THE MIAMI CLAY LOAM. 7 



dant but not excessive rainfall. This fact, coupled with the fine tex- 

 ture and dense structure of the soil material itself, limits the best uses 

 of the soil to the production of general farm crops, particularly to the 

 small grains and grasses. Thus the Miami clay loam is a general farm- 

 ing soil rather than a special purpose soil, and the crop adaptations 

 later enumerated will indicate a strong tendency toward the produc- 

 tion of small grains throughout all the regions where the type has 

 been encountered. 



IMPROVEMENT IN SOIL EFFICIENCY. 



Judging from the increased yields of the general farm crops secured 

 upon such tracts as have been adequately tile-drained, this should con- 

 stitute one of the most important methods of improvement of the 

 present condition of 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 funda- 

 mental importance for the proper utilization of this soil. The con- 

 trasts in crop yields between properly drained and poorly drained 

 areas of the type, whether this drainage has been accomplished natu- 

 rally 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 rendered practically impossible, or else the yields 

 secured are too small to justify the production of these crops. There 

 are areas of the Miami clay loam, particularly in the more eastern 

 States where it has been encountered, which because of poor drainage 

 have not been cleared and brought under cultivation until within the 

 last half century and then only through the installation of open ditches 

 and 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 essen- 

 tial 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 liable 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 investment adding to the permanent value 

 of the land, it is usually justified, not only by the increased crops 

 secured, but also by the rapidly increasing value of the land itself. 

 Tile drains to be effective upon the Miami clay loam should have con- 

 siderable internal diameter and adequate fall along the ditch line 

 and should be placed at rather frequent intervals and at an average 



