LOCATION ADAIR                   IA+MO NE

Established Series
Rev. JAL-RAL-DJP
07/2018

ADAIR SERIES

The Adair series consists of very deep, somewhat poorly drained soils that formed in 25 to 50 centimeters of loess or loess and loamy glacial outwash or erosional sediments and in the underlying paleosol that formed in till. These soils are on interfluves and side slopes on dissected till plains. Slope ranges from 2 to 30 percent. Mean annual air temperature is about 11 degrees C. Mean annual precipitation is about 850 millimeters.

TAXONOMIC CLASS: Fine, smectitic, mesic Aquertic Argiudolls

TYPICAL PEDON: Adair clay loam, on a northwest-facing, convex slope of 7 percent, in a cultivated field, at an elevation of about 373 meters above sea level. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 20 centimeters; very dark grayish brown (10YR 3/2) clay loam, dark grayish brown (10YR 4/2) dry; weak fine granular structure; friable; common fine and very fine roots; common very fine tubular pores; very many distinct black (10YR 2/1) organic stains on faces of peds; moderately acid; clear smooth boundary.

AB--20 to 33 centimeters; dark brown (10YR 3/3) clay loam, grayish brown (10YR 5/2) dry; weak fine subangular blocky structure parting to weak fine granular; friable; common very fine roots; common very fine tubular pores; many distinct very dark grayish brown (10YR 3/2) organic stains on faces of peds; about 2 percent subrounded rock fragments; slightly acid; clear smooth boundary. (0 to 20 centimeters thick)

2Bt1--33 to 51 centimeters; brown (7.5YR 4/4) clay loam; moderate fine prismatic structure parting to moderate fine subangular blocky; firm; common fine and very fine roots; common very fine tubular pores; few fine prominent black (10YR 2/1) manganese masses; common fine distinct yellowish red (5YR 4/6) redoximorphic concentrations; about 5 percent subrounded rock fragments; moderately acid; clear smooth boundary.

2Bt2--51 to 71 centimeters; brown (7.5YR 4/4) clay; moderate fine prismatic structure parting to moderate fine subangular blocky; firm; common fine and very fine roots; common very fine tubular pores; common fine prominent black (10YR 2/1) manganese masses; common fine distinct yellowish red (5YR 4/6) redoximorphic concentrations; about 5 percent subrounded rock fragments; moderately acid; gradual smooth boundary.

2Bt3--71 to 86 centimeters; yellowish brown (10YR 5/4) clay loam; moderate medium prismatic structure parting to moderate fine and medium subangular blocky; firm; common very fine roots; common very fine tubular pores; common fine prominent black (10YR 2/1) manganese masses; many medium distinct yellowish brown (10YR 5/6) redoximorphic concentrations; about 5 percent subrounded rock fragments; slightly acid; gradual smooth boundary.

2Bt4--86 to 130 centimeters; yellowish brown (10YR 5/4) clay loam; moderate medium prismatic structure parting to moderate medium subangular blocky; firm; common very fine roots; common very fine tubular pores; common fine prominent black (10YR 2/1) manganese masses; many medium distinct yellowish brown (10YR 5/6) redoximorphic concentrations; common medium distinct grayish brown (2.5Y 5/2) redoximorphic depletions; about 5 percent subrounded rock fragments; slightly acid; gradual smooth boundary. (Combined thickness of the 2Bt horizon is 60 to 125 centimeters.)

2Bk1--130 to 152 centimeters; yellowish brown (10YR 5/4) clay loam; weak medium prismatic structure parting to weak medium subangular blocky; firm; common very fine roots; common very fine tubular pores; common medium prominent white (10YR 8/1) carbonate masses; common medium prominent black (10YR 2/1) manganese masses; many medium distinct yellowish brown (10YR 5/6) redoximorphic concentrations; common medium distinct grayish brown (2.5Y 5/2) redoximorphic depletions; about 4 percent subrounded rock fragments; slightly effervescent; slightly alkaline; gradual wavy boundary.

2Bk2--152 to 173 centimeters; about 60 percent yellowish brown (10YR 5/4) and about 40 percent yellowish brown (10YR 5/6) clay loam; weak medium prismatic structure parting to weak medium subangular blocky; firm; common very fine tubular pores; common fine prominent white (10YR 8/1) carbonate masses; few fine prominent black (10YR 2/1) manganese masses; common medium distinct grayish brown (2.5Y 5/2) redoximorphic depletions; about 4 percent subrounded rock fragments; strongly effervescent; slightly alkaline; gradual wavy boundary. (Combined thickness of the 2Bk horizon is 0 to 50 centimeters.)

2BCk--173 to 200 centimeters; about 50 percent yellowish brown (10YR 5/6) and about 50 percent yellowish brown (10YR 5/4) clay loam; firm; common very fine tubular pores; common medium prominent white (10YR 8/1) carbonate masses; common fine prominent black (10YR 2/1) manganese masses; about 4 percent subrounded rock fragments; strongly effervescent; slightly alkaline.

TYPE LOCATION: Land Resource Unit (LRU) 108D-Illinois and Iowa Deep Loess and Drift, Western Part; Ringgold County, Iowa; about 2,490 feet east and 1,950 feet south of the northwest corner of sec. 15, T. 70 N., R. 29 W.; USGS Tingley topographic quadrangle; lat 40 degrees 51 minutes 48.4 seconds N. and long 94 degrees 10 minutes 35.9 seconds W., NAD 83.

RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon--25 to 49 centimeters
Depth to carbonates--100 to 150 centimeters
Clay content in the particle-size control section (weighted average)--38 to 46 percent
Sand content in the particle-size control section (weighted average)--15 to 35 percent
Special features--some pedons have a stone line or thin layer, 2 to 13 centimeters thick, of gravelly and sandy materials at the base of the loess or loess and loamy glacial outwash or erosional sediments

Ap or A horizon:
Hue--7.5YR or 10YR
Value--2, 2.5, or 3
Chroma--1 or 2
Texture--clay loam, silty clay loam, loam, or silt loam
Clay content--24 to 40 percent
Sand content--15 to 30 percent
Rock fragment content--2 to 10 percent
Reaction--strongly acid to neutral

AB or BA horizon (when present):
Hue--7.5YR or 10YR
Value--3 or 4
Chroma--2 to 4
Texture--clay loam, loam, or silty clay loam
Clay content--25 to 40 percent
Sand content--15 to 30 percent
Rock fragment content--2 to 10 percent
Reaction--strongly acid to neutral

2Bt horizon:
Hue--2.5YR to 10YR
Value--3 to 5
Chroma--3 to 6
Texture--clay loam, clay, or silty clay
Clay content--38 to 60 percent in upper part; 30 to 38 percent in lower part
Sand content--15 to 35 percent
Rock fragment content--1 to 10 percent
Reaction--strongly acid to neutral

2Btk horizon (when present):
Hue--2.5YR to 10YR
Value--3 to 5
Chroma--3 to 6
Texture--clay loam
Clay content--30 to 38 percent
Sand content--20 to 45 percent
Rock fragment content--1 to 10 percent
Reaction--slightly alkaline or moderately alkaline

2BCk horizon (when present):
Hue--2.5YR to 2.5Y
Value--3 to 5
Chroma--2 to 6
Texture--clay loam
Clay content--30 to 38 percent
Sand content--20 to 45 percent
Rock fragment content--1 to 10 percent
Reaction--slightly acid to moderately alkaline

2C horizon (when present):
Hue--10YR
Value--4 or 5
Chroma--2 to 6
Texture--clay loam
Clay content--30 to 38 percent
Sand content--20 to 45 percent
Rock fragment content--1 to 10 percent
Reaction--slightly acid to slightly alkaline

COMPETING SERIES: These are the Arisburg, Arispe, Chase, Good Thunder, Greenton, Grundy, Lagonda, Lamoni, Mahaska, Macksburg, Martin, Mayberry, Seymour, Shorewood, Tina, and Wymore series.
Arisburg--have a sand content that averages less than 15 percent in the particle-size control section
Arispe--have a sand content that averages less than 15 percent in the particle-size control section
Chase--has a mollic epipedon more than 49 centimeters thick
Good Thunder--have a sand content that averages less than 15 percent in the particle-size control section
Greenton--have shale fragments within the series control section
Grundy--have a sand content that averages less than 15 percent in the particle-size control section
Lagonda--have a sand content of less than 15 percent in the upper part of the series control section
Lamoni--do not have matrix hue redder than 10YR in the argillic horizon
Macksburg--have a sand content that averages less than 15 percent in the particle-size control section
Mahaska--have a sand content that averages less than 15 percent in the particle-size control section
Martin--have a mollic epipedon more than 49 centimeters thick
Mayberry--do not have rock fragments within the series control section
Seymour--have a sand content that averages less than 15 percent in the particle-size control section
Shorewood--have a sand content that averages less than 15 percent in the particle-size control section
Tina--have a sand content that averages less than 15 percent in the particle-size control section
Wymore--have a sand content that averages less than 15 percent in the particle-size control section

GEOGRAPHIC SETTING:
Parent material--25 to 50 centimeters of loess or loess and loamy glacial outwash or erosional sediments and in the underlying paleosol that formed in till
Landform--interfluves and side slopes on dissected till plains
Slope--2 to 30 percent
Elevation--185 to 505 meters above sea level
Mean annual air temperature--8 to 13 degrees C
Mean annual precipitation--660 to 1,040 millimeters
Frost-free period--155 to 215 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Clarinda, Sharpsburg, and Shelby soils.
Clarinda--are at slightly higher landscape positions and have matrix chroma of 2 or less throughout the series control section
Sharpsburg--are at higher landscape positions and have sand content that averages less than 5 percent in the particle-size control section
Shelby--are at lower landscape positions on side slopes and have a clay content that averages less than 35 percent in the particle-size control section

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 the wettest period of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation, this saturation is considered perched
Saturated hydraulic conductivity--0.10 to 10.00 micrometers per second

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, but the underlying paleosol may have formed in a forested environment.

DISTRIBUTION AND EXTENT:
Physiographic location--Interior Plains
Physiographic Province--Central Lowland
Physiographic section--Dissected till plains
MLRAs and LRUs--Nebraska and Kansas Loess-Drift Hills (106); Iowa and Missouri Deep Loess Hills (107B); Illinois and Iowa Deep Loess and Drift (108); and Iowa and Missouri Heavy Till Plain (109)
LRR--M; eastern, western, and southern Iowa, northern Missouri, and southeastern Nebraska
Extent--large

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana.

SERIES ESTABLISHED: Lucas County, Iowa, 1957.

REMARKS:
Diagnostic horizons and features recognized in this pedon include:
Particle-size control section--the zone from a depth of 33 to 83 centimeters.
Series control section--the zone from the surface to a depth of 200 centimeters.
Mollic epipedon--the zone from the surface to a depth of 33 centimeters (Ap and AB horizons).
argillic horizon--the zone from a depth of 33 to 130 centimeters (2Bt1, 2Bt2, 2Bt3, and 2Bt4 horizons).
Udic moisture regime.

Taxonomy version--Keys to Soil Taxonomy, Twelfth Edition, 2014.

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National Cooperative Soil Survey
U.S.A.