LOCATION NISHNA                  IA+MN NE

Established Series
Rev. RJK-LEB-DJP
08/2017

NISHNA SERIES

The Nishna series consists of very deep, poorly drained and very poorly drained soils formed in alluvium on flood plains. Slope ranges from 0 to 2 percent. Mean annual air temperature is about 11 degrees C. Mean annual precipitation is about 790 millimeters.

TAXONOMIC CLASS: Fine, smectitic, calcareous, mesic Cumulic Vertic Endoaquolls

TYPICAL PEDON: Nishna silty clay, on a slope of less than 1 percent in a cultivated field on a flood plain, at an elevation of about 293 meters above mean sea level. (All colors are for moist soil unless otherwise stated.)

Ap--0 to 18 centimeters; black (10YR 2/1) silty clay, very dark gray (10YR 3/1) dry; moderate medium subangular blocky structure parting to weak fine granular; friable; very few silt coats of grayish brown (10YR 5/2) dry; many roots; many pores; neutral; clear smooth boundary.

A1--18 to 41 centimeters; black (N 2.5/) silty clay, very dark gray (N 3/) dry; moderate fine subangular blocky structure; firm; sheen on faces of peds; many roots; many fine pores; slightly effervescent; slightly alkaline; clear smooth boundary.

A2--41 to 66 centimeters; black (10YR 2/1) silty clay, very dark gray (10YR 3/1) dry; moderate medium and fine subangular blocky structure; firm; few roots; few fine pores; gray calcium carbonate flecks and small calcium carbonate concretions; slightly effervescent; moderately alkaline; clear smooth boundary. (Combined thickness of the Ap and A horizon is 46 to 150 centimeters.)

Bkg--66 to 91 centimeters; very dark gray (N 3/) silty clay, dark gray (N 4/) dry; moderate fine subangular blocky structure; firm; few roots; few fine pores; many fine calcium carbonate masses and nodules; slightly effervescent; moderately alkaline; clear smooth boundary. (15 to 56 centimeters thick)

Cg--91 to 152 centimeters; dark gray (5Y 4/1) silty clay; very weak fine subangular blocky structure grading to massive; firm; few fine roots; few fine pores; many calcium carbonate masses and nodules; strongly effervescent; moderately alkaline.

TYPE LOCATION: Land Resource Unit (LRU) 107B - Iowa and Missouri Deep Loess Hills; Fremont County, Iowa; about 1 1/2 miles west and 1 mile north of Randolph; about 1,320 feet east and 1,320 feet north of the southwest corner of section 5, T. 70 N., R. 41 W.; USGS Tabor NE topographic quadrangle; lat. 40 degrees 53 minutes 30 seconds N. and long. 95 degrees 35 minutes 23 seconds W., NAD 83.

RANGE IN CHARACTERISTICS:
Mollic epipedon thickness--60 to more than 152 centimeters.
Sand content throughout--0 to 15 percent
Content of clay in the particle-size control section (weighted average)--35 to 46 percent
Depth to carbonates: throughout the series control section except the Ap horizons are usually leached of carbonates
Depth to redoximorphic concentrations (if present)--greater than 90 centimeters
Some pedons have snail shell fragments.
Depth to silt or sand stratification (if present)--greater than 120 centimeters
Electrical conductivity--0 to 2 mmhos/cm
Gypsum content--0 percent

Ap or A horizon:
Hue--10YR or neutral
Value-2, 2.5, or 3
Chroma--0 or 1
Texture--silty clay loam or silty clay
Clay content--35 to 45 percent
Moist bulk density--1.25 to 1.35 g/cc
Calcium carbonate equivalent--0 to 30 percent
Reaction--Ap horizon is neutral to moderately alkaline; A horizon is slightly alkaline or moderately alkaline

In overwash phases, a texture of silt loam with clay content of 20 to 27 percent is within the range of characteristics.

Some pedons have a buried soil at a depth of 45 to 90 centimeters.

