LOCATION PERCIVAL IA+MO NE SD

Established Series
Rev. JRN-RAL-DJP
07/2018

PERCIVAL SERIES

The Percival series consists of very deep, somewhat poorly drained soils on flood plains. These soils formed in 38 to 76 centimeters (15 to 30 inches) of clayey alluvium and the underlying sandy alluvium. Slope ranges from 0 to 6 percent. Mean annual air temperature is about 11 degrees C (51 degrees F). Mean annual precipitation is about 710 millimeters (28 inches).

TAXONOMIC CLASS: Clayey over sandy or sandy-skeletal, smectitic over mixed, calcareous, mesic Aquic Udifluvents

TYPICAL PEDON: Percival silty clay, on about a 1 percent slope, on a flood plain, in a cultivated field, at an elevation of 306 meters (1,005 feet) above sea level. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 20 centimeters (0 to 8 inches); very dark gray (10YR 3/1) silty clay, gray (10YR 5/1) dry; weak fine subangular blocky structure; firm; few fine pores; few strong brown (7.5YR 5/6) root stains; slightly effervescent; slightly alkaline; clear smooth boundary. [15 to 23 centimeters (6 to 9 inches) thick]

Cg1--20 to 61 centimeters (8 to 24 inches); grayish brown (2.5Y 5/2) and dark gray (5Y 4/1) silty clay, dark grayish brown (2.5Y 4/2) crushed; firm; few very fine pores; massive with weak, thin alluvial stratification; few fine prominent dark reddish brown (5YR 3/4) and strong brown (7.5YR 5/6) redoximorphic concentrations; strongly effervescent; slightly alkaline; abrupt smooth boundary. [23 to 53 centimeters (9 to 21 inches) thick]

2Cg2--61 to 152 centimeters (24 to 60 inches); stratified grayish brown (2.5Y 5/2) loamy fine sand and fine sand; single grain; loose; common fine dark masses (Fe-Mn oxides); few fine prominent strong brown (7.5YR 5/6) and brown (7.5YR 4/4) redoximorphic concentrations; few fine faint gray (10YR 5/1) redoximorphic depletions; strongly effervescent; slightly alkaline.

TYPE LOCATION: Land Resource Unit (LRU) 107B-Iowa and Missouri Deep Loess Hills; Harrison County, Iowa; about 3 miles south of Modale; about 490 feet south and 2,550 feet west of the northeast corner of sec. 9, T. 78 N., R. 45 W.; USGS Modale topographic quadrangle; lat. 41 degrees 34 minutes 45 seconds N. and long. 96 degrees 1 minute 23 seconds W., NAD 83.

RANGE IN CHARACTERISTICS:
Depth to carbonates--0 to 25 centimeters (0 to 10 inches)
Depth to sandy alluvium--38 to 76 centimeters (15 to 30 inches)
Thickness of the ochric epipedon--15 to 23 centimeters (6 to 9 inches)
Clay content in the upper third to upper half of the particle-size control section (weighted average)--40 to 60 percent
Clay content in the lower half to lower two thirds of the particle-size control section (weighted average)--2 to 10 percent
Sand content in the upper third to upper half of the particle-size control section (weighted average)--0 to 5 percent fine sand and sand coarser than fine sand
Sand content in the lower half to lower two thirds of the particle-size control section (weighted average)--70 to 95 percent fine sand and sand coarser than fine sand

Ap horizon:
Hue--10YR or 2.5Y
Value--3 or 4
Chroma--1 or 2
Texture--silty clay, silty clay loam, or clay
Clay content--35 to 60 percent
Sand content--0 to 5 percent
Calcium carbonate equivalent--0 to 15 percent
Reaction--slightly alkaline or moderately alkaline

Cg horizon:
Hue--2.5Y or 5Y
Value--4 or 5
Chroma--1 or 2
Texture--clay or silty clay
Clay content--40 to 60 percent
Sand content--0 to 5 percent
Calcium carbonate equivalent--0 to 25 percent
Reaction--slightly alkaline or moderately alkaline

Some pedons have transitional horizons, less than 13 centimeters (5 inches) thick, with a texture of silty clay loam.

