of the A horizon is 35 to 49 centimeters.)
BA--38 to 48 centimeters; very dark grayish brown (10YR 3/2) loam; weak fine and medium subangular blocky structure; friable; common fine roots; strongly acid; clear wavy boundary. (0 to 18 centimeters thick)
Bw--48 to 61 centimeters; dark grayish brown (10YR 4/2) loam; weak fine subangular blocky structure; friable; common fine roots; strongly acid; gradual wavy boundary. (10 to 20 centimeters thick)
2Bg1--61 to 89 centimeters; yellowish brown (10YR 5/6) and grayish brown (10YR 5/2) clay loam; weak fine subangular blocky structure; friable; common fine roots; few fine distinct strong brown (7.5YR 5/8) redoximorphic concentrations; about 2 percent subrounded (2 to 75 millimeters) mixed rock fragments; moderately acid; gradual wavy boundary.
2Bg2--89 to 117 centimeters; grayish brown (10YR 5/2) and yellowish brown (10YR 5/6) clay loam; moderate fine and medium subangular blocky structure; firm; common very fine roots; very few fine and medium cylindrical very dark gray (10YR 3/1) clay coats on surfaces along pores and root channels; few fine prominent strong brown (7.5YR 5/8) redoximorphic concentrations; about 2 percent subrounded (2 to 75 millimeters) mixed rock fragments; slightly acid; gradual wavy boundary. (Combined thickness of the 2Bg horizon is 40 to 90 centimeters.)
2BCg--117 to 152 centimeters; grayish brown (10YR 5/2) and yellowish brown (10YR 5/6) loam; moderate coarse and extremely coarse prismatic structure dissected by few oblique fractures; very firm; very few fine and medium cylindrical very dark gray (10YR 3/1) clay coats on surfaces along pores and root channels; few fine prominent strong brown (7.5YR 5/8) redoximorphic concentrations; about 5 percent subrounded (2 to 75 millimeters) mixed rock fragments; slightly effervescent; slightly alkaline; gradual wavy boundary.
2BC--152 to 200 centimeters; yellowish brown (10YR 5/8) and grayish brown (10YR 5/2) loam; moderate coarse and extremely coarse prismatic structure dissected by few oblique fractures; very firm; very few fine and medium cylindrical very dark gray (10YR 3/1) clay coats on surfaces along pores and root channels; few fine faint strong brown (7.5YR 5/8) redoximorphic concentrations; about 2 percent subrounded (2 to 75 millimeters) 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 1.5 miles north of Readlyn; located about 540 feet north and 2,375 feet east of the southwest corner of section 35, T. 92 N., R. 12 W.; USGS Readlyn topographic quadrangle; lat. 42 degrees 43 minutes 52.0 seconds N. and long. 92 degrees 13 minutes 47.4 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon--30 to 49 centimeters
Depth to carbonates--more than 100 centimeters
Depth to till--30 to 75 centimeters
Clay content in the particle-size control section (weighted average)--22 to 30 percent
Sand content in the particle-size control section (weighted average)--30 to 50 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
Base saturation of the upper part of the series control section--50 to 70 percent
Ap or A horizon:
Hue--10YR
Value--2 or 3
Chroma--1 or 2
Texture--loam, clay loam, silty clay loam, or silt loam
Clay content--20 to 30 percent
Sand content--20 to 40 percent
Rock fragment content--0 to 10 percent
Reaction--strongly acid to slightly acid
AB or BA horizon (when present):
Hue--10YR
Value--3 or 4
Chroma--2 or 3
Texture--loam, clay loam, silty clay loam, or silt loam
Clay content--20 to 30 percent
Sand content--20 to 40 percent
Rock fragment content--0 to 10 percent
Reaction--strongly acid to slightly acid
Bg or Bw horizon (when present):
Hue--10YR or 2.5Y
Value--4 or 5
Chroma--2 to 4
Texture--loam, clay loam, silty clay loam, or silt loam
Clay content--20 to 30 percent
Sand content--20 to 40 percent
Rock fragment content--0 to 10 percent
Reaction--strongly acid to slightly acid
2Bg or 2Bw (when present) horizon:
Hue--10YR or 2.5Y
Value--4 or 5
Chroma--2 to 8
Texture--loam, clay loam, or sandy clay loam
Clay content--22 to 32 percent
Sand content--30 to 50 percent
Rock fragment content--2 to 12 percent
Reaction--strongly acid to slightly alkaline
2BC and 2C (when present) horizon:
Hue--7.5YR to 2.5Y
Value--4 to 6
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 g/cc
COMPETING SERIES: These are the
Arkton,
Crippin,
Fostoria,
Kensett,
Merton,
Nicollet,
Normania,
Ottosen,
Snider,
Stone,
Walnut Grove, and
Wilmonton series.
