28 FIELD OPERATIONS OF THE BUREAU 01 SOILS, 1918. 



CLINTON SILT LOAM. 



Clinton silt loam consists of a lij^ht-yellowish or grayisli-bro%vn to 

 buff, velvety silt loam, extending to a depth of 12 inches and under- 

 lain by a moderately friable silty clay loam. In the lower subsoil 

 a very faint gray mottling is sometimes observed. In several places 

 particularly in the vicinity of Bethel Church, numerous patches, too 

 small to map separately, of fine sandy loam are encountered. In 

 the southeast corner of sec. 15, T. 75 N., R. 4 W., a small area of 

 the type occupies a rather level position below the general elevation 

 of the upland plain, somewhat resembling a terrace. The type is 

 derived from the same loess formation as the other loessial types, 

 but differs from them in physical properties and in topography. 

 Owing to the pronounced surface relief and the consequent better 

 aeration, the subsoil is more oxidized and unmottled, while the 

 color of the surface soil is lighter, owing to the forest growth, which 

 prevented such an accumulation of organic matter as character- 

 izes most of the prairie soils. The type is locally referred to as 

 "mulatto" soil. 



• The Clinton silt loam is well distributed over both the east and 

 west upland. It occurs near the edge of the bluffs and main drain- 

 age ways of recent development, where the draws are steep and V- 

 shaped. It generally occurs between the Tama, Grundy, or Musca- 

 tine soils and the Lindley, terrace, or first-bottom soils in an irregu- 

 lar strip, varjrLng from a fraction of a mile to 2 or 3 miles in width. 

 Frequently it merges gradually with the Tama silt loam, so that 

 the division between the two types is rather arbitrary. This is 

 particularly true 1^ and 2^ miles north of Cotter. 



The type is steeply rolling to broken, though including some level 

 areas between hollows, and is well drained. It is quite important 

 agriculturally, the greater part being in cultivation and the remainder, 

 aside from that used for lots and building sites, in pasture, generally 

 woods pasture. All of the type was originally forested, the growth 

 consisting of white oak, post oak, black oak, shagbark hickory, elm, 

 ash, hawthorn, and elderberry. 



This soil is used for all the farm crops commonly grown, mainly 

 wheat, rye, oats, corn, and hay. It is preeminently a wheat soU, as 

 wheat seems to be better adapted to it than any other crop. Rye is 

 grown more extensively than on any other upland type. Corn, while 

 quite generally grown, does not yield as heavily tis on the other dark- 

 surfaced upland types. The different branches of live-stock farming 

 are fairly well developed on this soil. Corn yields 25 to 50 bushels 

 per acre with an average of 35 bushels; oats, 30 to 60 bushels, with 

 an average of 35 bushels; hay, one-half ton to 1^ tons, averaging 

 three-fourths ton; winter wheat, 15 to 45 bushels, averaging about 

 28 bushels; spring wheat, 10 to 40 bushels, averaging about 22 



