LOCATION BENFIELD KS+NEEstablished Series
The Benfield series consists of moderately deep, well drained, slowly permeable soils that formed in clayey pedisediment over clayey residuum weathered from alkaline shales. These soils are on uplands. Slopes range from 3 to 35 percent. Mean annual temperature is about 55 degrees F, and mean annual precipitation is about 30 inches.
TAXONOMIC CLASS: Fine, mixed, superactive, mesic Udertic Argiustolls
TYPICAL PEDON: Benfield silty clay loam - in native range. (Colors are for dry soil unless otherwise stated.)
A1--0 to 6 inches, (0 to 15 cm); black (10YR 2/1) exterior, gravelly silty clay loam, very dark gray (10YR 3/1) exterior, dry; moderate medium granular structure; friable, hard; many fine roots throughout; 20 percent subangular 20 to 75 millimeter cherty limestone fragments; noneffervescent; clear wavy boundary.
A2--6 to 12 inches, (15 to 30 cm); very dark brown (10YR 2/2) exterior, gravelly silty clay loam, very dark grayish brown (10YR 3/2) exterior, dry; moderate very fine and fine subangular blocky structure; firm; many fine roots throughout; 5 percent subangular 75 to 250 millimeter cherty limestone fragments and 20 percent subangular 20 to 75 millimeter cherty limestone fragments; noneffervescent; clear wavy boundary.
2Bt1--12 to 20 inches, (30 to 51 cm); very dark brown (7.5YR 2/3) exterior and dark brown (7.5YR 3/3) crushed, silty clay; moderate fine subangular blocky structure; very firm; common fine roots throughout; 15 percent patchy distinct very dark brown (7.5YR 2/3), moist, clay films on faces of peds; 5 percent subangular 2 to 75 millimeter cherty limestone fragments; noneffervescent; gradual wavy boundary.
2Bt2--20 to 26 inches, (51 to 66 cm); reddish brown (5YR 4/3) crushed and dark reddish brown (5YR 3/3) exterior, silty clay; moderate medium subangular blocky structure; very firm; common fine roots throughout; 15 percent patchy distinct dark brown (7.5YR 3/2), moist, clay films on faces of peds; strong effervescence; clear wavy boundary.
2Btk--26 to 33 inches, (66 to 85 cm); dark reddish gray (5YR 4/2) exterior, silty clay; weak medium subangular blocky structure; firm; common fine roots throughout; 5 percent patchy distinct dark brown (7.5YR 3/3), moist, clay films on faces of peds; 5 percent fine spherical carbonate nodules between peds; strong effervescence; abrupt wavy boundary.
3BCk--33 to 39 inches, (85 to 99 cm); olive (5Y 5/4) exterior, very paragravelly silty clay loam; weak fine subangular blocky structure; firm; 10 percent fine irregular carbonate nodules between peds; 60 percent rounded 2 to 75 millimeter shale fragments; violent effervescence; clear wavy boundary.
3Cr--39 to 44 inches, (99 to 112 cm); weathered, calcareous, olive colored shale.
TYPE LOCATION: Riley County, Kansas; about 3 miles west and 3 1/2 miles north of Manhattan; 1,530 feet east and 40 feet north of the southwest corner, sec.
27, T. 9 S., R. 7 E.; USGS Keats, Kansas topographic quadrangle; UTM Grid Zone 14S, 703795 easting, 4345080 northing, NAD27.
RANGE IN CHARACTERISTICS:
Depth to paralithic contact: 20 to 40 inches.
Thickness of the mollic epipedon: 7 to 20 inches to shale.
Rock fragments: 0 to 30 percent from 2 mm to 3 inches in diameter with fewer coarse fragments ranging from 3 to 10 inches in diameter.
A horizon:
Hue: of 7.5YR, 10YR, or 2.5Y
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 1 or 2 dry or moist
Texture: gravelly silty clay loam, silt loam, or silty clay loam
Clay content: 25 to 35 percent
Reaction: slightly acid to slightly alkaline
2Bt horizon:
Hue: 5YR, to 10YR
Value: 4 to 6 dry, 3 to 5 moist
Chroma of 2 to 6 dry or moist
Texture: silty clay, silty clay loam, clay or their gravelly counterparts, and Clay content: 35 to 60 percent
Reaction: neutral to moderately alkaline
3BC horizon:
Hue: 5YR to 5Y
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 2 to 4 dry or moist
Texture: silty clay loam, clay, or silty clay, or their paragravelly counterparts.
Reaction: slightly alkaline or moderately alkaline
COMPETING SERIES: These are the Blazefork, Ladysmith, Penalosa, and Taver series. Blazefork soils formed in alluvium on floodplains. Penalosa and Taver formed in old alluvium on paleo-terraces. Ladysmith soils are very deep and somewhat poorly drained.
GEOGRAPHIC SETTING: Benfield soils are on uplands. The slope gradient commonly is 8 to 15 percent, but the range is 3 to 35 percent. The soils formed in clayey pedisediments over clayey residuum weathered from varicolored, calcareous shales, mostly of Permian age. The mean annual temperature ranges from 50 to 58 degrees F, and the mean annual precipitation ranges from 26 to 34 inches. Thornthwaites Annual PE Index ranges from 46 to 56.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Clime, Florence, Irwin, Kipson, Labette, Sogn, and Tully soils. Clime soils do not have an argillic horizon. They are on similar topographic positions as Benfield soils. The deep, clayey-skeletal Florence soils are generally above or below areas of Benfield soils. The shallow Kipson and Sogn soils are on similar topographic positions as Benfield soils. Labette and Irwin soils are less sloping and are usually on higher topographic positions. The Irwin soils have mollic epipedons more than 20 inches thick. The deep Tully soils are below areas of Benfield soils.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is high to very high. Permeability is slow.
USE AND VEGETATION: Most areas are used for rangeland with some gentler slopes cultivated to wheat or grain sorghum. Native vegetation is tall prairie grasses.
DISTRIBUTION AND EXTENT: Dominantly in the Bluestem Hills, LRR H; MLRA 76 of Kansas with minor areas in southern Nebraska and central Kansas.
MLRA OFFICE RESPONSIBLE: Salina, Kansas
SERIES ESTABLISHED: Saline County, Kansas, 1952.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon the zone from 0 to 20 inches (A1, A2, and Bt1 horizons)
Argillic horizon the zone from 12 to 33 inches (2Bt1, 2Bt2, and 2Btk horizons)
Paralithic contact: the contact with shale at 39 inches
Lithologic discontinuity: at the upper boundary of the 2Bt horizon
02/2003 The type location was redescribed in March 2000. Classification changed from udic argiustolls to udertic argiustolls based on laboratory samples.
ADDITIONAL DATA:
NSSL Laboratory sample 89KS061043; Kansas State University Soil Characterization Laboratory samples 559-563 (pedon 97KS161049); and 1761-1765 (pedon 99KS161007).