LOCATION KONZA              KS

KONZA SERIES

The Konza series consists of deep and very deep, moderately well drained, very slowly permeable soils that formed in loess over a paleosol on uplands. These nearly level to gently sloping soils are on ridgetops and upper side slopes in the Bluestem Hills. Slopes range form 0 to 3 percent. The mean annual precipitation is 33 inches, and the mean annual air temperature is 55 degrees F.

TAXONOMIC CLASS: Fine, smectitic, mesic Udertic Paleustolls

TYPICAL PEDON: Konza silty clay loam - rangeland (Color is for dry soil unless otherwise stated.)

A--0 to 6 inches; very dark gray (10YR 3/1) silty clay loam, black (10YR 2/1) moist; moderate medium granular structure; soft, very friable, sticky and plastic; many fine roots throughout; very few distinct dark gray (10YR 4/1) discontinuous skeletans (sand or silt) on faces of peds; slightly acid; clear smooth boundary. (Thickness ranges from 3 to 8 inches.)

Bt1--6 to 17 inches; dark grayish brown (10YR 4/2) silty clay, very dark brown (10YR 2/2) moist; weak medium columnar structure parting to strong fine and medium angular blocky; very hard, very firm, very sticky and very plastic; common fine roots between peds; common distinct very dark brown (10YR 2/2) continuous clay films (cutans) on vertical and horizontal faces of peds, and few black (10YR 2/1) faint organic coats on vertical faces of peds; moderately acid; gradual smooth boundary.

Bt2--17 to 28 inches; dark grayish brown (10YR 4/2) silty clay, very dark grayish brown (10YR 3/2) moist; moderate medium and coarse subangular blocky structure; very hard, very firm, very sticky and very plastic; common fine roots between peds; many distinct very dark brown (10YR 2/2) continuous clay films (cutans) on vertical and horizontal faces of peds, and few black (10YR 2/1) patchy organic coats on vertical faces of peds; neutral; clear smooth boundary.

Btk1--28 to 34 inches; brown (10YR 5/3) silty clay, brown (10YR 4/3) moist; moderate fine and medium subangular blocky structure; very hard, firm, very sticky, and very plastic; few very fine roots between peds; common distinct very dark grayish brown (10YR 3/2) continuous clay films (cutans) on vertical and horizontal faces of peds, and very few very dark brown (10YR 2/2) faint organic coats on vertical faces of peds; few fine rounded carbonate concretions; sodium adsorption ratio of 7; slightly alkaline; clear smooth boundary.

Btk2--34 to 42 inches; mixed brown (10YR 5/3) and grayish brown (10YR 5/2) silty clay loam; mixed brown (10YR 4/3) and dark grayish brown (10YR 4/2) moist; common fine distinct dark yellowish brown (10YR 4/6) mottles; moderate medium subangular blocky structure; hard, firm, very sticky and very plastic; few very fine roots throughout; few distinct dark brown (10YR 3/3) faint clay films (cutans) on vertical faces of peds; common fine and medium rounded carbonate concretions; sodium adsorption ratio of 8; moderately alkaline; clear smooth boundary.

Bt3--42 to 50 inches; mixed grayish brown (10YR 5/2) and light brownish gray (10YR 6/2) silty clay loam; mixed dark grayish brown (10YR 4/2) and grayish brown (10YR 5/2) moist; common fine and medium prominent dark yellowish brown (10YR 4/6) mottles; weak fine and medium subangular blocky structure; hard, friable, sticky and plastic; few very fine roots throughout; very few prominent dark grayish brown (10YR 4/2) faint clay films (cutans) on vertical and horizontal faces of peds; sodium adsorption ratio of 8; moderately alkaline; clear smooth boundary. (Combined thickness of the Bt horizons range from 26 to 57 inches.)

2Bt1--50 to 62 inches; mixed brown (7.5YR 4/4) and grayish brown (10YR 5/2) silty clay loam, mixed dark brown (7.5YR 3/4) and dark grayish brown (10YR 4/2) moist; moderate fine and medium subangular blocky structure; hard, firm, sticky and plastic; few distinct dark brown (7.5YR 3/4) faint clay films (cutans) on vertical faces of peds, and very few manganese or iron-manganese stains on faces of peds; sodium adsorption ratio of 8; neutral; gradual smooth boundary.

2Bt2--62 to 70 inches; mixed brown (7.5YR 4/4) and reddish brown (5YR 4/3) silty clay; mixed dark brown (7.5YR 3/4) and dark reddish brown (5YR 3/3) moist; moderate fine and medium subangular blocky structure; very hard, very firm, very sticky and very plastic; common distinct dark reddish brown (5YR 3/3) continuous clay films (cutans) on vertical and horizontal faces of peds, and faint manganese or iron-manganese stains on faces of peds; sodium adsorption ratio of 8; 1 percent gravel, mostly chert and limestone pebbles; slightly alkaline; clear smooth boundary.

