LOCATION DARR NE+KSEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Fluventic Haplustolls
TYPICAL PEDON: Darr fine sandy loam-cultivated. (Colors are for dry condition unless otherwise stated.)
Ap--0 to 18 centimeters; gray (10YR 5/1) fine sandy loam, very dark gray (10YR 3/1) moist; weak coarse subangular blocky structure parting to weak fine granular; soft, very friable; neutral; abrupt smooth boundary. (13 to 20 centimeters thick)
A--18 to 36 centimeters; dark gray (10YR 4/1) fine sandy loam, very dark gray (10YR 3/1) moist; weak coarse subangular blocky structure parting to weak fine granular; soft, very friable; neutral; clear smooth boundary. (8 to 30 centimeters thick)
Bw--36 to 64 centimeters; light brownish gray (10YR 6/2) fine sandy loam; grayish brown (10YR 5/2) moist; weak coarse subangular blocky structure parting to weak fine granular; soft, very friable; neutral; clear smooth boundary. (15 to 38 centimeters thick)
2C1--64 to 84 centimeters; light gray (10YR 7/2) fine sand, light brownish gray (10YR 6/2) moist; single grain; few fine and medium distinct yellowish brown (10YR 5/4) moist and dark reddish brown (5YR 3/3) moist redoximorphic concentrations; single grain; loose; neutral; gradual wavy boundary. (15 to 30 centimeters thick)
2C2--84 to 203 centimeters; light gray (10YR 7/2) sand and gravel; light brownish gray (10YR 6/2) moist; single grain; loose; neutral.
TYPE LOCATION: Major Land Resource Area (MLRA) 71-Central Nebraska Loess Hills; Polk County, Nebraska Subset; 750 feet north and 100 feet west of the southeast corner, sec. 24, T. 16 N., R. 2 W. USGS Columbus SW topographic quadrangle; latitude 41 degrees 20 minutes 22 seconds N and longitude 97 degrees 29 minutes 3 seconds W; NAD 83.
RANGE IN CHARACTERISTICS:
Soil moisture: Soil is moist in the A and B horizons from December through April and intermittently moist from May through December. The driest months are July through September.
Depth to secondary carbonates: greater than 150 centimeters.
Depth to redoximorphic features: If present, few fine to medium, distinct yellowish brown iron masses from 64 to 203 centimeters. Some pedons contain medium and coarse, prominent, black depletions of iron-manganese as soft masses at depths of 178 to 203 centimeters.
Thickness mollic epipedon: 25 to 50 centimeters
Combined thickness of A and B horizons: 25 to 70 centimeters
Depth to sand or mixed sand and gravel ranges from 50 to 100 centimeters
Stratification and buried horizons are common above the sand and gravel.
A horizon:
Hue: 10YR
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 1 or 2
Texture: fine sandy loam but ranges to include silt loam and sandy loam.
Reaction: moderately acid to moderately alkaline
A thin AC horizon is present in some pedons.
Bw horizon:
Hue: 10YR or 2.5Y
Value: 6 or 7 dry; 4 through 6 moist
Texture: fine sandy loam, sandy loam, or coarse sandy loam
Reaction: slightly acid to moderately alkaline
2C horizon:
Hue: 10YR or 2.5Y
Value: 6 or 7 dry; 5 or 6 moist
Chroma: 1 or 2
Texture: fine sand through gravelly coarse sand
Rock Fragments: rounded gravel, 2-75 mm in size; 0 to 25 percent gravel by volume
Reaction: neutral to moderately alkaline.
COMPETING SERIES: This is the Cass series. Cass soils lack sand and gravel within a depth of 100 centimeters.
GEOGRAPHIC SETTING:
Parent materials - 50 to 100 centimeters of noncalcareous, stratified, loamy alluvium underlain by layers of sand and mixed sand and gravel
Landform - the flood plains of major streams.
Slope - 0 to 2 percent
Mean annual precipitation - 500 to 720 millimeters
Average annual temperature - 10 to 12 degrees C.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Alda,
Inavale,
Lamo,
Leshara,
Lex,
Ord,
Sarpy, and
Wann soils.
Alda, Lex, Ord, and Wann soils are slightly lower on the landscape and have water saturation at depths of 45 to 90 centimeters. Additionally, Ord and Wann soils lack coarse sand and gravel within depths of 100 centimeters.
Inavale soils are slightly higher on the landscape and are in the sandy particle size class.
Lamo and Leshara soils are slightly lower on the landscape and are in the fine-silty particle size class.
Sarpy soils are slightly higher on the landscape and are in the Psamments suborder.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class in years with normal precipitation, Darr soils lack water saturation to depths of 203 centimeters (somewhat excessively drained).
Runoff - slow.
Saturated hydraulic conductivity - moderately rapid in the alluvium and rapid or very rapid in the sand and gravel.
Darr soils flood rarely for brief periods.
USE AND VEGETATION: Most areas are cropped to winter wheat and grain sorghum. A few areas are in native grass. Some areas are irrigated.
DISTRIBUTION AND EXTENT:
Physiographic Division: Interior Plains
Physiographic Province: Great Plains
Physiographic Section: High Plains
Land Resource Region: Central Great Plains Winter Wheat and Range Region (LRR H)
Major Land Resource Areas: Central Nebraska Loess Hills (MLRA 71) and Great Bend Sand Plains (MLRA 79)
The Darr series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Polk County, Nebraska, 1975.
REMARKS:
The diagnostic horizons and features recognized in the typical pedon are:
Mollic epipedon--0 to 36 centimeters (A horizon)
Cambic horizon--36 to 64 centimeters (Bw horizon)
Irregular decrease in organic carbon content between 25 and 125 centimeters
Soil moisture regime - ustic