LOCATION NEVIN                   IA+MO

Established Series
Rev. RID-SRS-DJP
07/2018

NEVIN SERIES

The Nevin series consists of very deep, somewhat poorly drained soils that formed in silty alluvium. Nevin soils are on treads and risers on low stream terraces. Slope ranges from 0 to 5 percent. Mean annual precipitation is about 835 millimeters. Mean annual air temperature is about 10 degrees C.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Aquic Pachic Argiudolls

TYPICAL PEDON: Nevin silty clay loam, on a nearly level slope, in a cultivated field, at an elevation of 333.1 meters above sea level. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 20 centimeters; black (10YR 2/1) silty clay loam, dark gray (10YR 4/1) dry; weak fine and very fine granular structure; friable; slightly acid; clear smooth boundary.

A1--20 to 33 centimeters; black (10YR 2/1) silty clay loam, dark gray (10YR 4/1) dry; moderate fine granular and weak very fine subangular blocky structure; friable; slightly acid; gradual smooth boundary.

A2--33 to 48 centimeters; black (10YR 2/1) silty clay loam, dark gray (10YR 4/1) dry; weak very fine subangular blocky and weak fine granular structure; friable; slightly acid; gradual smooth boundary.

A3--48 to 61 centimeters; very dark gray (10YR 3/1) silty clay loam, very dark grayish brown (10YR 3/2) kneaded, dark grayish brown (10YR 4/2) dry; weak very fine subangular blocky structure; friable; slightly acid; gradual smooth boundary. (Combined thickness of the A horizon is 50 to 75 centimeters.)

BA--61 to 76 centimeters; dark grayish brown (10YR 4/2) silty clay loam, faces of peds very dark gray (10YR 3/1), very dark grayish brown (10YR 3/2) kneaded, grayish brown (10YR 5/2) dry; weak very fine subangular blocky structure; friable; slightly acid; clear smooth boundary. (0 to 15 centimeters thick)

Btg1--76 to 91 centimeters; dark grayish brown (10YR 4/2) silty clay loam; weak medium prismatic structure parting to weak fine subangular blocky; friable; few distinct clay films; dark grayish brown (10YR 4/2) and very dark grayish brown (10YR 3/2) coats on faces of peds; slightly acid; gradual smooth boundary.

Btg2--91 to 104 centimeters; dark grayish brown (10YR 4/2) silty clay loam; weak medium prismatic structure parting to weak fine subangular blocky; firm; few distinct clay films; common very dark grayish brown (10YR 3/2) coats on faces of peds; few fine black concretions (oxides); common fine and medium faint grayish brown (10YR 5/2) redoximorphic depletions; slightly acid; gradual smooth boundary.

Btg3--104 to 117 centimeters; dark grayish brown (10YR 4/2) and olive brown (2.5Y 4/4) silty clay loam; weak medium prismatic structure parting to weak fine subangular blocky; firm; few distinct clay films on faces of peds and along surfaces of pores; common fine black concretions (oxides); common fine faint grayish brown (10YR 5/2) redoximorphic depletions; slightly acid; gradual smooth boundary. (Combined thickness of the Btg horizon is 35 to 60 centimeters.)

BC1--117 to 132 centimeters; brown (10YR 4/3) silty clay loam; faces of peds dark grayish brown (10YR 4/2); weak medium prismatic structure parting to weak medium subangular blocky; friable; common fine black concretions (oxides); few fine faint yellowish brown (10YR 5/4) redoximorphic concentrations; slightly acid; diffuse smooth boundary.

BC2--132 to 158 centimeters; brown (10YR 4/3) silty clay loam; weak very coarse prismatic structure; firm; common fine black concretions (oxides); few fine faint grayish brown (10YR 5/2) redoximorphic depletions; few fine faint yellowish brown (10YR 5/4) redoximorphic concentrations; neutral.

TYPE LOCATION: Land Resource Unit (LRU) 107B-Iowa and Missouri Deep Loess Hills; Cass County, Iowa; about 1 1/2 miles north and 1 mile west of Griswold; about 920 feet east and 1,620 feet south of the northwest corner of sec. 31, T. 75 N., R. 37 W.; USGS Atlantic SW topographic quadrangle; lat. 41 degrees 15 minutes 24.4 seconds N. and long. 95 degrees 9 minutes 8.3 seconds W., NAD 83.

RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon--50 to 90 centimeters
Depth to carbonates--more than 150 centimeters
Clay content of the particle-size control section (weighted average)--30 to 35 percent
Sand content of the particle-size control section (weighted average)--5 to 15 percent

A or Ap horizon:
Hue--10YR
Value--2 or 3
Chroma--1 or 2
Texture--silt loam or silty clay loam
Clay content--26 to 29 percent
Sand content--5 to 15 percent
Reaction-- moderately acid to neutral

Some pedons have an AB horizon.

BA or Btg horizon:
Hue--10YR or 2.5Y
Value--4 or 5
Chroma--2 to 4
Texture--silty clay loam
Clay content--30 to 35 percent
Sand content--5 to 15 percent
Reaction--moderately acid to neutral

BC or C (when present) horizon:
Hue--10YR or 2.5Y
Value--4 or 5
Chroma--1 to 4
Texture--silty clay loam or silt loam
Clay content--25 to 36 percent
Sand content--5 to 15 percent
Reaction--slightly acid or neutral

2C horizon (below 150 centimeters if present):
Hue--10YR or 2.5Y
Value--4 to 6
Chroma--1 to 4
Texture--loamy sand, sandy loam, or sand, or their gravelly analogs
Clay content--3 to 10 percent
Sand content--60 to 95 percent
Reaction--slightly acid to slightly alkaline

COMPETING SERIES: These are no other series in this family.

GEOGRAPHIC SETTING:
Parent material--silty alluvium
Landform--treads and risers on low stream terraces
Slope--0 to 5 percent
Elevation--168 to 396 meters above sea level
Mean annual air temperature--8 to 12 degrees C
Mean annual precipitation--700 to 970 millimeters
Frost-free period--160 to 180 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bremer, Nodaway, Wiota, and Zook soils.
Bremer--are on lower landscape positions on low stream terraces and average more than 35 percent clay in the particle-size control section
Nodaway--are on lower landscape positions on floodplains adjacent to stream channels and do not have a frequently saturated zone within a depth of 1 meter during the wettest periods of normal years
Wiota--are on slightly higher landscape positions on stream terraces and have a frequently saturated zone at a depth of 1.2 meters during the wettest periods of normal years
Zook--are on lower landscape positions on floodplains, are frequently saturated at the soil surface during the wettest periods of normal years and have a mollic epipedon more than 90 centimeters thick

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--somewhat poorly drained--a frequently saturated zone occurs at a depth of 0.3 meter during April to June in normal years and is considered apparent
Saturated hydraulic conductivity--1.00 to 10.00 micrometers per second
Potential surface runoff--low
Flooding--rare or occasional flooding for brief or very brief duration

USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn, soybeans, small grains, and legume hay. The native vegetation is big bluestem, little bluestem, switchgrass, and other grasses of the tall grass prairie.

DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic section--Dissected till plains
MLRAs and LRUs--Eastern Iowa and Minnesota Till Prairies (104); Northern Mississippi Valley Loess Hills (105); Iowa and Missouri Deep Loess Hills (107B); Illinois and Iowa Deep Loess and Drift (108); Iowa and Missouri Heavy Till Plain (109); Cherokee Prairies (112); Central Mississippi Valley Wooded Slopes (115); and Ozark Highland (116)
LRR--M and N; southern Iowa and Missouri
Extent--moderate

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

SERIES ESTABLISHED: Adams County, Iowa, 1960.

REMARKS:
Diagnostic horizons and features recognized in this pedon include:
Particle-size control section--the zone from a depth of 76 to 117 centimeters.
Series control section--the zone from the surface to a depth of 150 centimeters.
Mollic epipedon--the zone from the surface to a depth of 76 centimeters (Ap, A1, A2, A3, and BA horizons).
Argillic horizon--the zone from a depth of 76 to 117 centimeters (Bt1, Bt2, and Bt3 horizons).
Udic moisture regime.

Aquic subgroup--based on low chroma matrix of zone from a depth of 61 to 76 centimeters (BA horizon)

Pachic subgroup--mollic colors 76 centimeters thick

Cation-exchange activity class is inferred from lab data from similar soils in the surrounding area

Taxonomic version--Twelfth Edition, 2014.

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National Cooperative Soil Survey
U.S.A.