Arkton--have carbonates within a depth of 25 centimeters
Crippin--have carbonates within a depth of 25 centimeters
Fostoria--do not have rock fragments in the series control section
Kensett--have limestone bedrock within a depth of 100 centimeters
Merton--have a moist bulk density of 1.5 to 1.7 g/cc in the lower half of the series control section
Nicollet--have a moist bulk density of less than 1.75 g/cc in the lower half of the series control section
Normania--have carbonates within a depth of 75 centimeters
Ottosen--have a moist bulk density of 1.5 to 1.7 g/cc in the series control section
Snider--do not have rock fragments in the series control section
Stone--have limestone bedrock within a depth of 150 centimeters
Walnut Grove--have carbonates within a depth of 100 centimeters
Wilmonton--have carbonates within a depth of 100 centimeters
GEOGRAPHIC SETTING:
Parent material--30 to 75 centimeters of loamy sediments and the underlying till
Landform--slightly convex side slopes on dissected till plains of low relief on the Iowan erosion surface
Slope--0 to 5 percent
Elevation--300 to 400 meters above sea level
Mean annual air temperature--7 to 10 degrees C
Mean annual precipitation--735 to 940 millimeters
Frost-free period--160 to 195 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Clyde,
Floyd,
Marquis, and
Tripoli soils.
Clyde--are at lower landscape positions on toe slopes and in drainageways and are frequently saturated at the soil surface during the wettest periods in years when precipitation is within one standard deviation of the 30 year mean of annual precipitation
Floyd--are at lower landscape positions on concave foot slopes and have a clay content of 20 to 30 percent and a sand content of 20 to 40 percent throughout the upper half of the series control section
Marquis--are at higher landscape positions on convex ridges and side slopes and have a frequently saturated zone between depths of 0.6 to 1.0 meter during the wettest periods in years when precipitation is within one standard deviation of the 30 year mean of annual precipitation
Tripoli--are at lower elevations in flat to concave drainageways and are frequently saturated at the soil surface during the wettest periods in 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 to 1.0 meter during April to June in years when precipitation is within one standard deviation of the 30 year mean of annual precipitation, this saturation is considered 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 loamy sediments and 0.01 to 1.0 micrometers per second in the underlying till
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, and other grasses of the tall grass prairie.
DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic section--Dissected till plains
MLRA--Eastern Iowa and Minnesota Till Prairies (104)
Local physiographic area--Iowa Erosion Surface
LRR M; northeastern Iowa and southeastern Minnesota
Extent--large
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Bremer County, Iowa, 1965
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 150 centimeters.
Diagnostic horizons and features recognized in this pedon include:
mollic epipedon--the zone from the surface to a depth of 48 centimeters (A1, A2, and BA horizons);
cambic horizon--the zone from a depth of 48 to 117 centimeters (Bw, 2Bg1 and 2Bg2 horizons);
udic moisture regime.
Aquic subgroup--matrix hue of 10YR and chroma of 2 in the zone from a depth of 48 to 61 centimeters (Bw horizon).
Cation-exchange activity class is supported by laboratory data from NSSL.
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 glacial till.
Taxonomy version--Keys to Soil Taxonomy, tenth edition, 2006.
ADDITIONAL DATA:
Laboratory data--National Soil Survey Laboratory, Lincoln, Nebraska-user pedon id numbers 60IA017002 and 60IA017004, (http://ssldata.sc.egov.usda.gov/);
Soil Survey Investigations Report No. 3; Iowa State University, Ames, Iowa.