LOCATION EVA                     KS+OK

Established Series
Rev. CEW-TCB-SLM
04/2016

EVA SERIES

The Eva series consists of very deep, somewhat excessively drained, moderately rapid permeable soils formed sandy eolian deposits of Holocene age. These soils are on very gently to strongly sloping dunes and plains of the Southern High Plains, northern part (MLRA 77A). Slope ranges from 1 to 9 percent. Mean annual air temperature is about 13 degrees C (57 degrees F), and mean annual precipitation is about 460 mm (18 in).

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Aridic Haplustalfs

TYPICAL PEDON: Eva loamy fine sand - on a 2 percent convex slope in native rangeland, at an elevation of approximately 1061 m (3481 ft). (Colors are for dry soil unless otherwise stated.)

A--0 to 13 cm (0 to 5 in); brown (10YR 5/3) loamy fine sand, brown (10YR 4/3) moist; weak fine granular structure; slightly hard, friable, nonsticky and nonplastic; common fine and medium roots; noneffervescent; neutral, pH 6.7; clear smooth boundary. (Thickness of the A horizon is 10 to 25 cm [4 to 10 in])

BA--13 to 33 cm (5 to 13 in); brown (10YR 5/3) loamy sand; brown (10YR 4/3) moist; weak fine subangular blocky structure; soft, friable, nonsticky and nonplastic; common fine and medium roots; medium low continuity interstitial pores; noneffervescent; moderately alkaline, pH 8.0; gradual smooth boundary. (Thickness of the BA horizon is 0 to 25 cm [0 to 10 in])

Bt1--33 to 46 cm (13 to 18 in); yellowish brown (10YR 5/4) fine sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common fine and medium roots; fine and medium moderate continuity tubular pores; very few faint clay films on surfaces of peds; noneffervescent; moderately alkaline, pH 8.1; gradual smooth boundary.

Bt2--46 to 66 cm (18 to 26 in); yellowish brown (10YR 5/4) fine sandy loam; dark yellowish brown (10YR 4/4) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; fine and medium moderate continuity tubular pores; very few faint clay films on surfaces of peds; strongly effervescent; moderately alkaline, pH 8.2; gradual wavy boundary.

Bt3--66 to 84 cm (26 to 33 in); yellowish brown (10YR 5/4) fine sandy loam, dark yellowish brown (10YR 4/4) moist; moderate fine subangular blocky structure; soft, friable, slightly sticky and slightly plastic; common fine roots; fine and medium low continuity tubular pores; very few faint clay films on surfaces of peds; strongly effervescent; slightly alkaline, pH 7.8; gradual wavy boundary.

Bt4--84 to 104 cm (33 to 41 in); yellowish brown (10YR 5/4) loamy sand, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; soft, friable, slightly sticky and slightly plastic; common fine roots; fine and medium low continuity tubular pores; very few faint clay films on surfaces of peds; strongly effervescent; neutral, pH 7.3; gradual wavy boundary. (Combined thickness of the Bt horizon is 25 to 89 cm [10 to 35 in])

BC--104 to 122 cm (41 to 48 in); yellowish brown (10YR 5/4) loamy sand, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; loose, very friable, nonsticky and nonplastic; common fine roots; fine and medium low continuity interstitial pores; strongly effervescent; neutral, pH 7.2; gradual wavy boundary. (Thickness of the BC horizon is 0 to 76 cm [0 to 30 in])

C1--122 to 155 cm (48 to 61 in); yellowish brown (10YR 5/6) sand, dark yellowish brown (10YR 4/6) moist; massive; loose, nonsticky and nonplastic; common fine roots; slightly effervescent; moderately alkaline, pH 8.1; gradual wavy boundary.

