LOCATION KIRKHAM UTEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Fluvaquentic Haploxerolls
TYPICAL PEDON: Kirkham silty clay loam--cultivated. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 18 cm; grayish brown (10YR 5/2) silty clay loam, very dark grayish brown (10YR 3/2) moist; weak fine and medium granular structure; very hard, firm, slightly sticky and moderately plastic; many fine roots; few fine and medium pores; strongly effervescent; slightly alkaline (pH 7.6); abrupt smooth boundary. (10 to 20 cm thick)
A--18 to 33 cm; grayish brown (10YR 5/2) silty clay, very dark grayish brown (10YR 3/2) moist; moderate medium angular blocky structure; extremely hard, firm, moderately sticky and moderately plastic; few fine roots; few fine pores; strongly effervescent; slightly alkaline (pH 7.7); clear smooth boundary. (8 to 28 cm thick)
C1--33 to 86 cm; light brownish gray (10YR 6/2) silty clay loam, dark brown (10YR 3/3) moist; massive; very hard, firm, moderately sticky and moderately plastic; few fine roots; many very fine pores; common fine faint dark yellowish brown (10YR 3/4) moist masses of iron accumulation; few fine mollusk shells; violently effervescent; moderately alkaline (pH 8.1); clear smooth boundary. (45 to 115 cm thick)
C2--86 to 132 cm; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; common fine, few medium pores; fine faint dark yellowish brown (10YR 4/4) moist masses of iron accumulation; violently effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (0 to 50 cm thick)
2C3--132 to 173 cm; pale brown (10YR 6/3) fine sandy loam, brown (10YR 4/3) moist; massive; slightly hard, very friable, slightly sticky and nonplastic; few fine pores; common fine faint dark yellowish brown (10YR 4/4) moist masses of iron accumulation; violently effervescent; moderately alkaline (pH 8.3).
TYPE LOCATION: Weber County, Utah; about 0.5 mile north of Warren and 100 feet west of 5900 West Street; approximately 500 feet north and 100 feet west of the east quarter corner of section 1, T. 6 N., R. 3 W.; USGS Plain City 7.5 minute quadrangle; latitude 41 degrees 17 minutes 16 seconds N and longitude 112 degrees 7 minutes 23 seconds W; NAD 83; UTM zone 12N 405960E, 4571304N.
RANGE IN CHARACTERISTICS:
Soil moisture: Moist in winter and spring and continuously dry in all parts for significant periods in summer and fall; xeric soil moisture regime bordering aridic.
Mean annual soil temperature: 8.0 to 12.0 degrees C.
Thickness of the mollic epipedon: 25 to 35 cm.
Effervescence: Strongly effervescent to violently effervescent.
Calcium carbonate equivalent: 5 to 40 percent.
Exchangeable sodium: 5 to 40 percent below depths of 50 cm.
Fluventic features: More than 0.3 percent organic carbon content and an irregular decrease in organic carbon content with depth due to stratification of parent material.
Other features: When this soil is dry in Weber County, many cracks 1 to 5 cm wide extend to depths of 30 to 45 cm.
Particle-size control section - Clay content: Average 20 to 35 percent
A horizon
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 1 to 3, dry or moist.
Organic matter content: 1 to 4 percent.
C horizon
Hue: 10YR or 7.5YR.
Value: 5 to 8 dry, 3 to 6 moist.
Chroma: 2 to 4, dry or moist.
Texture: Silty clay loam, silt loam, or loam; horizons below 100 cm may have stratified texture ranging from sand to silty clay.
COMPETING SERIES: This is the Parehat series. Parehat soils have a calcic horizon.
GEOGRAPHIC SETTING: Kirkham soils are on smooth to undulating flood plains, flood plain steps, lake plains and alluvial fans. Slopes range from 0 to 2 percent. Elevations are 1,280 to 1,740 meters. These soils formed in stratified alluvium derived from quartzite, sandstone, limestone, gneiss, and granite. The climate is dry subhumid. The mean annual precipitation is 200 to 425 mm. The mean annual temperature is 7 to 10.5 degrees C., the mean summer temperature is 18.5 to 22.2 degrees C., and the frost-free period is 100 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Airport and Martini soils. Airport soils have natric horizons and calcic horizons. Martini soils are coarse-loamy.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained or moderately well drained; low or medium surface runoff; moderately slow or slow permeability; moderately low saturated hydraulic conductivity. Endosaturation is present with an apparent seasonal high water table between 50 and 75 cm (shallow or moderately deep free water occurrence classes) between April and August. Cumulative annual duration class is Common. These soils are susceptible to rare flooding for very brief periods year-round or occasional flooding for brief periods between April and June.
USE AND VEGETATION: Kirkham soils are used for livestock grazing, irrigated cropland, and urban development. Drained areas in cropland are used for growing sugar beets, small grains, alfalfa, and improved pasture. These soils are correlated to upland ecological sites in Utah.
DISTRIBUTION AND EXTENT: Northern and west-central Utah. These soils are moderately extensive. MLRA 28A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona.
SERIES ESTABLISHED: Weber County (Davis-Weber Area), Utah, 1967.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 18 cm. (Ap horizon)
Fluventic features - Irregular decrease in organic carbon with increasing depth in the zone from 25 to 125 cm. (C1 and C2 horizons and part of the A horizon)
Aquic conditions - The conditions of endosaturation, reduction, and redoximorphic features between 50 and 75 cm at certain times during normal years. (parts of the C1, C2, and 2C3 horizons)
Particle-size control section - The zone from 25 to 100 cm. (C1 horizon and parts of the A and C2 horizons)
The revision of February 2006 updates the taxonomic class from Fine-silty, mixed, superactive, mesic Fluvaquentic Haplustolls based on the assumed moisture regime being xeric instead of ustic.
ADDITIONAL DATA: The typical pedon at the series type location has partial characterization data by the Soils Laboratory from Utah State University (USU) Logan, UT and is published on pages 140-141, Table 11 of the Soil Survey of Davis-Weber Area, Utah. The pH values in the typical pedon are from saturated paste. The assignment of the cation-exchange activity class is supported by this data.
Previous authors and editors include: RLM-VLP-MJD.