LOCATION NIOBRARA NE+WYEstablished Series
TAXONOMIC CLASS: Mixed, mesic, shallow Aridic Ustipsamments
TYPICAL PEDON: Niobrara loamy fine sand with a convex, north facing 25 percent slope in an area of native vegetation. When described, the soil was moist throughout. (Colors are for dry soil unless otherwise stated)
A--0 to 4 inches; light brownish gray (10YR 6/2) loamy fine sand, dark grayish brown (10YR 4/2) moist; weak fine granular structure; soft, very friable; 2 percent by volume sandstone gravel; many very fine and fine and few medium roots; slight effervescence; slightly alkaline; clear smooth boundary. (3 to 7 inches thick)
C--4 to 13 inches; light brownish gray (10YR 6/2) fine sand, grayish brown (10YR 5/2) moist; single grain; loose; 5 percent by volume sandstone gravel; many fine and very fine and few medium roots; strong effervescence; moderately alkaline; abrupt wavy boundary. (5 to 13 inches thick)
Cr--13 to 80 inches; very pale brown (10YR 8/2) fine grained sandstone, light gray (10YR 7/2) moist; cracks with roots spaced more than 4 inches apart; violent effervescence.
TYPE LOCATION: Sheridan County, Nebraska; 7 miles south and 4 miles east of Rushville; 1200 feet north and 2550 feet east of the southwest corner of sec. 33, T. 31 N, R. 43 W. Rushville SE topographic quadrangle; latitude 42 degrees, 37 minutes, 11 seconds North; longitude 102 degrees, 22 minutes, 13 seconds West.
RANGE IN CHARACTERISTICS: Depth to carbonates ranges from 0 to 6 inches. Depth to bedrock ranges from 10 to 20 inches.
The A horizon has hue of 10YR or 2.5Y, value of 4 to 6 dry and 2 to 5 moist, and chroma of 2 or 3. Texture typically is loamy fine sand with the range including fine sandy loam, sandy loam, loamy sand, fine sand or sand. Sandstone gravel ranges from 0 to 10 percent by volume. It is slightly alkaline or moderately alkaline.
Some pedons have an AC horizon.
The C horizon has hue of 10YR, 2.5Y or 5Y value of 5 to 8 dry and 4 to 6 moist and chroma of 2 to 4. Texture is loamy fine sand, loamy sand, fine sand or sand. Sandstone gravel ranges from 5 to 15 percent by volume. It is neutral to moderately alkaline.
The Cr horizon is sandstone bedrock. It is generally calcareous.
COMPETING SERIES: This is the Hozho series. Hozho soils have more than 15 percent rock fragments in the A horizon and occur above elevations of 6500 feet.
GEOGRAPHIC SETTING: Niobrara soils are on hills, ridges, valley sides and interfluves. Slopes range from 0 to 70 percent. Niobrara soils formed in sandy residuum weathered from sandstone with additions of eolian sand in places. The mean annual precipitation ranges from 14 to 18 inches and the mean annual air temperature ranges from 47 to 50 degrees Fahrenheit.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dailey, Orpha and Valent soils. Dailey, Orpha and Valent soils are very deep. Orpha soils are on the lower part of valley sides and footslopes. Dailey and Valent soils are on dunes.
DRAINAGE AND PERMEABILITY: Excessively drained. Runoff is slow to rapid. Permeability is rapid.
USE AND VEGETATION: These soils are used for rangeland. The native vegetation is mainly blue grama, sideoats grama, little bluestem, western wheatgrass, needleandthread and threadleaf sedge.
DISTRIBUTION AND EXTENT: Western Nebraska and eastern Wyoming and possibly southwest South Dakota. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Sheridan County, Nebraska, 1992.
REMARKS: Areas of these soils have previously been included with the Tassel soils.
Diagnostic horizons and features recognized in this pedon are: ochric epipedon - the zone from the surface of the soil to a depth of 4 inches (A horizon); paralithic contact - at a depth of about 13 inches (at the boundary of the C and Cr horizons).