LOCATION GIBBON NE+KSEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, calcareous, mesic Fluvaquentic Endoaquolls
TYPICAL PEDON: Gibbon silty clay loam - with a slope of less than 1 percent, in a cultivated field. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 13 centimeters (0 to 5 inches); dark gray (10YR 4/1) silty clay loam, very dark gray (10YR 3/1) moist; moderate very fine granular structure; slightly hard, friable; strong effervescence; moderately alkaline; abrupt smooth boundary.
A--13 to 28 centimeters (5 to 11 inches); very dark gray (10YR 3/1) silty clay loam, black (10YR 2/1) moist; moderate very fine granular structure; slightly hard, friable; strong effervescence; moderately alkaline; clear smooth boundary. (Combined thickness of the A horizon ranges from 25 to 51 centimeters (10 to 20 inches)
AC--28 to 46 centimeters (11 to 18 inches); gray (10YR 6/1) silty clay loam, dark gray (10YR 4/1) moist; moderate very fine granular structure; slightly hard, friable; few fine faint brownish and yellowish iron masses in the matrix; violent effervescence; moderately alkaline; clear smooth boundary. (0 to 25 centimeters (0 to 10 inches) thick)
Cg1--46 to 66 centimeters (18 to 26 inches); light brownish gray (10YR 6/2) silt loam, dark gray (10YR 4/1) moist; massive; soft, very friable; common medium distinct grayish, brownish and yellowish iron masses in the matrix, violent effervescence; moderately alkaline; clear smooth boundary. (15 to 30 centimeters (6 to 12 inches) thick)
Cg2--66 to 91 centimeters (26 to 36 inches); light gray (10YR 7/2) very fine sandy loam, light brownish gray (10YR 6/2) moist; massive; soft, very friable; common coarse prominent brownish iron masses in the matrix; strong effervescence; strongly alkaline; clear smooth boundary. (13 to 38 centimeters (5 to 15 inches) thick)
Cg3--91 to 203 centimeters (36 to 80 inches); light gray (10YR 7/2) fine sandy loam; grayish brown (10YR 5/2) moist; massive; soft, very friable; common coarse prominent brownish iron masses in the matrix; strong effervescence; strongly alkaline.
TYPE LOCATION: Webster County, Nebraska; 1 mile south and 1 1/2 miles west of Inavale; 933 meters (3060 feet) east and 21 meters (70 feet) south of the northwest corner, sec. 9, T. 1 N., R. 12 W.
RANGE IN CHARACTERISTICS:
Soil moisture: moist from December through April and intermittently moist from May through December. The driest months are July through September.
Mean annual soil temperature: 9 to 11 degrees C (48 to 52 degrees F)
Depth to secondary calcium carbonate: 0 to 25 centimeters (0 to 10 inches)
Calcium carbonate equivalent: 5 to 15 percent in the control section.
Depth to redox concentrations: 25 to 51 centimeters (10 to 20 inches)
Depth to episaturation: 30 to 91 centimeters 912 to 36 inches) November to June
Thickness of the mollic epipedon: 25 to 51 centimeters (10 to 20 inches)
Thickness of the solum: 84 to 127 centimeters (33 to 50 inches)
A horizon:
Hue: 10YR or 2.5Y
Value: 3 through 5 dry, 2 or 3 moist
Chroma: 1 or 2
Texture: Typically silt loam or silty clay loam but includes very fine sandy loam, loam, and clay loam.
Clay content: 8 to 35 percent
Sand content: 5 to 85 percent
Reaction: Slightly alkaline or moderately alkaline.
AC and Cg horizons:
Hue: 10YR, 2.5Y or 5Y
Value: 5 through 8 dry, 4 through 6 moist
Chroma: 1 or 2
Texture: Silt loam, clay loam, or silty clay loam.
Carbonate concretions are in the AC and C horizons in some pedons. Below a depth of 102 centimeters (40 inches) the Cg horizon is stratified loamy fine sand, loamy sand, or fine sand in places.
Clay content: 18 to 32 percent
Sand content: 5 to 45 percent
Reaction: Slightly alkaline through strongly alkaline.
COMPETING SERIES: These are the
Colville,
Kittitas,
Pahranagat and
Paranat series in the same family.
Colville soils have a cambic horizon.
Kittitas soils have more than 15 percent exchangeable sodium in the Mollic epipedon.
Pahranagat and Paranat soils have less carbonates throughout the series control section and receive less than 30 centimeters (12 inches) annual precipitation.
GEOGRAPHIC SETTING:
Parent material: Calcareous, stratified, alluvium
Landform: Floodplains
Slopes: 0 to 2 percent
Mean annual temperature: 10 to 12 degrees C (50 to 54 degrees F)
Mean annual precipitation: 51 to 76 centimeters (20 to 30 inches)
Frost-free period: 130 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Humbarger,
Inavale,
McCook,
Munjor,
Ord,
Platte, and
Wann soils.
Humbarger, Inavale, McCook, and Munjor soils have a seasonal high water table at depths below 6 feet.
Inavale soils are sandy.
Munjor soils are coarse-loamy throughout the particle size control section.
Platte soils have coarse sand, gravelly coarse sand or gravelly sand at depths between 25 to 51 centimeters (10 and 20 inches).
Wann and Ord soils are coarse-loamy in the particle size control section.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage: Somewhat poorly drained.
Surface runoff: Low.
Saturated hydraulic conductivity: Moderately low
Flooding: Rarely or occasionally flooded.
Depth to water table: 0 to 1 meter (1 to 3 feet).
USE AND VEGETATION: Most of the area cultivated.
The most common crops are corn, grain sorghum, and alfalfa.
A small acreage is in native grass and a few areas have scattered trees.
DISTRIBUTION AND EXTENT: Central, north-central, and southeastern Nebraska and adjoining areas of northern Kansas. The Gibbon series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Salina, Kansas
SERIES ESTABLISHED: Douglas County, Nebraska, 1970.
REMARKS: Diagnostic horizons and other features recognized in this pedon are: Mollic epipedon: 0 to 28 centimeters (0 to 11 inches) (Ap and A horizon)
Aquic soil conditions: 46 to 203 centimeters (18 to 80 inches) (Cg1, Cg2 and Cg3 horizons).
Phases recognized include saline, saline-alkali, and overwash. These soils generally are not saturated at depths between 38 to 51 centimeters (15 to 20 inches) during the growing season.
10/17/05 JCR
Changed to semi-tab format, added metric conversions and changed from permeability to saturated hydraulic conductivity