2Cg horizon:
Hue--2.5Y
Value--4 to 6
Chroma--2
Texture--fine sand or loamy fine sand
Clay content--2 to 10 percent
Sand content--70 to 95 percent, dominantly fine sand and medium sand
Calcium carbonate equivalent--0 to 25 percent
Reaction--slightly alkaline or moderately alkaline

Some pedons have lenses, less than 15 centimeters (6 inches) thick, in the middle or lower part of this horizon with textures of silt loam, loam, silty clay loam, or silty clay.

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

GEOGRAPHIC SETTING:
Parent material--38 to 76 centimeters (15 to 30 inches) of clayey alluvium and the underlying sandy alluvium
Landform--flood plains
Slope--0 to 6 percent
Elevation--213 to 384 meters (700 to 1,260 feet) above sea level
Mean annual air temperature--8 to 13 degrees C (47 to 56 degrees F)
Mean annual precipitation--510 to 910 millimeters (20 to 36 inches)
Frost-free period--135 to 180 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Albaton, Haynie, Modale, and Sarpy soils.
Albaton--are in the slightly lower landscape positions, have a saturated zone within a depth of 30 centimeters (1 foot) during March to June in most years, and have a clay content of 50 to 60 percent throughout the particle-size control section
Haynie--are in the slightly higher landscape positions, have a clay content of 15 to 18 percent throughout the particle-size control section, and have a saturated zone between depths of 120 to 180 centimeters (4 to 6 feet) during April to June in most years
Modale--are in the slightly higher landscape positions, have a clay content of 10 to 18 percent in the upper third to upper half of the particle-size control section, and have a saturated zone between depths of 30 to 90 centimeters (1 to 3 feet) during April to June in most years
Sarpy--are in the higher landscape positions, have a clay content of 2 to 5 percent throughout the particle-size control section, and do not have a saturated zone within a depth of 180 centimeters (6 feet) in most years

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--somewhat poorly drained--a saturated zone occurs within depths of 30 to 90 centimeters (1 to 3 feet) during March to June in most years and is considered apparent
Saturated hydraulic conductivity--0.01 to 0.10 micrometers per second in the clayey alluvium and 10.00 to 100.00 micrometers per second in the underlying sandy alluvium
Permeability--slow in the clayey alluvium and rapid in the underlying sandy alluvium
Surface runoff potential--medium
Flooding--rare to frequent flooding with very brief to long duration during the months of February to November from precipitation events and snowmelt and flooding from streambank overflow is limited where dams and levees protect areas

USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn and soybeans. A few areas are land-leveled and irrigated. The native vegetation is big bluestem, little bluestem, western wheatgrass, indiangrass, switchgrass, and other grasses of the tall grass prairie.

DISTRIBUTION AND EXTENT:
LRUs--Iowa and Missouri Deep Loess Hills (107B); Loess Uplands and Till Plains (102B); and Loess Uplands (102C)
LRR--M; along the Missouri River in Iowa, Missouri, Nebraska, and South Dakota
Extent--moderate

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

SERIES ESTABLISHED: Harrison County, Iowa, 1971.

REMARKS:
Diagnostic horizons and features recognized in this pedon:
Particle-size control section--the zone from a depth of 25 to 100 centimeters (10 to 40 inches - Cg1 and 2Cg2 horizons).
Series control section--the zone from the surface to a depth of 150 centimeters (60 inches - Ap, Cg1, and 2Cg2 horizons).
Ochric epipedon--the zone from the surface to a depth of 20 centimeters (8 inches - Ap horizon).
Udic moisture regime.

Cation-exchange activity class is supported by lab sample number S96IA-193-019, National Soil Survey Laboratory.

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

The colors of materials appear to be inherited from the alluvium. The underlying sand may be water-bearing during some period of the year, however, these soils are not artificially drained.

ADDITIONAL DATA:
Laboratory data--National Soil Survey Laboratory, Lincoln, Nebraska pedon S96IA-193-019 (http://ssldata.sc.egov.usda.gov/).

National Cooperative Soil Survey
U.S.A.