LOCATION JOHNSTOWN NE
Established Series
Rev. RRH, LGR
06/2022
JOHNSTOWN SERIES
The Johnstown series consists of very deep, well drained soils formed in loess and loamy sediments deposited on gravelly sand on uplands. Permeability is moderate in the solum and rapid or very rapid in the underlying material. Slopes range from 0 to 6 percent. Mean annual temperature is about 48 degrees F, and mean annual precipitation is about 20 inches.
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Pachic Argiustolls
TYPICAL PEDON: Johnstown loam - on a level slope of less than 1 percent, in an irrigated field of cultivated crops (colors are for dry soil unless otherwise stated).
Ap--0 to 8 inches; dark gray (10YR 4/1) loam, very dark gray (10YR 3/1) moist; weak medium platy structure parting to weak fine granular; slightly hard, very friable; few fine and very fine roots; moderately acid; abrupt smooth boundary.
A--8 to 21 inches; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; weak coarse prismatic structure parting to weak medium subangular blocky; slightly hard, very friable; few fine and very fine roots; slightly acid; clear smooth boundary. (Combined thickness of the A horizons is 7 to 23 inches.)
Bt--21 to 27 inches, grayish brown (10YR 5/2) clay loam, dark brown (10YR 3/3) moist; moderate coarse prismatic structure parting to moderate fine and medium subangular blocky; hard, firm; few fine and very fine roots; patchy very dark grayish brown (10YR 3/2) clay films on faces of peds; neutral; clear smooth boundary. (5 to 22 inches thick)
Btb1--27 to 36 inches; very dark grayish brown (10YR 3/2) silty clay loam, very dark brown (10YR 2/2) moist; moderate coarse prismatic structure parting to moderate fine and medium subangular blocky; hard, firm; patchy clay films on faces of peds; few fine and very fine roots; neutral; clear smooth boundary. (0 to 15 inches thick)
Btb2--36 to 44 inches; light yellowish brown (2.5Y 6/4) silty clay loam, olive brown (2.5Y 4/4) moist; moderate coarse prismatic structure parting to moderate medium subangular blocky; hard, firm; patchy clay films on faces of peds; few very fine roots; grayish brown (10YR 5/2) worm castings; neutral; clear smooth boundary. (4 to 14 inches thick)
BCb--44 to 50 inches; light yellowish brown (2.5Y 6/4) silty clay loam, olive brown (2.5Y 4/4) moist; weak coarse prismatic structure parting to weak medium subangular blocky; hard, friable; few very fine roots; few fine soft accumulations of carbonates; slight effervescence; slightly alkaline; abrupt wavy boundary. (0 to 16 inches thick)
2C--50 to 60 inches; light yellowish brown (10YR 6/4) gravelly coarse sand, yellowish brown (10YR 5/4) moist; single grain, loose, neutral.
TYPE LOCATION: Brown County, Nebraska; about 4 miles east and 2 miles North of Ainsworth; 500 feet east and 100 feet south of the northwest corner of sec. 14, T. 30 N., R. 21 W.
RANGE IN CHARACTERISTICS: Thickness of the mollic epipedon ranges from 20 to 44 inches. Thickness of the solum ranges from 30 to 55 inches. The depth to the 2C horizon typically ranges from 40 to 60 inches.
Depth to carbonates ranges from 30 to more than 60 inches. Depth to buried soils ranges from 14 to 36 inches.
The A horizon has hue of 10YR, value of 4 or 5 and 2 or 3 moist, and chroma of 1 through 3. It is typically loam but includes fine sandy loam, clay loam, or silt loam. It is moderately acid through neutral.
The Bt horizon has hue of 10YR, value of 4 or 5 and 3 moist, and chroma of 2 or 3. It is typically clay loam but includes silty clay loam. It averages between 27 and 35 percent clay. It is slightly acid or neutral.
The Btb1 horizon has hue of 10YR, value of 3 or 4 and 2 or 3 moist, and chroma of 1 or 2. It is clay loam or silty clay loam. It is slightly acid or neutral.
The Btb2 horizon has hue of 10YR or 2.5Y, value of 4 through 6 and 3 through 5 moist, and chroma of 2 through 4. It is silty clay loam or clay loam. It averages between 27 and 35 percent clay. It is neutral or slightly alkaline.
Some pedons have a BCkb horizon.
The BCb horizon and the C horizon, when present, have hues of 10YR or 2.5Y, value of 5 through 7 and 4 through 6 moist, and chroma of 2 through 4. They are loam, very fine sandy loam, silt loam or silty clay loam. They are neutral through moderately alkaline.
The 2C horizon has hue of 10YR or 2.5Y, value of 5 through 7 and 4 through 6 moist, and chroma of 2 through 4. It is typically gravelly coarse sand, but includes coarse sand, sand, fine sand, loamy fine sand or loamy sand. It contains 0 to 35 percent gravel by volume. It is neutral or slightly alkaline.
COMPETING SERIES: These are the
Goshen,
Hall,
Kuma,
Mobridge, and
Simpatico soils. Goshen, Hall, Kuma and Mobridge soils typically do not have coarse sand and gravel between a depth of 40 and 60 inches. Goshen, Hall and Mobridge soils do not have buried horizons above 40 inches. Simpatico soils are in an area with a drier climate and have redder hues in the argillic horizon.
GEOGRAPHIC SETTING: Johnstown soils are on nearly level to gently sloping uplands and tablelands. Surfaces are plane to convex. They formed in loess or loamy sediments deposited on gravelly sand. The mean annual temperature ranges from 46 to 50 degrees F, and the mean annual precipitation ranges from 16 to 22 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Anselmo,
Brocksburg,
Jansen, and
Oneill soils. Anselmo, and Oneill soils are generally on steeper slopes lower on the landscape. Anselmo soils are coarse-loamy. Oneill soils are moderately deep over coarse sand and gravel. They are coarse-loamy over sandy or sandy-skeletal. Brocksburg and Jansen soils occur on similar landscapes and are moderately deep over coarse sand and gravel. They are in the fine-loamy over sandy or sandy-skeletal family.
DRAINAGE AND PERMEABILITY: Well drained. Surface runoff is slow on the nearly level areas and medium on the more sloping areas. Permeability is moderate in the solum and rapid or very rapid in the underlying material.
USE AND VEGETATION: Nearly all areas are in cultivated cropland. Most of it is irrigated. Corn is the principal crop.
DISTRIBUTION AND EXTENT: North-central Nebraska and possibly south- central South Dakota. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Salina, Kansas
SERIES ESTABLISHED: Brown County, Nebraska, July 1987.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of approximately 36 inches (Ap, A, Bt, Btb1 horizons); argillic horizon - the zone from approximately 21 to 44 inches (Bt, Btb1, and Btb2 horizons).
ADDITIONAL DATA: Refer to Pedon No. 84NE-017-032 and S63NE-009-010 (LAB NOS. 68L049-68L050)
National Cooperative Soil Survey
U.S.A.