56 BULLETIN 142, U. S. DEPARTMENT OF AGRICULTTJHE. 
to 180 days, and is also provided with an abundant rainfall, except 
at rare intervals. Corn is generally recognized as the most profitable 
staple crop, and the constant tendency is to increase the acreage 
planted. 
The availability of the Miami clay loam as a corn soil under these 
climatic conditions is well shown by the average yields secured over 
large areas and through periods of many years. The various soil 
survey reports indicate that the range in yield is from 25 to 60 
bushels per acre, with a general average of 40 bushels or more. 
Statistical data confirm these figures, showing an average yield of 
corn of approximately 44 bushels per acre for the western Ohio 
counties where this soil is dominant and of 45.4 bushels per acre for 
similar counties in central Indiana. In each case these yields are 
above the average for the States. While the figures may be a little 
high, due to the inclusion of average yields from excellent corn soils 
found along numerous river terraces and from appreciable areas of 
black upland soils, they are fairly representative of the capabilities 
of the Miami clay loam for corn growing. These average yields are 
only less than those secured from the dark prairie soils of the corn 
belt, occurring immediately to the west of the region where-the Miami 
soils dominate. All evidences of high present yield, increasing 
acreage, and numerous instances of yields considerably in excess of 
the average production indicate that the Miami clay loam is one of 
the most important corn soils of the eastern part of the central corn- 
growing belt. The soil survey reports Consistently indicate that 
portions of the type which either possess good natural drainage or 
which have been tile drained produce corn crops above the average. 
They also show that yields are increased by the practice of a regular 
rotation which includes the production of clover or mixed clover and 
timothy, and that the use of organic manures is essential to the pro- 
duction of high yields of corn. 
The acreage in hay crops is second to that devoted to corn in 
those Ohio and Indiana counties in which the Miami clay loam pre- 
dominates. The average yields of mixed timothy and clover hay 
are 1.4 tons per acre in the Ohio counties and a little over 1.3 tons 
per acre in the Indiana counties. In both cases these yields are above 
the averages for the respective States. The greater part of the hay 
produced consists of mixed timothy and clover, although a large 
amount of clover alone is grown in both these States. 
Oats are third in total acreage in these counties, covering but 
slightly less area than hay. The yields per acre are slightly under 
30 bushels in each State, being less than the State averages. The 
yields of this crop on the Miami clay loam as it occurs in Michigan 
and Wisconsin are higher than in the more southern localities. 
