LOCATION FARRAR IA+MNEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Hapludolls
TYPICAL PEDON: Farrar fine sandy loam-on a convex slope of 3 percent gradient, cultivated. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 6 inches; very dark brown (10YR 2/2) fine sandy loam, dark grayish brown (10YR 4/2) dry; weak fine granular structure; very friable; slightly acid; abrupt smooth boundary. (5 to 9 inches thick)
A1--6 to 9 inches; very dark brown (10YR 2/2) fine sandy loam, dark grayish brown (10YR 4/2) dry; weak medium granular structure; very friable; medium acid; clear smooth boundary. (3 to 4 inches thick)
A2--9 to 14 inches; very dark grayish brown (10YR 3/2) fine sandy loam, grayish brown (10YR 5/2) dry; weak medium subangular blocky structure; very friable; medium acid; clear smooth boundary. (4 to 6 inches thick)
Bw1--14 to 22 inches; brown (10YR 4/3) fine sandy loam; weak medium subangular blocky structure; very friable; slightly acid; clear smooth boundary. (6 to 17 inches thick)
2Bw2--22 to 26 inches; brown (10YR 4/3) loam; weak medium subangular blocky structure; friable; few pebbles; neutral; clear smooth boundary. (4 to 18 inches thick)
2BC--26 to 29 inches; dark yellowish brown (10YR 4/4) loam; weak coarse subangular blocky structure; friable; few pebbles; neutral; clear smooth boundary. (0 to 6 inches thick)
2C--29 to 60 inches; yellowish brown (10YR 5/4) and light olive brown (2.5Y 5/4) loam; massive; friable; few pebbles; few soft calcium carbonate concretions in the upper part; strong effervescence; mildly alkaline.
TYPE LOCATION: Polk County, Iowa; about 2 miles west of Farrar; 1,220 feet north and 50 feet west of the southeast corner of sec. 21, T. 81 N., R. 22 W.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 24 to 50 inches and corresponds to the depth to carbonates. Thickness of material I ranges from 18 to 36 inches. The most acid part of the profile is the A horizon and upper B horizon which are slightly or medium acid.
The A horizon has hue of 10YR, value of 2 or 3, and chroma of 1 or 2. In some pedons, a dark brown (10YR 3/3) BA horizon is present.
The Bw horizon has hue of 10YR or 7.5YR, value of 4 or 5, and chroma of 3 or 4. It commonly is fine sandy loam but layers of loamy fine sand less than 6 inches are in some pedons.
The 2Bw horizon has hue of 10YR, value of 4 or 5, and chroma of 3 to 6. It is loam with 18 to 24 percent clay. The weighted average clay content of the control section ranges from 18 to 22 percent.
The 2C horizon has hue of 10YR or 2.5Y, value of 4 to 6, and chroma of 4 or 6. Mottles with chroma of 1 to 8 are present below 30 inches in some pedons.
COMPETING SERIES:: These are the Arbor, Aredale, Bode, Clarion, Cresken, Everly, Frontenac, Garmore, Kenyon, Liscomb, Moland, Ocheyedan, Ostrander, and Rossfield series in the same family and the Ankeny, Ayr, Dickinson, Dunnville, Grogan, and Lomax soils. The Arbor, Aredale, Bode, Clarion, Cresken, Everly, Frontenac, Garmore, Kenyon, Liscomb, Moland, Ocheyedan, Ostrander, and Rossfield soils all have higher clay and lower sand content in the A and upper part of the B horizons. Ankeny, Dickinson, Dunnville, Grogan, and Lomax soils are leached of carbonates to greater depths. Ayr soils have argillic horizons and more clay in the B horizons.
GEOGRAPHIC SETTING: Farrar soils are on convex, slightly undulating summits of interfluves and convex side slopes adjacent to major streams and their tributaries. Slope gradients range from 0 to 30 percent. They formed in about 2 feet of oxidized-leached fine sandy loam eolian material and oxidized-leached and unleached loam Wisconsin glacial till. Mean annual temperature ranges from about 45 to 52 degrees F, and mean annual precipitation ranges from about 30 to 32 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Ankeny, Clarion, and Dickinson soils and the Spillville and Storden soils. Ankeny and Spillville soils are downslope on foot slopes and alluvial fans. Spillville soils have thicker mollic epipedons and clay content of the B horizon exceeds 18 percent. Clarion soils are on similar landscape positions. Dickinson soils are on uplands at higher elevations. Storden soils typically are on the more sloping landscapes and have calcareous sola.
DRAINAGE AND PERMEABILITY: Well drained. Surface runoff is medium. Permeability is moderately rapid in the upper part and moderate in the lower part.
USE AND VEGETATION: These soils commonly are used for cultivated crops. Corn, soybeans, small grain, and legume hay are grown. Native vegetation was tall prairie grasses.
DISTRIBUTION AND EXTENT: Central and north central Iowa in the Wisconsin till area and possibly in Minnesota. They are inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Polk County, Iowa, 1958.
REMARKS: Diagnostic horizons and features recognized in this pedon are mollic epipedon - The zone from the surface of the soil to a depth of 14 inches (Ap, A1, and A2 horizons); Cambic horizon - the zone from a depth of 14 to 29 inches (Bw1, Bw2, and 2BC horizons); Udic moisture regime.