C2--155 to 185 cm (61 to 73 in); brownish yellow (10YR 6/6) sand, yellowish brown (10YR 5/6) moist; massive; loose, nonsticky and nonplastic; common fine roots; 1 percent 5 to 20 mm, and 2 percent 20 to 76 mm subrounded quartzite fragments; strongly effervescent; moderately alkaline, pH 8.4; gradual wavy boundary. (Combined thickness of C horizon is 0 to 76 cm [0 to 30 in])

2Btk1--185 to 196 cm (73 to 77 in); strong brown (7.5YR 5/6) fine sandy loam, weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine roots throughout; fine and medium low continuity tubular pores; very few faint clay films on surfaces of peds; common fine calcium carbonate threads between peds; 1 percent 2 to 5 mm, 3 percent 5 to 20 mm, and 6 percent 20 to 76 mm subrounded quartzite fragments; strongly effervescent; moderately alkaline, pH 8.1; gradual wavy boundary. (Combined thickness of the 2Btk horizon is 15 to 51 cm [6 to 20 in})

2Btk2--196 to 203 cm (77 to 80 in); strong brown (7.5YR 5/6) fine sandy loam, dark yellowish brown (10YR 4/6) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common fine roots; fine and medium moderate continuity tubular pores; very few distinct clay films on surfaces of peds; common fine and medium calcium carbonate threads; 1 percent 2 to 5 mm, 1 percent 5 to 20 mm, and 2 percent 20 to 76 mm subrounded quartzite fragments; strongly effervescent; moderately alkaline, pH 8.1.

TYPE LOCATION: Morton County, Kansas; about 3 miles north and 3 miles west of Elkhart; 900 ft (275 m) east and 150 ft (45 m) north of the southwest corner of section 25, Township 34S, Range 43W (Sixth Principal).

USGS topographic quadrangle: Elkhart North, Kansas
Latitude: 37 degrees, 3 minutes, 16 seconds N
Longitude: 101 degrees, 57 minutes, 1.98 seconds W
Datum: NAD83

Decimal Degrees
Latitude: 37.0544434
Longitude: -101.9505539

UTM Easting: 237627 m
UTM Northing: 4104985 m
UTM Zone: 14s

RANGE IN CHARACTERISTICS:
Solum thickness: more than 203 cm (80 in)
Thickness of the ochric epipedon: 8 to 48 cm (3 to 19 in)
Thickness of the argillic horizon: 25 to 180 cm (10 to 71 in)
Depth to secondary calcium carbonate: 152 to 203 cm (60 to 80 in)
Depth to lithologic discontinuity (where present): 120 to 185 cm (47 to 73 in)

Particle-size control section (weighted average):
Silicate clay: 8 to 16 percent

A or Ap horizons:
Hue: 10YR
Value: 4 to 6, 3 to 5 moist
Chroma: 3 or 4
Texture: sand, fine sand, loamy fine sand, or fine sandy loam
Effervescence: none
Reaction (pH): neutral or slightly alkaline (6.6-7.8)

Upper Bt horizons:
Hue: 10YR
Value: 4 to 6, 3 to 5 moist
Chroma: 3 or 4
Texture: sandy loam or fine sandy loam
Effervescence: none to strong
Reaction (pH): neutral to moderately alkaline (6.6-8.4)

Lower Bt horizons:
Hue: 10YR
Value: 4 to 6, 3 to 5 moist
Chroma: 3 or 4
Texture: loamy fine sand, sandy loam, or fine sandy loam
Effervescence: none to strong
Reaction (pH): neutral to moderately alkaline (6.6-8.4)

BC and C horizons:
Hue: 7.5 or 10YR
Value: 5 to 7, 4 to 6 moist
Chroma: 4 to 6
Texture: sand, fine sand, or loamy fine sand
Effervescence: slight or strong
Reaction (pH): neutral to moderately alkaline (6.6-8.4)

2Btk horizons (where present):
Hue: 7.5 or 10YR
Value: 4 to 6, 3 to 5 moist
Chroma: 3 to 6
Texture: fine sandy loam, sandy loam, loam, sandy clay loam, silt loam, or silty clay loam
Coarse fragments: amount-0 to 8 percent; size-gravels; kind-quartzite, feldspar, ironstone, and sandstone
Visible secondary calcium carbonates: amount-0 to 10 percent; kind-coats, and thread-shaped masses
Calcium carbonate equivalent: 0 to 10 percent
Effervescence: slight or strong
Reaction (pH): slightly alkaline to strongly alkaline (7.4-9.0)

