LOCATION PLANO                   IL+IA IN WI

Established Series
Rev. JDA-JCD-AAC
02/2011

PLANO SERIES

The Plano series consists of very deep, well drained soils on outwash plains, stream terraces, or till plains. These soils formed in loess or other silty material and in the underlying loamy stratified outwash or sandy loam till. Slope ranges from 0 to 12 percent. The mean annual air temperature is about 8.9 degrees C (48 degrees F), and the mean annual precipitation is about 914 mm (36 inches).

TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Typic Argiudolls

TYPICAL PEDON: Plano silt loam on a nearly level slope in a cultivated field at an elevation of about 218 meters (715 feet)above mean sea level. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 23 cm (0 to 9 inches); very dark brown (10YR 2/2) silt loam, grayish brown (10YR 5/2) dry; moderate fine granular structure; friable; few very fine roots; slightly acid; clear smooth boundary.

A--23 to 36 cm (9 to 14 inches); dark brown (10YR 3/3) silt loam, brown (10YR 5/3) dry; moderate fine granular structure; friable; many very fine roots; slightly acid; clear smooth boundary. [Combined thickness of the A horizons is 25 to 51 cm (10 to 20 inches).]

Bt1--36 to 48 cm (14 to 19 inches); dark yellowish brown (10YR 4/4) silty clay loam; moderate fine subangular blocky structure; friable; common very fine roots; many distinct dark brown (10YR 3/3) organo-clay films on faces of peds; slightly acid; clear smooth boundary.

Bt2--48 to 79 cm (19 to 31 inches); dark yellowish brown (10YR 4/4) silty clay loam; moderate medium subangular blocky structure; friable; common very fine roots; many distinct brown (10YR 4/3) clay films on faces of peds; slightly acid; clear smooth boundary.

Bt3--79 to 109 cm (31 to 43 inches); dark yellowish brown (10YR 4/4) silty clay loam; moderate medium prismatic structure parting to moderate medium subangular blocky; friable; few very fine roots; many distinct brown (10YR 4/3) clay films on faces of peds; common distinct very pale brown (10YR 7/3) (dry) silt coatings on faces of peds; few fine faint yellowish brown (10YR 5/4) iron-manganese accumulations in the matrix; slightly acid; clear smooth boundary.

Bt4--109 to 124 cm (43 to 49 inches); dark yellowish brown (10YR 4/4) silt loam; moderate medium prismatic structure; friable; few very fine roots; many distinct brown (10YR 4/3) clay films on faces of peds; few distinct very pale brown (10YR 7/3) (dry) silt coatings on faces of peds; slightly acid; clear smooth boundary. [Combined thickness of the Bt horizons is 51 to 89 cm (20 to 35 inches).]

2Bt5--124 to 135 cm (49 to 53 inches); dark yellowish brown (10YR 4/4) clay loam; weak medium prismatic structure; friable; few fine roots; many distinct brown (10YR 4/3) clay films on faces of peds; neutral; clear smooth boundary. [15 to 51 cm (6 to 20 inches) thick]

2BC--135 to 152 cm (53 to 60 inches); brown (7.5YR 4/4) sandy loam; weak medium subangular blocky structure; very friable; many distinct dark yellowish brown (10YR 3/4) clay bridging between sand grains; 5 percent gravel; neutral; gradual smooth boundary. [0 to 25 cm (0 to 10 inches) thick]

2C--152 to 183 cm (60 to 72 inches); stratified yellowish brown (10YR 5/6) and brown (7.5YR 4/4) sandy loam, loam, and loamy sand; massive; friable; 12 percent gravel; neutral.

TYPE LOCATION: Stark County, Illinois; Valley township; 1,200 feet south and 1,920 feet east of the northwest corner of sec. 13, T. 12 N., R. 7 E.; USGS Castleton, IL topographic quadrangle; lat. 41 degrees, 01 minute, 45 seconds, N. and long. 89 degrees, 39 minutes, 00 seconds W.; NAD 27; UTM Zone 16, easting 0277210, northing 4545382, NAD 83.

RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon: 25 to 51 cm (10 to 20 inches)
Depth to the base of the argillic horizon: 112 to 178 cm (44 to 70 inches)
Depth to horizons with more than 10 percent sand: 102 to 152 cm (40 to 60 inches)
Depth to carbonates: greater than 183 cm (72 inches) in the solum
Particle-size control section: averages 27 to 35 percent clay and less than 10 percent sand

Ap or A horizon;
Hue: 10YR
Value: 2 or 3 moist, 4 or 5 dry
Chroma; 1 to 3 moist or dry
Texture: silt loam
Clay content: 18 to 27 percent
Reaction: slightly acid or neutral

AB or BA horizon:
Hue: 10YR
Value; 3 or 4 moist, 5 or 6 dry
Chroma: 2 to 4 moist or dry
Texture: silt loam or silty clay loam
Reaction: moderately acid to neutral

The upper part of the Bt horizon:
Hue: 10YR
Value; 4 or 5
Chroma; 3 or 4
Texture: silt loam or silty clay loam
Clay content; 20 and 35 percent
Reaction: typically moderately acid but ranges from strongly acid to neutral.

