LOCATION HOBBS              NE +KS

HOBBS SERIES

The Hobbs series consists of very deep, well drained soils that formed in stratified, silty alluvium. These soils are on flood plains, foot slopes, and alluvial fans, and have slopes that range from 0 to 6 percent. Mean annual temperature is 11 degrees C (52 degrees F), and mean annual precipitation is 64 centimeters (25 inches) at the type location.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, nonacid, mesic Mollic Ustifluvents

TYPICAL PEDON: Hobbs silt loam with a slope of less than 1 percent in a bluegrass pasture. (Colors are for dry soil unless otherwise stated.)

A--0 to 18 centimeters (0 to 7 inches); grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak medium granular structure; hard, friable; neutral; abrupt smooth boundary. (15 to 51 centimeters) 6 to 20 inches thick)

C1--18 to 86 centimeters (7 to 34 inches); stratified grayish brown (10YR 5/2) and light brownish gray (10YR 6/2) silt loam, very dark grayish brown (10YR 3/2) and dark grayish brown (10YR 4/2) moist; moderate fine and medium granular structure; slightly hard, very friable; neutral; clear smooth boundary. (25 to 76 centimeters) 10 to 30 inches thick)

C2--86 to 112 centimeters (34 to 44 inches); gray (10YR 5/1) silt loam, dark gray (10YR 4/1) moist; moderate, fine and medium granular structure; slightly hard, very friable; neutral; clear smooth boundary. (20 to 31 centimeters) 8 to 12 inches thick)

C3--112 to 152 centimeters (44 to 60 inches); light brownish gray (10YR 6/2) silt loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, friable; neutral.

TYPE LOCATION: Nuckolls County, Nebraska; about 5 miles north and 4 miles west of Superior; 400 feet south and 100 feet east of northwest corner, sec. 32, T. 2 N., R. 7 W.

RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is ustic.
Depth to free calcium carbonate: >40 inches, except some pedons have thin surface layers of recent deposition that contain small amounts of free carbonates.
Mollic epipedon: 15 to 51 centimeters (6 to 20 inches)
Particle-size control section (weighted average): Silt loam
Clay content: 15 to 27 percent
Sand content: 0 to 15 percent

A horizon:
Hue: 10YR
Value: 4 or 5 (dry) 2 or 3 (moist)
Chroma: 1 or 2 (dry or moist)
Texture: silt loam, silty clay loam, very fine sandy loam, or fine sandy loam.
Clay content: 10 to 35 percent
Reaction: slightly acid to moderately alkaline
Note: Thin stratification with material of higher value is apparent in undisturbed areas.

C horizon:
Hue: 10YR or 2.5Y
Value: 4 to 7 (dry) 3 to 6 (moist)
Chroma: 1 to 3 (dry or moist)
Texture: silt loam, but includes layers of silty clay loam and thin strata of slightly coarser or finer textured material.
Clay content: 15 to 30 percent
Reaction: slightly acid to moderately alkaline
Note: It contains thin strata with colors that are within the range or that have slightly higher or lower value. Buried soils are common.

COMPETING SERIES: The Hobbs series is the only member in the family.

GEOGRAPHIC SETTING:
Parent material: noncalcareous, silty sediments derived mostly from soils on adjacent loess mantled uplands.
Landform: flood plains, foot slopes and fans of small streams and drainageways. Some areas are channeled.
Slopes: 0 to 2 percent, but range up to 6 percent
Elevation: 366 to 823 meters (1200 to 2700 feet)
Mean annual temperature: 10 to 12 degrees C (51 to 54 degrees F)
Mean annual precipitation: 46 to 71 centimeters (18 to 28 inches)
Thornthwaites annual PE index: 34 to 54
Frost-free period: 140 to 160 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Coly, Crete, Crofton, Hall, Harney, Hastings, Holder, Holdrege, Hord, Moody, Muir, Nora and Uly soils:
Coly soils on adjacent uplands lack a mollic epipedon and are not stratified.
Crofton soils on adjacent uplands lack a mollic epipedon and are not stratified.
Hall soils on stream terraces have an argillic horizon and a mollic epipedon.
Harney soils on adjacent uplands have an argillic horizon and a mollic epipedon.
Hastings soils on adjacent uplands have an argillic horizon and a mollic epipedon.
Holder soils on adjacent uplands have an argillic horizon and a mollic epipedon.
Holdrege soils on adjacent uplands have an argillic horizon and a mollic epipedon.
Hord soils on stream terraces
Moody soils on adjacent uplands have a mollic epipedon.
Muir soils on stream terraces.
Nora soils on adjacent uplands have a mollic epipedon.
Uly soils on adjacent uplands have a mollic epipedon.
Crete soils on adjacent uplands have an argillic horizon and a mollic epipedon.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage: well
Runoff: low or medium, depending on the slope
Saturated hydraulic conductivity: Moderately high
Flooding: Occasional or frequent, but floodwaters generally recede within a few hours.
Water table: > 6 feet.

USE AND VEGETATION: Where the areas are sufficiently wide and flooding is not too severe, these soils are used for cultivated crops, both dryland and irrigated.
The main crops are corn, grain sorghum, and alfalfa.
The native vegetation species are big bluestem, switchgrass, western wheatgrass, and little bluestem, with scattered deciduous trees.

DISTRIBUTION AND EXTENT: South-central and central Nebraska and north-central Kansas. LRR H, MLRAs 71, 73, 74, 75, 76; LRR M, MLRA 102B. The series is extensive.

MLRA OFFICE RESPONSIBLE: Salina, Kansas

SERIES ESTABLISHED: Saline County, Kansas, 1952.

REMARKS: These soils are previously classified as Cumulic Haplustolls. Phases correlated to date are channeled, seldom flooded, occasionally flooded, overwash, and calcareous.

10/17/05 JCR
Changed to semi-tab format, added metric conversion and changed from permeability to saturated hydraulic conductivity.

Taxonomic Version: Eighth edition, 1998