LOCATION DEVOIGNES ID

Established Series
Rev. JCC-AVY-EMM
10/2013

DEVOIGNES SERIES

The DeVoignes series consists of very deep, very poorly drained soils in depressions and swales on flood plains, drainageways and valley floors. They formed in mixed alluvium that is stratified with organic layers in the upper part. Slope ranges from 0 to 2 percent. The average annual air temperature is about 44 degrees F. and the average annual precipitation is about 22 inches.

TAXONOMIC CLASS: Fine-silty, mixed, active, nonacid, frigid Histic Humaquepts

TYPICAL PEDON: DeVoignes mucky silty loam, cultivated; on a 0 percent slope at 1,760 feet elevation. When described on October 12, 1970, the soil was moist throughout. (Colors are for dry soil unless otherwise stated.) Pedon was re-described on October 10, 1994.

Ap--0 to 9 inches; light gray (10YR 7/1) and gray (10YR 6/1) mucky silt loam, dark gray (10YR 4/1) moist; weak coarse subangular blocky structure parting to weak fine granular; soft, friable, slightly sticky and slightly plastic; many fine roots; many very fine pores; strongly effervescent (calcium carbonate); moderately alkaline (pH 8.0); abrupt wavy boundary. (6 to 11 inches thick)

Oa/C--9 to 19 inches; dark gray (10YR 4/1) muck, black (10YR 2/1) moist, with thin layers of gray (10YR 6/1) silty clay loam, dark gray (10YR 4/1) moist; massive; hard, firm, slightly sticky and slightly plastic; many fine roots; many fine pores; moderately acid (pH 5.9); abrupt smooth boundary. (6 to 13 inches thick)

Oa/Cg--19 to 24 inches; alternate thin layers of muck and silty clay loam; muck part is dark gray (10YR 4/1), black (10YR 2/1) and very dark grayish brown (10YR 3/2) moist; silty clay loam part is gray (10YR 6/1), dark gray (10YR 4/1) moist; weak medium platy and weak coarse prismatic structure; hard, friable, slightly sticky and slightly plastic; many very fine pores; many medium faint light yellowish brown (10YR 6/4) masses of iron accumulation; neutral (pH 7.0); abrupt wavy boundary. (3 to 9 inches thick)

2Cg1--24 to 28 inches; gray (5Y 6/1) silty clay loam, dark gray (2.5Y 4/1) moist; weak very coarse prismatic structure; very hard, firm, moderately sticky and moderately plastic; many fine to coarse pores and root channels with organic staining; many medium distinct dark brown (7.5YR 3/4) moist masses of iron accumulation; many snail shells; strongly effervescent (calcium carbonate); moderately alkaline (pH 8.0); abrupt wavy boundary. (4 to 11 inches thick)

2Cg2--28 to 41 inches; gray (5Y 6/1) silty clay loam, dark gray (5Y 4/1) moist; weak very coarse prismatic structure; very hard, firm, moderately sticky and moderately plastic; many fine and medium tubular pores; common prominent reddish brown (5YR 4/4) moist masses of iron accumulation; slightly alkaline (pH 7.5); clear smooth boundary. (11 to 18 inches thick)

2Cg3--41 to 65 inches; light gray (5Y 7/1) stratified silty clay loam and silty clay, gray (5Y 5/1) moist; massive; very hard, firm, moderately sticky and moderately plastic; many fine tubular pores; common faint and prominent fine and coarse light olive brown (2.5Y 5/4) and reddish brown (5YR 4/4) moist masses of iron accumulation; noneffervescent (calcium carbonate) in upper part and strongly effervescent (calcium carbonate) in lower part; slightly alkaline (pH 7.5).

TYPE LOCATION: Boundary County, Idaho; in the University of Idaho experimental plots west of Allens Spur; about 1,820 feet north and 100 feet west of the southeast corner of section 7, T. 62 N., R. 1 E.; Latitude - 48 degrees, 44 minutes, 13 seconds North; Longitude - 116 degrees, 22 minutes, 26 seconds West; USGS Bonners Ferry Quadrangle.

