44 BULLETIN 142, U. S. DEPAKTMENT OE AGEICULTUKE. 
this is one of the most effective methods of improving the Miami 
clay loam. Particularly where the surface features are level to gently 
undulating, where farm lands are remote from deeply cut stream 
trenches, or where depressions exist over the surface of the type, the 
installation of tile drains is of fundamental importance in the proper 
utilization of this soil. The contrasts in crop yields between>properly 
drained and poorly drained areas of the type, whether this drainage 
is accomplished naturally or through the installation of tile, are 
marked. With adequate drainage the Miami clay loam ranks high, 
not only for the production of winter wheat, oats, and grass, but 
also as a corn-producing soil. On the other hand, where drainage 
is deficient the production of corn and of winter wheat is practi- 
cally impossible, or the yields secured are too small to justify the 
growing of these crops. There are areas of the Miami clay loam, 
particularly in the more eastern States, which, because of poor drain- 
age, have not been cleared and brought under cultivation until 
within the last half century, and then only through the construction 
of open ditches and the installation of systems of tile drainage. Flat 
areas which have not been so treated still produce small crop yields 
where they are farmed and do not possess that wide range of cropping 
possibility which is essential to a well-balanced system of general 
farming. The cost of tile draining a stiff, impervious soil of this 
character, and especially one where the deeper subsoil is likely to 
contain considerable masses of stone or even large bowlders, is rather 
high, ranging from $20 to $30 an acre for the complete drainage of 
entire fields. Nevertheless, when this is considered as an invest- 
ment, adding to the permanent value of the land, it is usually justi- 
fied, not only by the increased yields secured, but also by the rapidly 
increasing value of the land itself. Tile drains to be effective upon 
the Miami clay loam should have considerable internal diameter 
and adequate fall along the ditch line, and should be placed at rather 
frequent intervals and at an average depth of not less than 3 feet. 
These requirements give rise to the rather high cost of adequate 
underdrainage of the type. 
The frequent incorporation of a reasonable amount of organic mat- 
ter in the surface soil is also requisite to maintain or to increase the 
efficiency of the Miami clay loam. The prevailing systems of farm- 
ing upon the type are fairly adequate for this purpose, in that grass 
constitutes an important crop in the regular rotation practiced over 
practically the entire area of this soil. The plowing under of the 
sod in the preparation of the land for corn or other hoed crops 
assists in the maintenance of organic matter in the soil, while the 
keeping of beef cattle and of dairy cows upon the areas of this type 
renders the application of stable manure possible over a large part 