Bg horizon (if present):
Thickness--15 to 45 centimeters
Hue--10YR to 5Y, or is neutral
Value--3 or 4
Chroma--0 or 1
Texture--silty clay
Clay content--40 to 50 percent
Moist bulk density--1.30 to 1.40 g/cc
Calcium carbonate equivalent--5 to 30 percent
Reaction--slightly alkaline or moderately alkaline

Bkg horizon:
Hue--10YR to 5Y, or is neutral
Value-3 or 4
Chroma--0 or 1
Clay content--38 to 50 percent
Moist bulk density--1.30 to 1.40 g/cc
Calcium carbonate equivalent--5 to 30 percent
Reaction--slightly alkaline or moderately alkaline

Cg horizon:
Hue--10YR to 5Y, or is neutral
Value--3 or 4
Chroma--0 or 1
Texture--silty clay or clay
Clay content--50 to 60 percent
Moist bulk density--1.35 to 1.45 g/cc
Calcium carbonate equivalent--5 to 30 percent
Reaction--slightly alkaline or moderately alkaline

COMPETING SERIES: These are the Baltic, Delvada, James, and Knoke series.
Baltic--have gypsum within the series control section
Delvada--have a horizon with electrical conductivity of more than 2 mmhos/cm within a depth of 100 centimeters
James--have an electrical conductivity of more than 2 mmhos/cm in the upper part of the series control section
Knoke--average more than 15 percent sand in the particle-size control section

GEOGRAPHIC SETTING:
Parent material-alluvium
Landform-flood plain; back swamp positions often some distance from the main stream channel
Slope--0 to 2 percent
Elevation--185 to 335 meters above mean sea level
Mean annual air temperature--4 to 13 degrees C
Mean annual precipitation--485 to 1040 millimeters
Frost-free period--140 to 220 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bremer, Calco, Colo, Marshall, Nevin, Nodaway, and Zook soils.
Bremer--are on higher landscape positions, have carbonates deeper than 152 centimeters, and are in the Argiaquolls Great Group
Calco--have 24 to 35 percent clay in the particle-size control section and are in the Cumulic Endoaquolls Subgroup
Colo--are on higher landscape positions, have carbonates deeper than 150 centimeters, and are in the Cumulic Endoaquolls Subgroup
Marshall--are formed in loess on adjacent side slopes of uplands and stream terraces
Nevin--are on higher landscape positions, have carbonates deeper than 150 centimeters, have 30 to 35 percent clay in the particle-size control section, and are in the Argiudolls Great Group
Nodaway--are on higher landscape positions and are in the fine-silty particle-size class
Zook--are on higher landscape positions and have carbonates at 150 to more than 200 centimeters

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage--water saturation occurs between 0 to 30 centimeters from March through June in years with normal precipitation (when precipitation is within one standard deviation of the 30-year mean of annual precipitation) (poorly drained). This saturation is considered apparent.
Ponding--up to 30 centimeters deep (very poorly drained)
Saturated Hydraulic Conductivity--0.01 to 0.10 micrometers per second.
Flooding--occasional or rare for brief periods

USE AND VEGETATION: Native vegetation includes prairie cordgrass, sedges, river bulrush and other species of the tall grass prairie that are tolerant of wetness. Corn and soybeans are the principal crops when adequate drainage is possible. Some small grain and hay is also grown. See Additional Data section for native vegetative cover in Iowa and Minnesota.

DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic Sections--Western Lake; Dissected Till Plains
Land Resource Region--Central Feed Grains and Livestock Region (M)
MLRAs and LRUs:
--Rolling Till Prairie (102A)
--Loess Uplands (102C)
--Central Iowa and Minnesota Till Prairies (103)
--Nebraska and Kansas Loess-Drift Hills (106)
--Iowa and Minnesota Loess Hills (107A)
--Iowa and Missouri Deep Loess Hills (107B)
Extent--moderate; 11,115 hectares (27,454 acres) have been correlated

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana.

SERIES ESTABLISHED:
Fremont County, Iowa, 1974.

REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section--the zone from a depth of 25 to 100 centimeters (A1, A2, Bkg, Cg horizons).
Series control section--the zone from the surface to a depth of 150 centimeters (Ap, A1, A2, Bkg, Cg horizons).
Mollic epipedon--the zone from the surface to a depth of 91 centimeters (Ap, A1, A2 and Bkg horizons).
Aquic moisture regime.

Taxonomy version--Keys to Soil Taxonomy, Twelfth Edition, 2014.

ADDITIONAL DATA: In Iowa and Minnesota, the native vegetative cover is an herbaceous wetland community commonly inhabited with Rice Cutgrasses, Softstem Bulrushes, Needle Spikerushes, Broadfruit Burreeds, Pickerel Weeds, Broadleaf Cattails, Water Smartweeds, American Water Lilies, Yellow Pond Lilies, American Lotuses, Small Pondweeds, Sago Pondweeds, and Arrowheads. Source: Iowa State Office, Natural Resources Conservation Service, Des Moines, IA.

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National Cooperative Soil Survey
U.S.A.