BULLETIN 
Contribution from the Bureau of Soils, Milton Whitney, Chief. 
December 29, 1914. 
THE MIAMI SERIES OF SOILS. 
By J. A. Bonsteel, Scientist in the Soil Survey. 
INTRODUCTION. 
The Miami series comprises an important group of soils which are 
distinguished by prevailing brown, light-brown, or gray surface soils 
and yellowish-brown or darker brown subsoils. In the heavier mem- 
bers of the series, especially where the natural drainage is not com- 
plete, the deeper subsoils are mottled with shades of brown and 
gray. 
The topography of the different members of the series ranges from 
nearly level or only gently undulating to more rolling and ridged. 
Locally, sharply sloping ridges and small areas in which erosion has 
developed a choppy surface are encountered. By far the greater 
part of the area occupied by the important types of the series is 
best described as gently undulating to moderately rolling. 
The natural drainage over a large part of the territory occupied 
by this series is fair to good. In the more nearly level tracts, par- 
ticularly of the heavier soils, artificial underdrainage is highly 
beneficial. 
In its original condition practically the entire extent of territory 
occupied by the soils of this series was heavily forested with hard- 
woods. Beech was the dominant growth on the more nearly level 
tracts, while sugar maple was most commonly found in the more 
rolling and better drained areas. Associated with these trees were 
walnut, several species of oak, basswood, and elm and ash, the two 
latter in areas where drainage was markedly deficient. 
The soils of the Miami series are all derived from a thick sheet 
of glacial drift which covers the general region of their occurrence, 
extending to depths varying from a few feet to more than 350 feet. 
The deeper subsoils of the Miami series are generally calcareous 
to a varying degree, but it is a common characteristic of practically 
all of the surface soils that they are lacking in lime, and their agricul- 
tural value is generally increased by the addition of this material. 
Note. — This bulletin is of interest to those engaged or desirous of engaging in farming 
In the North Central States. 
55813°— Bull. 142—14 1 
