LOCATION NAHON SD+ND
Established Series
Rev. LDS-BOK
07/2014
NAHON SERIES
The Nahon series consists of very deep, moderately well drained and somewhat poorly drained soils formed in clayey glaciolacustrine sediments on lake plains. Permeability is very slow in the subsoil. Slopes range from 0 to 2 percent. Mean annual precipitation is about 19 inches, and mean annual air temperature is about 43 degrees F.
TAXONOMIC CLASS: Fine, smectitic, frigid Calcic Natrudolls
TYPICAL PEDON: Nahon silty clay loam - on a plain slope of less than 1 percent in a cultivated field. When described the soil was dry to 50 inches and moist below. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 6 inches; dark gray (10YR 4/1) silty clay loam, black (10YR 2/1) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; slightly acid; abrupt smooth boundary. (5 to 11 inches thick)
E--6 to 9 inches; gray (10YR 6/1) and (10YR 5/1) silt loam, dark grayish brown (10YR 4/2) and very dark gray (10YR 3/1) moist; weak medium platy structure; slightly hard, friable, slightly sticky and slightly plastic; neutral; abrupt smooth boundary. (1 to 6 inches thick)
Btn1--9 to 14 inches; gray (10YR 5/1) silty clay, very dark gray (10YR 3/1) moist; weak medium and fine columnar structure parting to moderate fine blocky; very hard, firm, sticky and plastic; thin continuous shiny films on vertical faces of peds; thin continuous gray (10YR 6/1) coatings on column tops; slightly alkaline; clear wavy boundary.
Btn2--14 to 20 inches; grayish brown (10YR 5/2) silty clay loam, very dark gray (10YR 3/1) moist; moderate medium and fine prismatic structure parting to moderate medium blocky; hard, firm, sticky and plastic; thin continuous shiny films on vertical faces of peds; few fine nests of salts in the lower part; moderately alkaline; clear wavy boundary. (Combined thickness of Bt horizons is 8 to 17 inches.)
Bz--20 to 25 inches; light brownish gray (2.5Y 6/2) and pale yellow (2.5Y 7/4) silty clay loam, dark grayish brown (2.5Y 4/2) and light olive brown (2.5Y 5/4) moist; weak medium prismatic structure parting to weak medium subangular blocky; hard, firm, sticky and plastic; common fine nests of gypsum and other salts; few fine accumulations of carbonate; slight effervescence; slightly alkaline. (0 to 20 inches thick)
Bkz--25 to 37 inches; pale yellow (2.5Y 7/4) silty clay loam, light olive brown (2.5Y 5/4) moist; weak coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine nests of gypsum and other salts; violent effervescence (21 percent calcium carbonate equivalent); moderately alkaline; clear wavy boundary. (0 to 18 inches thick)
C1--37 to 56 inches; pale yellow (2.5Y 8/2) and grayish brown (2.5Y 5/2) silty clay loam, varved with thin layers of very fine sandy loam and silty clay, pale yellow (2.5Y 7/4) and dark grayish brown (2.5Y 4/2) moist; massive, varves 1 to 3 mm thick; slightly hard, friable, slightly sticky and slightly plastic; violent effervescence (14 percent calcium carbonate equivalent); moderately alkaline; gradual wavy boundary.
C2--56 to 60 inches; pale yellow (2.5Y 8/2) and grayish brown (2.5Y 5/2) clay varved with thin layers of very fine sandy loam and silty clay, pale yellow (2.5Y 7/4) and dark grayish brown (2.5Y 4/2) moist; massive, varves 5 to 10 mm thick; hard, firm; strong effervescence; moderately alkaline.
TYPE LOCATION: Brown County, South Dakota; about 6 miles south of Aberdeen; 1160 feet south and 260 feet west of the northeast corner, sec. 9, T. 122 N., R. 63 W.
