LOCATION LAWET              NE+SD
Established Series
Rev. MK-LGR-RRZ
10/2002

LAWET SERIES


The Lawet series consists of very deep, poorly drained and very poorly drained soils formed in loamy alluvium on bottom lands. Permeability is moderate or moderately slow. Slopes range from 0 to 2 percent. The mean annual precipitation is about 26 inches, and the mean annual air temperature is about 49 degrees F at the type location.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Calciaquolls

TYPICAL PEDON: Lawet loam with a slope of less than 2 percent in a native meadow. (Colors are for dry soil unless otherwise stated.)

Ak--0 to 10 inches; dark gray (N 4/0) loam, black (10YR 2/1) moist, moderate fine and very fine granular structure; slightly hard, friable; violent effervescence (18 percent calcium carbonate equivalent); moderately alkaline; clear smooth boundary. (7 to 14 inches thick)

ABk--10 to 18 inches; gray (N 5/0) sandy clay loam, very dark gray (10YR 3/1) moist, moderate fine and very fine granular structure; hard, firm; violent effervescence (20 percent calcium carbonate equivalent); moderately alkaline; gradual smooth boundary. (3 to 10 inches thick)

Bk1--18 to 25 inches; gray (N 6/0) sandy clay loam, dark gray (10YR 4/1) moist, moderate fine and very fine granular structure; hard, firm; violent effervescence (20 percent calcium carbonate equivalent); moderately alkaline; clear smooth boundary.

Bk2--25 to 31 inches; gray (5Y 6/1) sandy loam, gray (5Y 5/1) moist, moderate and weak very fine granular structure; slightly hard, very friable; violent effervescence (12 percent calcium carbonate equivalent); moderately alkaline; clear smooth boundary.

Bk3--31 to 55 inches; gray (5Y 6/1) sandy clay loam, gray (5Y 5/1) moist, many medium prominent reddish brown (5YR 4/4) moist mottles; weak medium and very fine subangular blocky structure; slightly hard, firm; small accumulations of lime; violent effervescence (22 percent CaC03 equivalent); moderately alkaline; gradual smooth boundary. (Combined thickness of Bk horizons is 6 to 40 inches)

Cg--55 to 60 inches; light olive gray (5Y 6/2) sandy loam, light greenish gray (5GY 7/1) moist, massive; slightly hard, firm; neutral.

TYPE LOCATION: Pierce County, Nebraska; about 2 miles west and 2 miles north of Foster; 2130 feet south and 130 feet west of the northeast corner, section 19, T. 27 N., R. 3 W.

RANGE IN CHARACTERISTICS:
Soil moisture: Lawet soils are saturated in most parts of the soil moisture control section. They are moist in some part of the soil moisture control section for more than 90 cumulative days in the 120 days following the summer solstice
Depth to secondary carbonates: Typically at or very near the surface of the soil
Depth to redoximorphic features: Iron concentration which are distinct or prominent with hues of 5YR or 7.5YR, value of 3 to 5, and chroma of 3 to 6 are above 40 inches
Depth to endosaturation: 0 to 24 inches from surface of the soil
Thickness of the mollic epipedon: 7 to 24 inches
Thickness of the solum: 16 to 55 inches

A horizon:
Hue: 10YR, 2.5Y or Neutral
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 0 or 1
Texture: typically loam and less commonly very fine sandy loam, fine sandy loam, sandy clay loam, silt loam, and silty clay loam
Calcium Carbonate equivalent: typically 15 to 40 percent, however within 15 inches of the soil surface the calcium carbonate maybe only 12 percent
Reaction: slightly alkaline or moderately alkaline

Bk horizon:
Hue: 10YR, 5Y, 2.5Y or Neutral
Value: 5 to 7 dry, 4 or 5 moist
Chroma: 0 to 2
Texture: sandy clay loam, clay loam, loam, very fine sandy loam, or silty clay loam
Calcium Carbonate equivalent: 15 to 40 percent
Reaction: It is slightly alkaline or moderately alkaline

Cg horizon:
Hue: 10YR, 2.5Y, 5Y, 5GY, or neutral
Value: 5 to 7 dry, 4 to 7 moist
Chroma: 0 to 2
Texture: sandy clay loam, loam, clay loam, sandy loam, or very fine sandy loam; Coarse textured strata, that contain smaller amounts of calcium carbonate than the finer textured strata, are below a depth of 40 inches in some pedons
Reaction: neutral to moderately alkaline

COMPETING SERIES: These are the Harps, Revere, and Roshe Springs series in the same family. Harps soils have thicker sola and formed in glacial till. Revere soils have less sand in the lower half of the series control section and are formed in glacial till. Roshe Springs soils have a calcium carbonate equivalent ranging from 40 to 80 percent.

GEOGRAPHIC SETTING: Lawet soils are level or nearly level. They are on bottom lands and commonly at the upper end of stream valleys in sand-loess transition areas. Slope gradients range from 0 to 2 percent. Lawet soils formed in loamy alluvium. The range of mean annual air temperature is 47 degrees to 52 degrees F, and the range of mean annual precipitation is 18 to 30 inches.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Coleridge, Gibbon, Lamo, Lex, Ord, and Orwet soils, which are on similar landscapes. The Coleridge, Gibbon, Lamo, Lex, and Ord soils do not have calcic horizons and are somewhat poorly drained. The Coleridge, Gibbon, and Lamo soils are in the fine-silty family. Lex soils are moderately deep over coarse sand or gravelly sand. Ord soils are in the coarse-loamy family. Orwet soils are in the sandy family.

DRAINAGE AND PERMEABILITY: Typically poorly drained, but some areas are very poorly drained. Runoff is slow. Permeability is moderate or moderately slow. The seasonal high water table in the poorly drained soil ranges from a depth of 0 to 2 feet.

USE AND VEGETATION: Lawet soils are mostly in meadow and pasture. Native vegetation, when in excellent condition, is mainly big bluestem, little bluestem, switchgrass, indiangrass, and prairie cordgrass. Small areas are used as cropland, but in many areas, adequate drainage is difficult to provide.

DISTRIBUTION AND EXTENT: Nebraska. The series is moderately extensive.

MLRA OFFICE RESPONSIBLE: Salina, Kansas

SERIES ESTABLISHED: Pierce County, Nebraska, 1970.

REMARKS: Lawet soils were previously mapped in the Gibbon, Lamo, and Leshara series. A somewhat poorly drained phase has been mapped and will need future investigations for possible new series. Phases recognized to date include drained, wet, ponded, and saline-alkali.
OSD modification RRZ 7/2002: Within 15 inches of the soil surface the calcium carbonate maybe 12 percent

Diagnostic horizons and features recognized in this pedon are: mollic epipedon--the zone from the surface of the soil to a depth of about 18 inches (Ak and ABk horizons); calcic horizon -- the zone from surface of the soil to about 55 inches (Ak, ABk, Bk1, Bk2, and Bk3 horizons).


National Cooperative Soil Survey
U.S.A.