The lower part of the Bt horizon:
Hue: 7.5YR or 10YR
Value: 3 to 5
Chroma: 2 to 4
Texture: silt loam or silty clay loam
Average clay content: 25 to 30 percent, individual subhorizons range from 20 to 33 percent clay.
Other features: some pedons have iron depletions or clay films with chroma of 1 or 2
Reaction: moderately acid to neutral

2Bt or 2BC horizon:
hue: 7.5YR or 10YR
Value; 3 to 5
Chroma: 2 to 6
Texture: silt loam, loam, sandy loam, clay loam or sandy clay loam
Average clay content: 15 to 32 percent, individual subhorizons or strata range from 5 to 35 percent clay
Average sand content; 20 to 60 percent, individual subhorizons or strata range from 20 to 90 percent sand
average volume of rock fragments: between 2 to 15 percent, individula subhorizons or stata range from 2 to 25 percent gravel
Reaction: moderately acid to slightly alkaline

2C horizon:
Hue: 7.5YR, 10YR or 2.5Y
Value: 3 to 5
Chroma: 3 to 6
Texture: loam, loamy sand, sandy loam, or silt loam, and typically is stratified.
Average content of clay: 5 to 20 percent
Average content of sand: 25 to 80 percent
Average volume of rock fragments: between 3 and 25 percent
Reaction: moderately acid to moderately alkaline
Other features: some pedons have redoximorphic features with value of 5 or 6 and chroma of 2 to 6.

COMPETING SERIES: These are the Ashdale, Broadwell, Dinsdale, Douglas, Elkhart, Elmont, Healing, Lycurgus, Malcolm, Meadowbank, Mendota, Mickle, Ogle, Osco, Parkway, Proctor, Richwood, Ripon, Sibley, Sidell, Tama, Tecumseh, Toddville, Wakenda, and Waupecan series. Ashdale, Elmont, and Ripon soils have sola terminated by bedrock within a depth of 152 cm (60 inches). Broadwell, Richwood, and Toddville soils have in the lowest one-quarter of the series control section an average sand content of greater than 80 percent. Dinsdale, Lycurgus, Meadowbank, Mendota, Proctor, Sidell, Tecumseh, and Waupecan soils have horizons with more than 10 percent sand within a depth of 102 cm (40 inches). Douglas and Parkway soils have in the lowest one-quarter of the series control section a narrower range in sand content with no subhorizon exceeding 45 percent sand nor exceeding 15 percent gravel. Elkhart, Osco, Tama, and Wakenda soils have in the lowest one-quarter of the series control section an average sand content of less than 25 percent. Healing soils average more than 1 percent coarse fragments of chert in the upper part of the series control section. Malcolm soils have the base of the argillic horizon within a depth of 112 cm (44 inches). Mickle soils average 18 to 30 percent clay in the particle-size control section. Ogle soils have hue of 5YR or redder in the lower part of the series control section. Sibley soils have mollic epipedons greater than 51 cm (20 inches) thick.

GEOGRAPHIC SETTING: Plano soils are on outwash plains or stream terraces. Slope gradients commonly are 0 to 5 percent but some are as steep as 12 percent. The soils formed in 102 to 152 cm (40 to 60 inches) of loess or other silty material and the underlying loamy stratified outwash or sandy loam till. The mean annual air temperature ranges from 7.8 to 12.2 degrees C (46 to 54 degrees F), mean annual precipitation ranges from 740 to 990 mm (29 to 39 inches), frost-free period ranges from 160 to 180 days, and elevation ranges from 207 to 311 meters (680 to 1020 feet) above mean sea level.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Proctor soils and the Brenton, Catlin, Dana, Drummer, Elburn, and Thorp soils. The moderately well drained Catlin and Dana soils are on adjacent moraines. Proctor soils are on similar nearby parts of the landscape where the mantle of loess is thinner. The somewhat poorly drained Brenton and Elburn soils and the poorly drained Drummer and Thorp soils are on lower parts of the landscape. Elburn and Drummer soils form a drainage sequence with Plano soils in areas underlain by loamy outwash.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Plano soils are well drained. The potential for surface runoff is low or medium. Saturated hydraulic conductivity is moderately high to high (4.23 to 14.11 micrometers per second) in the solum and moderately high and high (4.23 to 42.34 micrometers per second) in the underlying material. Permeability is moderate in the solum and moderate to moderately rapid in the underlying material. Very rarely flooded or rarely flooded phases of these soils that occur on stream terraces are recognized.

USE AND VEGETATION: Most areas of Plano soils are cultivated. Corn and soybeans are the principal crops. Native vegetation is prairie grasses.

DISTRIBUTION AND EXTENT: Illinois, Wisconsin, Iowa, and Indiana. LRRs K and M, MLRAs 95B, 104, 108A, 108B, 108C, 110, and 115C. The extent is large; more than 426,000 acres have been correlated to date, the majority of which is in MLRA 108A, 108B, and 108C.

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

SERIES ESTABLISHED: Kendall County, Illinois, 1941.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
mollic epipedon -- from the a depth of 0 to 36 cm (0 to 14 inches) (Ap and A horizons)
argillic horizon -- from 36 to 135 cm (14 to 53 inches) (Bt1, Bt2, Bt3, Bt4, and 2Bt5 horizons)
lithologic discontinuity from loess to outwash at a depth of 124 cm (49 inches)

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National Cooperative Soil Survey
U.S.A.