RANGE IN CHARACTERISTICS:

Average annual soil temperature - 45 to 47 degrees F.
Average summer soil temperature - 59 to 63 degrees F.
Depth to seasonal high water table - 0 to 24 inches January to December in undrained areas; 18 to 48 inches December to July in drained areas
Snail shells - in layers or scattered throughout the profile
Cracks - 1/2 to 2 inches wide to a depth of 36 inches when dry in summer
Clay content - 18 to 45 percent (averages less than 35 percent in the particle-size control section

Ap horizon
Hue - 10YR or 2.5Y
Value - 6 or 7 dry, 4 or 5 moist
Texture - mucky silt loam or silt loam
Clay content - 12 to 26 percent
Effervescence - none to strongly effervescent
Calcium carbonate equivalent - 0 to 15 percent
Reaction - very strongly acid to moderately alkaline*

Oa/C horizon
Hue - 10YR or 2.5Y
Texture - stratified muck, silt loam or silty clay loam
Clay content - 18 to 35 percent
Calcium carbonate equivalent - 0 to 5 percent
Calcium carbonate equivalent - 0 to 5 percent
Reaction - very strongly acid to neutral*

Oa/Cg horizon
Hue - 10YR or 2.5Y
Texture - stratified muck, silt loam or silty clay loam
Clay content - 18 to 35 percent
Calcium carbonate equivalent - 0 to 5 percent
Reaction - very strongly acid to slightly alkaline*

2Cg horizons
Hue - 2.5Y, 10YR or 5Y, 5G or 5B lower part in some pedons
Value - 6 or 7 dry, 4 or 5 moist
Texture - stratified silt loam, silty clay loam or silty clay
Clay content - 26 to 45 percent
Calcium carbonate equivalent - 0 to 20 percent
Reaction - very strongly acid to moderately alkaline*

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: DeVoignes soils are in depressions and swales of flood plains, drainageways and valley floors. Slopes range from 0 to 2 percent. They formed in mixed alluvium that is stratified with organic layers in the upper part. Elevations range from 1,750 to 2,800 feet. The climate is characterized by cold, wet winters and warm, dry summers. The average annual air temperature ranges from 43 to 46 degrees F. and the average annual precipitation is 20 to 30 inches. The average frost-free period is 90 to 140 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bellslake, Farnhamton, Pywell, Ritz, and Schnoorson soils. Bellslake soils are on floodplains and do not have a histic epipedon (organic materials are below 35 inches). Farnhamton soils are on natural levees on flood plains, are coarse-silty and are moderately well drained. Pywell soils are in depressions on floodplains and have organic material to a depth of 40 inches or more. Ritz soils are on low stream terraces and flood plains and are coarse-silty. Schnoorson soils are on depressions and swales on flood plains and do not have organic horizons.

DRAINAGE AND PERMEABILITY: Poorly drained; very slow runoff; saturated hydraulic conductivity is moderately high. Most of these soils have been artificially drained. These soils are subject to frequent flooding for very long periods from December to June unless protected by levees. Protected areas are subject to rare or occasional flooding.

USE AND VEGETATION: Used mostly for spring wheat, oats, barley, clover seed, hay and pasture where drained and protected. Some areas are used for wetlands, wildlife habitat and recreation. Natural vegetation is mainly Pacific willow, cattails, sedges, rushes, thinleaf alder, pyramid spirea, and Douglas hawthorne.

DISTRIBUTION AND EXTENT: Northern Idaho, and possibly northwestern Montana and northeastern Washington. This soil is not extensive. MLRAs 9, 43A, and 44A.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Boundary County, Idaho, 1974.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Histic epipedon - the zone from 0 to 9 inches (Ap horizon)

Particle-size control section - the zone from 10 to 40 inches (part of the Oa/C, Oa/Cg, 2Cg1 and part of the 2Cg2 horizon)

*Devoignes soils in Boundary County are formed from calcareous parent material. Devoignes soils in Benewah County are formed from noncalcareous parent material.

The 10/2013 revision reflects a change in drainage class from poorly drained to very poorly drained based on the type location description.

National Cooperative Soil Survey
U.S.A.