LOCATION PAWNEE             NE+KS

PAWNEE SERIES

TAXONOMIC CLASS: Fine, smectitic, mesic Oxyaquic Vertic Argiudolls

TYPICAL PEDON: Pawnee loam in a cultivated field. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 15 centimeters; very dark brown (10YR 2/2) loam, dark grayish brown (10YR 4/2) dry; moderate fine and very fine granular structure; many fine and medium and few coarse roots throughout; common fine tubular pores; slightly hard, friable; moderately acid; abrupt smooth boundary. (10 to 18 centimeters thick)

A--15 to 25 centimeters; very dark brown (10YR 2/2) clay loam, very dark grayish brown (10YR 3/2) dry; moderate medium granular structure; many fine and medium and few coarse roots throughout; common fine tubular pores; slightly hard, friable; moderately acid; clear smooth boundary. (8 to 15 centimeters thick)

BA--25 to 36 centimeters; dark brown (10YR 3/3) clay loam, dark yellowish brown (10YR 3/4) dry; moderate fine and medium blocky structure; hard, friable; common fine and few medium roots throughout; common fine tubular pores; few fine prominent dark reddish brown (5YR 3/4) iron masses; moderately acid; gradual smooth boundary. (0 to 15 centimeters thick)

Bt1--36 to 61 centimeters; dark grayish brown (10YR 4/2) clay, brown (10YR 4/3) dry; moderate medium and coarse blocky structure; extremely hard, very firm; common fine and few medium roots throughout; common fine tubular pores; thin continuous organic coatings on faces of peds; 2 percent gravel by volume; few fine and medium prominent reddish brown (5YR 4/4) iron masses; slightly acid; gradual smooth boundary.

Bt2--61 to 81 centimeters; brown (10YR 4/3) clay, dark yellowish brown (10YR 4/4) dry; weak coarse blocky structure; extremely hard, very firm; few fine and medium roots throughout; few fine tubular pores; thin continuous organic coatings on faces of peds; 2 percent gravel by volume; common medium faint grayish brown (10YR 5/2), strong brown (7.5YR 5/6) and prominent reddish brown (5YR 5/4) iron masses; neutral; gradual smooth boundary.

Bt3--81 to 114 centimeters; olive brown (2.5Y 4/4) clay, light olive brown (2.5Y 5/4) dry; weak coarse blocky structure; very hard, very firm; few fine and medium roots throughout; few fine tubular pores; thin patchy organic coatings on faces of peds; 2 percent gravel by volume; many medium distinct grayish brown (10YR 5/2) and prominent brown (7.5YR 5/4) iron masses; moderately alkaline; gradual smooth boundary. (Combined thickness of the Bt horizons is 56 to 89 centimeters thick)

BC--114 to 135 centimeters; mixed grayish brown (2.5Y 5/2) and yellowish brown (10YR 5/6) clay, light olive brown (2.5Y 5/4) and dark yellowish brown (10YR 4/4) dry; weak medium blocky structure; very hard, very firm; few fine and medium roots throughout; few fine tubular pores; few medium lime concretions; 2 percent gravel by volume; many medium prominent brown (7.5YR 4/4) iron masses; moderately alkaline; clear smooth boundary. (20 to 25 centimeters thick)

C--135 to 203 centimeters; grayish brown (2.5Y 5/2) clay loam, light olive brown (2.5Y 5/4) dry; massive; small iron and manganese concretions; 2 percent gravel by volume; few medium and large soft masses of lime; many coarse distinct grayish brown (10YR 5/2) iron masses; moderately alkaline.

TYPE LOCATION: Pawnee County, Nebraska; about 6 kilometers north of Pawnee City; 483 meters west and 107 meters south of the northeast corner, sec. 2, T. 2 N., R. 11 E. USGS Steinauer topographic quadrangle; latitude 40 degrees 10 minutes 27 seconds North and longitude 96 degrees 8 minutes 5 seconds West, NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture control section: wet March through May
Moisture regime: udic
Mean annual soil temperature: 10 to 13 degrees C. (51 to 56 degrees F.)

