48 BULLETIN 142, U. S. DEPARTMENT OF AGRICULTURE. 
average for the counties in which it occurs, since in each case it con- 
stitutes the best wheat soil of the area. A typical field of wheat on 
the Miami clay loam is shown in Plate XII, figure 2. Usually wheat 
is seeded on land upon which corn has been produced the preceding 
year. The winter varieties only are grown, spring wheat being prac- 
tically unknown in this section. In Michigan the area devoted to 
wheat usually exceeds that devoted to any other grain crop on this 
soil type, and the average yields upon all soils in the counties of 
which soil surveys have been made are in the vicinity of 13 bushels 
per acre. The yields reported from this soil type in the same coun- 
ties are 15 to 25 bushels per acre, indicating again that the Miami 
clay loam is a good wheat soil. Complete commercial fertilizers are 
sometimes used with the wheat seeding, but in general the fertilizers 
incorporated with the soil in the preparation of the land for corn are 
chiefly relied upon for the production of the succeeding wheat crop. 
In many cases wheat is produced two years in succession, and grass 
is seeded with the second crop. In other instances oats are seeded 
upon the corn land and followed by wheat. 
The acreage devoted to oats in the counties in which soil surveys 
have been made and in which the Miami clay loam predominates 
is usually subordinate both to the wheat acreage and to the acreage 
in corn, although in some instances the acreage in oats is second only 
to that devoted to corn. For these counties Census statistics indi- 
cate an average yield of over 35 bushels of oats per acre. In In- 
diana the average yields for the Miami clay loam are stated in the 
soil survey reports at 30 to 35 bushels per acre, while in Michigan 
and Ohio the average yields are given as 40 to 60 bushels per acre. 
These estimates are fully verified by an examination of the statistics 
of yields in the counties mapped. As has been noted, oats frequently 
take the place of wheat as a first-year small-grain crop. In other 
instances, particularly in Michigan and the northern part of Ohio, 
the wheat is entirely displaced by oats, which are seeded only for a 
single year, being immediately followed by grass. 
The area devoted to grass growing and hay production in the 
counties in which the Miami clay loam is the dominant soil type 
almost equals the area devoted to the production of the grain crops. 
This is due to the fact that grass usually occupies the ground for 
two or three years in the regular rotation, being cut for hay during 
the first and second years and not infrequently pastured the third 
year preparatory to breaking the ground for corn. The average 
yields for the counties in which soil surveys have been made exceeds 
1.3 tons of hay per acre, and again the Miami clay loam may be 
credited with a yield greater than the average for these counties. 
On this type the yields range from 1 to 2 tons per acre, and the 
latter yield is sometimes exceeded. In all areas where the Miami 
