LOCATION BLACKLOUP NEEstablished Series
TAXONOMIC CLASS: Sandy, mixed, mesic Fluvaquentic Endoaquolls
TYPICAL PEDON: Blackloup loam with a slope of less than 1 percent in native hayland (Colors are for dry soil unless otherwise noted). When described on May 28, 2003 the soil was moist from 0 to 20 inches and wet from 20 to 80 inches.
A1--0 to 4 inches, (0 to 10 cm); black (10YR 2/1) crushed, loam, dark gray (10YR 4/1) crushed, dry; strong medium granular structure; very friable, soft; many fine roots throughout and common medium roots throughout and many very fine roots throughout; strong effervescence; moderately alkaline, pH 8.2 by pH meter 1:1 water; clear smooth boundary. Partially decomposed organic layer (10YR 5/2, 10YR 2/2 moist) on surface, 0-3 cm thick.
A2--4 to 8 inches, (10 to 20 cm); black (10YR 2/1) crushed, loam, very dark gray (10YR 3/1) crushed, dry; weak medium subangular blocky parting to moderate medium granular structure; very friable, slightly hard; many fine roots throughout and common medium roots throughout and many very fine roots throughout; slight effervescence; slightly alkaline, pH 7.5 by pH meter 1:1 water; clear smooth boundary.
AC--8 to 13 inches, (20 to 32 cm); black (10YR 2/1) crushed, fine sandy loam, dark gray (10YR 4/1) crushed, dry; weak coarse subangular blocky parting to weak fine granular structure; very friable, soft; common fine roots throughout and few medium roots throughout and common very fine roots throughout; 5 percent fine prominent threadlike brown (7.5YR 4/4), moist, masses of oxidized iron with clear boundaries lining pores; noneffervescent; slightly alkaline, pH 7.5 by pH meter 1:1 water; clear wavy boundary.
Cg--13 to 28 inches, (32 to 71 cm); dark grayish brown (10YR 4/2) crushed, fine sand, light brownish gray (10YR 6/2) crushed, dry; single grain; loose, loose; few fine roots throughout and few very fine roots throughout; 5 percent fine distinct threadlike dark yellowish brown (10YR 4/4), moist, masses of oxidized iron with diffuse boundaries lining pores and concentrated in the upper 5 cm of the horizon; noneffervescent; neutral, pH 7.3 by pH meter 1:1 water; abrupt smooth boundary.
2Ab--28 to 31 inches, (71 to 78 cm); black (2.5Y 2.5/1) crushed, loam, grayish brown (2.5Y 5/2) crushed, dry; massive; very friable, soft; few very fine roots throughout; noneffervescent; slightly alkaline, pH 7.4 by pH meter 1:1 water; abrupt wavy boundary.
3Cg--31 to 80 inches, (78 to 203 cm); gray (2.5Y 5/1) crushed, stratified fine sand, gray (2.5Y 6/1) crushed, dry; single grain; loose, loose; 1 percent rounded indurated 2 to 10 millimeter quartzite fragments; noneffervescent; slightly alkaline, pH 7.5 by pH meter 1:1 water; thin strata of loam (2.5Y 3/1 moist) at 132-137cm and fine sandy loam (2.5Y 3/1 moist) at 150-155cm.
TYPE LOCATION: Holt County, Nebraska; about 2.5 miles southeast of Inman, Nebraska on the north side of U.S. Highway 20/275 and along the south side of the Elkhorn River; 2000 feet west and 1700 feet north of the southeast corner of sec. 33, T. 28 N., R.10 W. Ewing SW topographic quadrangle, latitude 42 degrees, 21 minutes, 18.4 seconds North; longitude 98 degrees, 29 minutes, 00.9 seconds West.
RANGE IN CHARACTERISTICS:
Soil moisture: aquic moisture regime
Mean annual soil temperature: 46 to 55 degrees F
Depth to calcium carbonate: 0 to 23 inches, when present, some pedons have none
Depth to endosaturation: 0 to 18 inches
Thickness of the mollic epipedon: 10 to 23 inches
Particle-size control section (weighted average):
Clay content: 3 to 10 percent
Sand content: 70 to 97 percent
Gravel content: 0 to 15 percent
A horizon:
Hue: 10YR or 2.5Y
Value: 3 to 5 (2 or 3 moist)
Chroma: 1 or 2
Some pedons have redoximorphic concentrations; common or many, distinct and prominent with hue of 5YR, 7.5YR, or 10YR, value of 3 to 5, and chroma of 3 to 6
Texture: loam, fine sandy loam or sandy loam but includes clay loam, mucky loam, very fine sandy loam,.
Clay content: 8 to 30 percent
Gravel content: 0 to 5 percent by volume
Reaction: slightly acid to moderately alkaline
Note: Some pedons have an organic surface layer 1 to 3 inches thick. Some pedons have A horizons that lack calcium carbonates.
AC horizon has textures and colors intermediate between the A and C horizons and sometimes lacks redoximorphic concentrations.
