18 FIELD OPERATIONS OF THE BUREAU OF SOILS, 1916i 



left in fields retard drifting to some extent. In other parts of the 

 United States, under similar conditions, it has been found advisable 

 to lay off fields in narrow strips, bounded by grass sod. The turn- 

 ing under of manure, straw, and other vegetable matter would lessen 

 injury from drifting, and the growing of green cover crops to be 

 turned under would also be of benefit in maintaining the productive- 

 ness of the soil. Eape or millet could well be sown in corn fields at 

 the last cultivation, as such seeding would add to the cOrn-stubble 

 pasturage following corn harvest, in addition to lessening the ex- 

 posure of the soil to wind erosion. 



MIAMI LOAM. 



The Miami loam consists of a gray to dark-gray very fine sandy 

 loam to loam, 6 to 10 inches deep, underlain by a brownish-drab to 

 gray clay with brown and greenish mottling. On the surface and 

 throughout the soil to a depth of several feet there are usually pre- 

 sent more or less small gravel, coarse gravel, and bowlders. To a 

 depth of about 3 feet this coarse material is almost entirely of crystal- 

 line-rock origin, those of limestone origin that may have been pre- 

 sent in earlier geologic time probably having been disintegrated and 

 the lime leached away. In some places, however, the clay, gravel, 

 and larger rounded stones in the lower subsoil are calcareous. The 

 substratum is invariably strongly calcareous. 



In the lower lying situations contiguous to the Miami fine sandy 

 loam there has been some modification by overwash from the out- 

 wash plain area, and fine sand and very fine sand have been mixed 

 with the soil to such a degree that it is hard to distinguish the type 

 in places from the fine sandy loam. 



The Miami loam occurs in close association with the Miami fine 

 sandy loam, fairly well removed from the outwash-plain area. It 

 is developed in the southeastern parts of Columbus, Centerville, and 

 Fridley Townships. In general it has a plainlike, level to gently 

 rolling surface. In the southern part of Centerville Township and 

 over most of the type in Fridley Township the surface is more hilly 

 and knolly. With very few exceptions, the type has good surface 

 drainage and underdrainage, and is retentive of moisture. 



The Miami loam is an important type agriculturally. It is natu- 

 rally strong and productive. Ninety per cent or more of its area 

 is in cultivation, the remainder consisting of woodlots. Corn, oats, 

 clover, other tame grasses, and potatoes are the most important 

 crops on this type. It is one of the best soils in the county for dairy- 

 ing, and a large part of the grain and hay grown is fed to dairy 

 cattle. Part of the corn is used for silage, which helps to keep the 

 milk production miiform throughout the year. Hogs are largely 



