LOCATION MONDOVI                 WA+ID+OR

Established Series
Rev. SMA/RJE
02/2011

MONDOVI SERIES

The Mondovi series consists of very deep, well drained soils formed in recent alluvium on flood plains of intermittent streams and small perennial streams. Slopes are 0 to 8 percent. The average annual precipitation is about 17 inches, the mean annual temperature is about 48 degrees F.

TAXONOMIC CLASS: Coarse-silty, mixed, superactive, mesic Cumulic Haploxerolls

TYPICAL PEDON: Mondovi silt loam-cultivated. (Colors are for moist soil unless otherwise stated)

Ap--0 to 10 inches; very dark brown (10YR 2/2) silt loam, dark grayish brown (10YR 4/2) dry; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine roots; slightly alkaline (pH 7.6); abrupt smooth boundary. (6 to 13 inches thick)

A1--10 to 33 inches; very dark brown (10YR 2/2) silt loam, dark grayish brown (10YR 4/2) dry; massive; slightly hard, friable, slightly sticky and slightly plastic; common fine and very fine roots; few fine and very fine pores; slightly alkaline (pH 7.4); abrupt smooth boundary. (8 to 32 inches thick)

A2--33 to 60 inches; very dark brown (10YR 2/2) silt loam, dark grayish brown (10YR 4/2) dry; massive; slightly hard, friable, slightly stick and slightly plastic; common fine and very fine roots; slightly alkaline (pH 7.4).

TYPE LOCATION: Whitman County, Washington; About 1.9 miles south of the town of Thera, Wa. 2,500 feet north and 2,400 feet west of the southeast corner of section 5, T. 16 N., R 42 E.; USGS topographic quadrangle; Thera, WA.
(Latitude - 46 degrees, 54 minutes, 25 seconds N. and Longitude - 117 degrees, 33 minutes, 8.9 seconds W.) NAD 83.

RANGE IN CHARACTERISTICS: The thickness of the mollic epipedon and depth to contrasting material is more than 40 inches and commonly exceeds 5 feet. The mean annual soil temperature is 47 to 54 degrees F. These soils are usually moist, but are dry in all parts between 4 and 12 inches for 60 to 75 consecutive days. The control section is silt loam with 10 to 18 percent clay and 70 to 80 percent silt.
The Ap horizon has chroma of 1 or 2 moist or dry. It has weak or moderate granular structure. It is slightly alkaline to slightly acid.
The A horizon, to a depth of at least 40 inches, has value of 2 to 4 dry, 2 or 3 moist, and chroma of 1 or 2 moist or dry. Below 40 inches the value is 3 to 5 dry and chroma is 1 to 3 dry or moist. It is slightly alkaline or neutral.

COMPETING SERIES: These are the Covello, Hermiston, Onyx, Pedigo, Powder and Touchet series.
Covello soils calcareous in the lower part of the particle-size control section; are moderately alkaline or strongly alkaline throughout; are somewhat poorly drained
Hermiston soils calcareous in the lower part of the particle-size control section; have a mollic epipedon 20 to 30 inches thick; dry for 70 to 90 consecutive days following the summer solstice
Onyx soils dry for 90 to 105 consecutive days; have value of 3 moist, 5 dry in most of the particle-size control section; have a mollic epipedon 20 to more than 40 inches thick
Pedigo soils calcareous throughout; moderately alkaline to very strongly alkaline throughout; have a mollic epipedon 20 to more than 40 inches thick; somewhat poorly drained
Powder soils have an aridic moisture regime; dry for 90 to 120 consecutive days following the summer solstice; have a mollic epipedon 20 to 32 inches thick
Touchet soils dry for 75 to 90 consecutive days following the summer solstice; have redox concentrations at 30 inches or more and are moderately well drained

GEOGRAPHIC SETTING: Mondovi soils are on flood plains and drainageways at elevations of 1,500 to 3,100 feet. The soils formed in silty alluvium from loess washed from the uplands and deposited in narrow tributary stream bottoms. Summers are hot and dry and winters are cold and moist. Average annual precipitation is 15 to 20 inches. Average January temperature is about 28 degrees F, average July temperature is about 68 degrees F. The mean annual temperature is about 45 to 52 degrees F. The average frost-free season is about 110 to 160 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Athena, Caldwell, and Palouse soils, and the competing Covello soils. Athena and Palouse soils have a regular decrease of organic matter with depth. Caldwell soils are more than 18 percent clay. Athena soils are on canyon sides, hills and plateaus. Caldwell and Covello soils are on flood plains. Palouse soils are on hills.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; moderately high saturated hydraulic conductivity. Flooding is rare or occasional.

USE AND VEGETATION: These soils are used mainly for cropland. Common crops are small grains, alfalfa, and grass. Native vegetation was bluebunch wheatgrass, giant wildrye, Idaho fescue, willow, and wild rose.

DISTRIBUTION AND EXTENT: Palouse area of eastern Washington, northeastern Oregon, and northern Idaho; MLRAs 8 and 9. The series is of moderate extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Spokane County, Washington, 1964.

REMARKS: Diagnostic horizons and features recognized in this pedon:
mollic epipedon from the surface to more than 60 inches with an irregular decrease in organic carbon
Particle-size control section from 10 to 40 inches

The type location was moved from Spokane County in 07/2010 to Whitman County after investigations in 2002 and 2005 of the Spokane type location revealed enough volcanic ash influence to meet Vitrandic surbgroup criteria. In addition to the ash influence, Mondovi was a minor component located in a map unit dominated by soils with aquic conditions within 20 inches of the surface. A taxadjunct to the Mondovi series is currently being recognized in Spokane County as: Coarse-silty, mixed, superactive, mesic, Vitrandic Haploxerolls. The Spokane taxadjunct soil is assumed to be Cumulic; however, changes in soil taxonomy recognize the Vitrandic subgroup first.

Further investigation in MLRA 9 is needed to confirm the Cumulic subgroup feature and assess the extent of the influence of volcanic ash and evaluate the presence/absence of an apparent water table.

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National Cooperative Soil Survey
U.S.A.