Cg horizon:
Hue: 10YR or 2.5Y
Value: 5 to 7 (4 to 6 moist)
Chroma: 1 or 2
Redoximorphic concentrations: common or many, distinct and prominent with hue of 5YR, 7.5YR, or 10YR, value of 4 or 5, and chroma of 4 to 8
Texture: fine sand, sand, loamy fine sand and loamy sand with thin strata of finer and coarser textured material
Clay content: 1 to 10 percent
Gravel content: 0 to 15 percent by volume
Reaction: neutral to moderately alkaline
2Ab horizon:
Hue: 10YR or 2.5Y
Value: 4 or 5, (2 or 3 moist)
Chroma: 1 or 2
Some pedons have redoximorphic concentrations: common or many, distinct and prominent with hue of 5YR, 7.5YR, or 10YR, value of 3 to 5, and chroma of 4 to 6
Texture: Loam or sandy loam but includes clay loam, fine sandy loam and very fine sandy loam with thin strata of coarser textured material
Clay content: 3 to 35 percent
Gravel content: 0 to 10 percent by volume
Reaction: neutral to moderately alkaline
Thickness: 0 to 14 inches, some pedons have loamy strata that is not dark in color
3Cg horizon:
Hue: 10YR or 2.5 Y
Value: 5 to 8 (4 to 7 moist)
Chroma: 1 or 2
Some pedons have redoximorphic concentrations: common or many, distinct and prominent with hue of 5YR, 7.5YR, or 10YR, value of 4 or 5, and chroma of 4 to 8
Texture: fine sand, sand, coarse sand, and gravelly coarse sand with thin strata of finer textured material
Clay content: 0 to 5 percent
Gravel content: 0 to 20 percent by volume
Reaction: neutral to moderately alkaline
COMPETING SERIES:These are the
Erber,
Gravelton and
Prochaska soils.
Erber: occurs at elevations greater than 3000 feet and in areas with a mean annual precipitation of less than 6 inches
Gravelton: occurs in area with a mean annual precipitation of more than 26 inches
Prochaska: has a Bw horizon and occurs in areas with a mean annual
precipitation of more than 26 inches
GEOGRAPHIC SETTING:
Parent material: sandy and gravelly alluvium
Landform: flood plain in stream valley
Slopes: 0 to 2 percent
Elevation: 1500 to 2100 feet
Mean annual temperature: 46 to 52 degrees F
Mean annual precipitation: 17 to 26 inches
Frost-free period: 125 to 165 days (50 percent probability at 32 degrees F or higher)
Growing season period: April 15 to October 15
GEOGRAPHICALLY ASSOCIATED SOILS:These are the
Barney,
Boel,
Inavale,
Calamus,
Lawet,
Orwet, and
Ovina.
Barney: are slightly lower on the flood plain and does not have a mollic epipedon
Boel: are slightly higher on the flood plain, and have a wet soil moisture status at depths of less than 1.5 feet (somewhat poorly drained)
Inavale: are higher on the flood plain, do not have a mollic epipedonand do not have a wet soil moisture status above 6 feet
Calamus: are higher on the flood plain, do not have a mollic epipedon, and have a wet soil moisture status starting at 3.0 feet (moderately well drained)
Lawet: are at the same elevations on the flood plain; are fine-loamy, and have a calcic horizon
Orwet: are at the same elevations on the flood plain and have a calcic horizon
Ovina: are slightly higher on the flood plain, are coarse loamy, and have a wet soil moisture status at 1.5 feet (somewhat poorly drained)
DRAINAGE AND PERMEABILITY:
Drainage: poorly drained and very poorly drained
Runoff: negligible
Permeability: rapid or very rapid
Wet soil moisture status: in the poorly drained phase it starts at 1/2 foot
Wet soil moisture status: in the very poorly drained phase it starts at the surface
Ponding: occasional, long duration, up to a depth of 0.5 feet on the very poorly drained phase
Flooding frequency: rare on the poorly drained phase and occasional on the very poorly drained phase
Flooding duration: brief on the poorly drained and very poorly drained phases
Flooding months: February through July on the poorly drained and very poorly drained phases.
USE AND VEGETATION: Most areas are in native grass and used as rangeland or hayland. They are too wet for cultivated crops. The native vegetation consists of big bluestem, switchgrass, indiangrass, prairie cordgrass and numerous sedges. In some areas the vegetation includes trees and shrubs.
DISTRIBUTION AND EXTENT: Central and north central Nebraska and south central South Dakota. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Keya Paha County, Nebraska, 2004
REMARKS: The Blackloup series includes soils previously mapped on flood plains as the Loup series. The Loup series has been mapped extensively on the non flooded interdunes in the sandhills and lacks an irregular decrease in organic carbon above 50 inches.
Diagnostic features recognized in this pedon:
mollic epipedon: the zone from 0 to 13 inches (A1, A2 and AC horizons)
fluvaquentic subgroup criteria: an irregular decrease in organic carbon in the 11 to 49 inch zone (AC, Cg 2Ab, 3Cg horizons)
aquic conditions: the zone from 11 to 80 inches (AC, Cg, 2Ab, 3Cg horizons)
07/2003 WAW A new type location was choosen and described.
1/2004 WAW: Updated the associated soils section as recommended by Roger Hammer, soil scientist O'Neill NE.