Depth to argillic horizon: 18 to 48 centimeters
Depth to secondary calcium carbonate: 74 to 137 centimeters
Depth to redoximorphic concentrations: 18 to 33 centimeters
Depth to episaturation: 30 to 91 centimeters from March to May
Thickness of the mollic epipedon: 25 to 48 centimeters, commonly includes the upper part of the B horizon
Thickness of the solum: 102 to 152 centimeters

Particle-size control section (weighted average):
Clay content: 40 to 48 percent
Sand content: 20 to 45 percent
Rock fragments: 0 to 5 percent by volume
Size: gravel

A horizon:
Hue: 10YR
Value: 2 or 3, 3 to 5 dry
Chroma: 1 or 2
Texture: loam, clay loam or clay
Clay content: 15 to 41 percent
Reaction: moderately acid to neutral
Note: a BA horizon in present in some pedons

Bt horizon:
Hue: 10YR, 2.5Y or 5Y
Value: 3 to 5, 3 to 6 dry
Chroma: 2 to 4
Redoximorphic Concentrations: hue: 7.5YR or 5YR; value: <5; chroma: <6
Texture: clay
Clay content: 40 to 48 percent
Rock fragments: 0 to 5 percent gravel
Reaction: slightly acid to moderately alkaline.
Note: Btss horizons are present in some pedons

BC horizon:
Hue: 10YR or 2.5Y or 5Y
Value: 5 or 6 moist or dry
Chroma: 2 to 6
Redoximorphic Concentrations: hue: 7.5YR or 5YR; value: <5; chroma: <4
Texture: Clay
Clay content: 40 to 48 percent
Rock fragments: 0 to 5 percent gravel
Reaction: slightly alkaline or moderately alkaline

C horizon:
Hue: 10YR or 2.5Y or 5Y
Value: 5, 5 or 6 dry
Chroma: 0 to 4
Redoximorphic Concentrations: hue: 10YR, 7.5YR or 5YR; value: <5; chroma: <4
Texture: clay loam, but the range includes sandy clay loam or loam.
Clay content: 15 to 40 percent
Rock fragments: 0 to 5 percent by volume
Reaction: slightly alkaline or moderately alkaline

COMPETING SERIES: These are the Adair, Baileyville, Chillicothe and Cornell soils.
Adair soils have carbonates at 102 to 152 centimeters, have a clay content of 38 to 46 percent and a sand content of 15 to 35 percent in the control section.
Baileyville and Chillicothe soils have less than 10 percent sand.
Cornell soils have a lithologic discontinuity within the series control section.

GEOGRAPHIC SETTING:
Parent material: Till
Landform: Uplands
Slopes: 0 to 12 percent
Mean annual temperature: 11 to 13 degrees C. (51 to 56 degrees F.)
Mean annual precipitation: 64 to 86 centimeters
Frost-free period: 160 to 180 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aksarben, Arisburg, Burchard, Crete, Mayberry, Morrill, Shelby, Steinauer and Wymore soils.
Aksarben, Arisburg, Crete, and Wymore soils formed in loess and are typically at higher elevations on the landscape.
Mayberry and Morrill soils have a redder hue and are typically on side slopes at lower elevations.
Shelby, Steinauer and Burchard soils formed in till and have fine-loamy control sections.
In addition, Steinauer soils lack argillic horizons and are calcareous.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage: moderately well drained
Runoff: medium or rapid runoff
Saturated Hydraulic Conductivity: moderately low to low.
Seasonal high water saturation: common 30 to 91 centimeters in the spring.

USE AND VEGETATION: Most of the acreage is cropland.
A small acreage is irrigated and wheat, sorghum, and tame grass pasture are grown.
Native vegetation was mostly tall and mid grasses.

DISTRIBUTION AND EXTENT: Southeast Nebraska and northeast Kansas; LRR M, MLRA 106; Extensive extent.

MLRA OFFICE RESPONSIBLE: Salina, Kansas

SERIES ESTABLISHED: Pawnee County, Nebraska, 1920.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: 36 to 114 centimeters (All Bt horizons)
Mollic epipedon: 0 to 36 centimeters (Ap, A and BA horizons)
Argillic horizon: 36 to 114 centimeters (Bt1, Bt2, Bt3 horizons)
Redoximorphic concentrations: 25 centimeters on down. (BA, Bt, BC, and C horizons)
Vertic features: 35 percent or more clay at 36 to 114 centimeters (Bt horizons)
Episaturation: 30 to 91 centimeters (Bt horizons)

LRR=H

Modified format by LRM in 7/2006 to include metric conversion and change permeability to saturated hydraulic conductivity.

GJ 5/15/2008 Removed English units, updated competing series, defined mean annual temperature as mean annual air temperature and removed the term glacial from till.