LOCATION HOBBS                   NE+KS

Established 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 in river valleys of Central Loess Plains, MLRA 75. Slopes range from 0 to 6 percent. Mean annual temperature is 11 degrees C (52 degrees F), and mean annual precipitation is 640 millimeters (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.) As described in 1978.

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.

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.

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 8 kilometers (5 miles) north and 6.4 kilometers (4 miles) west of Superior; 122 meters (400 feet) south and 30 meters (100 feet) east of northwest corner, sec. 32, T. 2 N., R. 7 W. USGS Bostwick, Nebraska quadrangle latitude 40 degrees 6 minutes 10.8 seconds north and longitude 98 degrees 8 minutes and 31.9 seconds west, NAD 83.

Soil moisture: ustic bordering udic.
Soil temperature regime: mesic
Depth to free calcium carbonate: > 100 centimeters (>40 inches), except some pedons have thin surface layers of recent deposition that contain small amounts of free carbonates.
Mollic features: 15 to 24 centimeters (6 to 9 inches)
Particle size control section clay content: 22 to 30 percent
Particle size control section fine sands or coarser content: 0 to 14 percent

A horizon:
Hue: 10YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 1 or 2
Texture: silt loam, silty clay loam, very fine sandy loam, or fine sandy loam.
Clay content: 10 to 35 percent
Sand content: 5 to 70 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
Texture: silt loam, silty clay loam and thin strata of slightly coarser or finer textured material.
Clay content: 12 to 30 percent
Sand content: 0 to 15 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: There are none.

Parent material: alluvium
Landform: flood plains, foot slopes and fans of small streams and drainageways. Some areas are channeled.
Slopes: 0 to 6 percent
Elevation: 366 to 823 meters (1200 to 2700 feet)
Mean annual air temperature: 10 to 13 degrees C (51 to 55 degrees F)
Mean annual precipitation: 460 to 810 millimeters (18 to 32 inches)
Thornthwaites annual PE index: 34 to 54
Frost-free period: 140 to 210 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Crete, Harney, Hastings, Holder, Holdrege, and Uly soils:
Crete, Harney, Hastings, Holder, and Holdrege soils are on adjacent uplands, have an increase of clay in the particle size control section (argillic horizon), and a thicker dark surface (mollic epipedon).
Uly soils on adjacent uplands have a mollic epipedon.

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
Water table: >180 centimeters (> 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, soybeans, 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 Great Plains Winter Wheat and Range, MLRA 71, Central Nebraska Loess Hills, MLRA 73, Rolling Plains and Breaks, MLRA 74 Central Kansas Sandstone, MLRA 75 Central Loess Plains, MLRA 76 Bluestem Hills; LRR M Central Feed Grains and Livestock Region, MLRA 102C Loess Uplands; LRR G Western Great Plains Range and Irrigated Region, MLRA 65 Nebraska Sand Hills. The series is extensive.


SERIES ESTABLISHED: Saline County, Kansas, 1952.

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

The diagnostic horizons and characteristics recognized in this soil are:
Ochric epipedon: 0 to 18 centimeters (0 to 7 inches) (A horizon)

Taxonomic Version: Eleventh edition, 2010

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

7-27-11 JLG
Added quadrangle, latitude, and longitude, added soil temperature regime, particle size control section clay and sand in RIC, added sand content to horizon data in RIC, increased mean annual precipitation to 810 millimeters from 710, increased temperature to 13 degrees C from 12 degrees, and adjusted frost free days based on climate data, updated geographically associated soils. Changed precipitation values from centimeters to millimeters.

Addition laboratory data- National Soil Survey Laboratory, Lincoln, NE pedon S02NE095002.

National Cooperative Soil Survey