RANGE IN CHARACTERISTICS: Depth to free carbonate ranges from 14 to 32 inches. The natric horizon has a SAR that ranges from 5 to 15 and an ESP that ranges from 5 to 25. The ESP exceeds 15 within 2 meters of the upper boundary of the Bt horizon. Depth to accumulated salts ranges from 16 to 24 inches.
The A horizon has value of 3 or 4 and 2 or 3 moist. It is silt loam or silty clay loam and ranges from moderately acid to neutral.
The E horizon has value of 5 or 6 and 3 or 4 moist, and chroma of 1 or 2. It is silt loam or silty clay loam and is moderately acid to neutral. The E horizon is absent in some pedons that have an Ap horizon.
The Btn horizon has hue of 10YR or 2.5Y, value of 3 to 5 and 2 or 3 moist, and chroma of 1 to 3. It is silty clay or silty clay loam that averages between 35 and 55 percent clay. It is neutral to strongly alkaline. Some pedons do not have gypsum or/other salts in the lower part of the Btn horizon or have a Btnz horizon.
The Bz and Bkz horizons have hue of 10YR, 2.5Y, or 5Y; value of 4 to 8 and 3 to 6 moist; and chroma of 1 to 4. They are typically silty clay loam or silty clay but some pedons are silt loam. Reaction ranges from slightly alkaline to strongly alkaline. Gypsum and other salts range from few to common. Some pedons have a Bkyz, BC or By horizon.
The C horizon has hue of 2.5Y or 10YR, value of 5 to 8 and 4 to 7 moist, and chroma of 2 to 4. It is silty clay loam, clay, and silty clay. The lower part is varved very fine sand to clay. It is moderately or strongly alkaline. Varves range from 1 mm to 10 mm in thickness. Some pedons are underlain with sandy materials or loamy glacial till at depths of 40 to 60 inches.
COMPETING SERIES: These are the
Cavour and
Rich series. Cavour soils contain more than 15 percent fine sand or coarser throughout the series control section. Rich soils do not have an E horizon and are drier in the soil moisture control section for longer periods.
GEOGRAPHIC SETTING: The Nahon soils are on nearly level to level glacial lake plains. Slope gradients are 2 percent or less. The soils formed in calcareous lacustrine deposits of silt, very fine sand, and clay. Mean annual air temperature ranges from 36 to 45 degrees F, and mean annual precipitation from 16 to 24 inches. Most of the precipitation comes in the spring and summer. Growing season is about 120 to 130 days; average growing season precipitation is 14 to 18 inches; and growing degree days are about 2500 to 3000.
GEOGRAPHICALLY ASSOCIATED SOILS: These are
Aberdeen,
Exline,
Great Bend,
Harmony and
Overly soils. The Aberdeen, Exline, and Harmony soils are on the broad smooth flats in close association with the Nahon soil. Aberdeen soils are glossic. Exline soils have accumulations of salts within 16 inches and have a thinner sola. Harmony soils do not have a natric horizon. The
Beotia and Great Bend soils are on slightly higher positions. The Great Bend and Overly soils are on slightly higher positions. They do not have a natric horizon and are fine-silty.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained or moderately well drained. Runoff is medium to high depending on slope. Permeability is very slow.
USE AND VEGETATION: The majority of the Nahon soils are cropped to small grains, alfalfa, and pasture. Native vegetation mainly is western wheatgrass, green needlegrass, blue grama, buffalograss, needleandthread, sedges and forbs.
DISTRIBUTION AND EXTENT: Northeastern South Dakota and eastern North Dakota. The series is extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Pembina County, North Dakota, 1973.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of about 6 inches and from 9 to about 20 inches (A, Btn1, Btn2 horizons); natric horizon - the zone from a depth of about 9 to 20 inches (Btn1 and Btn2 horizons), and calcic horizon - the zone from 25 to 37 inches (Bkz horizon).
ADDITIONAL DATA: NSSL Sample Nos. 74K1060-9.
National Cooperative Soil Survey
U.S.A.