2Bt3--70 to 80 inches; reddish brown (5YR 4/3) silty clay; dark reddish brown (5YR 3/3) moist; strong fine and medium angular blocky structure; very hard, very firm, very sticky and very plastic; common distinct dark reddish brown (5YR 3/3) continuous clay films (cutans) on vertical and horizontal faces of peds, and common faint manganese or iron-manganese stains on faces of peds; sodium adsorption ratio 7; 1 percent gravel, mostly chert and limestone pebbles; slightly alkaline.

TYPE LOCATION: Geary County, Kansas; about 13.5 miles south and 4 miles west of Manhattan; 800 feet south and 200 feet east of the northwest corner of section 25 T. 12 S., R. 7 E. USGS White City NE, Kansas topographic quadrangle; latitude 38 degrees, 59 minutes, 4 seconds, longitude 96 degrees, 36 minutes, 46 seconds.

RANGE IN CHARACTERISTICS:
Mollic epipedon: 20 to 36 inches
Depth to the discontinuity: 35 to 60 inches
Depth to bedrock: 60 to 100 inches.

A horizon:
Hue: 10YR
Value: 3 or 4, 2 or 3 moist
Chroma of 1 or 2.
Texture: silt loam or silty clay loam
Reaction: moderately acid to neutral.

Bt horizon:
Hue: 10YR
Value: 4 to 6, and 2 to 5 moist
Chroma of 2 to 4
Texture: silty clay, clay, or silty clay loam ranging from 35 to 55 percent clay.
Reaction: moderately acid to neutral in the upper part and slightly acid to moderately alkaline in the lower part.
Sodium Adsorption Ratio: ranges from 2 to 12.

2Bt horizons:
Hue: 7.5YR to 5YR
Value: 4 to 6 and 3 to 5 moist
Chroma of 2 to 4
Texture: silty clay loam or silty clay
Reaction: neutral to moderately alkaline
Sodium Adsorption Ratio ranges from 4 to 15.

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: The Konza soils are on upland divides. This soil formed in loess over a clayey paleosol. The slope gradient ranges from 0 to 3 percent. The mean annual air temperature ranges from 54 to 57 degrees F, and the mean annual precipitation ranges from 30 to 33 inches. Thornthwaites Annual P-E Index ranges from 48 to 64.

GEOGRAPHICALLY ASSOCIATED SOILS: These are Benfield, Clime, Florence, Irwin, and Ladysmith soils. Benfield and Clime soils have shale at depths less than 40 inches and are on slopes below the Konza soils. The Florence soils are clayey-skeletal and are on slopes below the Konza soils. Irwin and Ladysmith soils are on similar topographic positions as Konza soils. Irwin soils are greater than 8 inches to horizons containing more than 40 percent clay. Ladysmith soils have sodium adsorption ratio less than 2 throughout.

DRAINAGE AND PERMEABILITY: Moderately well drained. Permeability is very slow and runoff is high to very high.

USE AND VEGETATION: About half is cultivated; wheat and sorghum are the principal crops. The remainder is used as rangeland. Native vegetation is mixed prairie.

DISTRIBUTION AND EXTENT: Mostly in the Bluestem Hills, LRR H; MLRA 76 of east central Kansas. The series is of moderate extent.

MLRA OFFICE RESPONSIBLE: Salina, Kansas

SERIES ESTABLISHED: Geary County, Kansas, 1991. The name is from the nearby Konza Prairie Research Natural Area.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon, the zone from the surface of the soil to a depth of about 28 inches (A, Bt1, and Bt2 horizons); and argillic horizon - the zone from approximately 6 to 80 inches (Bt horizons). These soils were formerly mapped as Dwight and Irwin soils. Dwight soils have a natric horizon, the Konza soils do not. Irwin soils have a surface layer greater than 8 inches thick.
06/2003 Horizon nomenclature corrected the "b" was removed as these soils have a welded paleosol and not a buried soil.

ADDITIONAL DATA: Analysis from the type location was made by the National Soil Survey Laboratory. Sample numbers 90P2873 to 90P2882 (pedon 90KS061001) at teh following site:
http://ssldata.sc.egov.usda.gov/rptExecute.asp?p=16824&r=1&submit1=Get+Report

Analysis from two additional pedons are also available, sample numbers 91P6658-6660 and 87P2343-2351.