LOCATION MARKSBUTTE COEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Fluvaquentic Haplustolls
TYPICAL PEDON: Marksbutte fine sandy loam, (Colors are dry unless otherwise stated)
A1--0 to 6 inches, (0 to 15cm); grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak coarse granular structure and moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; moderately alkaline, strongly effervescent; clear smooth boundary. (4 to 10 inches thick)
A2--6 to 13 inches, (15 to 33cm); grayish brown (10YR 5/2) fine sandy loam; dark brown (10YR 3/3) moist; weak medium subangular blocky structure parting to moderate fine granular structure; soft, very friable, slightly sticky and nonplastic; moderately alkaline, strongly effervescent; clear smooth boundary. (0 to 8 inches thick)
C1--13 to 27 inches, (33 to 69cm); pale brown (10YR 6/3) fine sandy loam; brown (10YR 5/3) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; moderately alkaline, strongly effervescent; clear wavy boundary. (6 to 20 inches thick)
C2g--27 to 33 inches, (69 to 84cm); light brownish gray (2.5Y 6/2) loamy sand; dark grayish brown (2.5Y 4/2) moist; few fine faint strong brown (7.5YR 5/6) mottles; single grained; loose when dry and moist; nonsticky and nonplastic; moderately alkaline, strongly effervescent; gradual smooth boundary. (0 to 7 inches thick)
2C3g--33 to 41 inches, (84 to 104cm); light gray (2.5Y 7/2) coarse sand; light brownish gray (2.5Y 6/2) moist; many fine distinct dark gray (N 4/0) and few fine prominent reddish brown (5YR 5/4) mottles; single grained; loose when dry and moist; nonsticky and nonplastic; moderately alkaline, slightly effervescent; gradual smooth boundary. (0 to 11 inches thick)
2C4g--41 to 60 inches, (104 to 152cm); light brownish gray (2.5Y 6/2) loamy fine sand, olive (5Y5/3) moist; many medium prominent dark gray (N 4/0) and few medium prominent pale yellow (2.5Y 8/2) mottles; structureless; loose dry and moist, nonsticky and nonplastic; three continuous lenses (1 to 4 cm. thick) of coarse sand or gravelly sand; moderately alkaline, slightly effervescent. (0 to 16 inches thick)
TYPE LOCATION: Sedgwick County, Colorado; 800 feet north and 700 feet east of the southwest corner of Sec. 12, T. 11 N., R. 46 W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 53 degrees F. Throughout the soil profile organic carbon irregularly decreases with increasing depth. Depth to gleying or low chroma mottles ranges from 22 to 36 inches. Clay percentage of the particle-size control section ranges from 8 to 18 percent. Coarser-textured lenses of coarse sand or fine gravel, less than 4 cm. thick, occur below 28 inches in depth. The mollic epipedon is 10 to 16 inches thick.
The A horizons have a hue of 10YR, value of 4 or 5 dry, 2 or 3 moist, chroma of 1 through 3. Reaction is mildly or moderately alkaline.
The C and 2C horizons have hues of 10YR, 2.5Y or 5Y, values of 5 through 8, chroma of 0 through 4. Reaction is moderately or strongly alkaline.
COMPETING SERIES: These are the Alda (NE), Novina (NE), Ovina (NE), Sunset (UT), and Wann (NE) series. The Alda series may be saturated longer than 90 days during the growing season and the salinity is less than 4 mmhos throughout. Novina, Ovina, and Wann soils lack the coarse sand or gravelly sand above a depth of 40 inches. Sunset soils have a xeric moisture regime.
GEOGRAPHIC SETTING: Marksbutte soils are on bottom lands or low terraces. Slopes are 0 to 3 percent. They formed in stratified alluvium. The mean annual temperature is from 48 to 56 degrees F., and the mean annual precipitation is 15 to 18 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Wann, McCook, and Las soils. The Wann soils lack coarse sand above the 40-inch depth. Las and McCook soils have more than 18 percent clay in the particle-size control section.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow runoff; the permeability in the upper 33 inches is moderately rapid and rapid below 33 inches.
USE AND VEGETATION: These soils are cultivated or in improved grass hay or pasture conditions. Much of the area is irrigated. Corn, sugar beets, alfalfa, and dry edible beans are the main crops grown. Inland saltgrass, switchgrass, alkali sacaton, and alkali cordgrass are the dominant native species.
DISTRIBUTION AND EXTENT: Northeastern Colorado and southwestern Nebraska. The Marksbutte series is of minor extent with about 7,000 acres in Sedgwick County.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Sedgwick County, Colorado; 1990.
REMARKS: Last updated by the state 10/90. The name is taken from a prominent hill in Sedgwick County. This series should replace the soil named Alda Variant in the Washington County Soil Survey, 1986. Diagnostic features include a mollic epipedon at 0 to 13 inches.