COMPETING SERIES: These are the Fragua (NM), Fraguni (NM), Hebbronville (TX), Spantara (TX), Vona (CO), Vonalf (WY), and Xema (WY) soils.
Fragua soils: formed in mixed colluvium, alluvium, and eolian deposits and have rock fragments throughout the soil profile
Fraguni soils: formed in fan alluvium and eolian deposits, occur at higher elevations, have a shorter growing season, and have climax vegetation of pinion and juniper
Hebbronville soils: are in a hyperthermic soil temperature regime
Spantara soils: are in a thermic soil temperature regime
Vona and Vonalf soils: formed in alluvium and eolian sediments and have rock fragments up to 15 percent in the series control section.
Xema soils: are moderately deep over sandstone

GEOGRAPHIC SETTING:
Parent material: sandy eolian sediments of Holocene and late Pleistocene age
Landscape: tablelands
Landform(s): dunes and interdunes on sand sheets
Slope: 1 to 9 percent
Soil moisture: An ustic moisture regime bordering on aridic. The soil moisture control section is dry in some or all parts for more than 180 but less than 205 days, cumulative, in normal years. July through August and December through February are the driest months. These soils are intermittently moist in September through November and March through June
Mean annual air temperature: 12 to 14 degrees C (53 to 57 degrees F)
Mean annual precipitation: 381 to 584 mm (15 to 23 in)
Frost-free period: 162 to 203 days
Elevation: 750 to 1250 m (2460 to 4100 ft)
Thornthwaite annual P-E Indices: 25 to 36

GEOGRAPHICALLY ASSOCIATED SOILS: These are Belfon, Bigbow, Canina, Dalhart, Forgan, Hugoton, Lautz, Optima, and Vorhees series.
Belfon soils: occur on slightly lower landscapes, have a mollic epipedon, and have a fine-loamy particle-size class.
Bigbow and Dalhart soils: occur on slightly lower landscapes, and have a fine-loamy particle-size class.
Canina soils: occur on similar dune landscape positions, have a calcic horizon within 100 cm (40 in) of the soil surface, and have a fine-silty particle-size class.
Hugoton soils: occur on slightly lower landscapes, have a mollic epipedon, and have a fine-silty particle-size class.
Lautz soils: occur on lower playa landscape positions, and have a fine particle-size class.
Optima soils: occur on higher landscape positions, do not have an argillic horizon, and have a sandy particle-size class.
Vorhees soils: occur on similar landscapes, are calcareous to the surface, and have a calcic horizon within 100 cm (40 in) of the soil surface.

DRAINAGE AND PERMEABILITY:
Drainage class: somewhat excessively
Permeability: moderately rapid
Runoff: very low on 1 to 5 percent slopes, and low on 5 to 10 percent slopes

USE AND VEGETATION: These soils are mainly used for rangeland. Some areas are used for irrigated crops. Native vegetation is dominantly sand bluestem little bluestem, sideoats grama, sand lovegrass, sand paspalum, fall witchgrass, and sand dropseed. Sand sagebrush is the major woody species with lesser amounts of skunkbush sumac and yucca.

DISTRIBUTION AND EXTENT: Southwest Kansas and Southeastern Colorado south of the Cimarron River, and the Oklahoma Panhandle (MLRA-77A in LRR H). This soil is moderately extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas

SERIES ESTABLISHED: Morton County, KS, 1996.

REMARKS:
These soils were formerly included in the Vona series.

Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: 0 to 13 cm (0 to 5 in) (A horizon)
Argillic horizon: 33 to 66 cm (13 to 26 in) (Bt1 and Bt2 horizons)
Lithologic discontinuity: 185 to 203 cm (73 to 80 in) (2Btk1 & 2Btk2)

Series revised as part of the SDJR initiative, 2016.
Series revised MLRA-77 Soil Survey; Stevens County, Kansas; 2004.

ADDITIONAL DATA: KSSL lab data available, Lincoln, NE; S1993KS129003 (Morton County, KS); S1992KS189001 (Stevens County, KS); S1984KS175001 (Seward County, KS); S1984OK139002 (Texas County, OK); S1999OK007004 (Beaver County, OK).

Taxonomic Version: Keys to Soil Taxonomy, Twelfth Edition, 2014

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National Cooperative Soil Survey
U.S.A.