FORflSTR 



course OF 



The Soils of Tennessee* ' " 



BY C. A. MOOERS. 



INT ROD U CT ION. 



Tennessee upland soils are of residual origin. That is, they were 

 formed where they lie, or nearly so, by the weathering of rock, or of other 

 geological material, similar to that which now underlies them. Each kind 

 of rock or other material gives rise to a definite kind of soil as is evidenced 

 by a certain uniformity of color, texture and plant food supplies. The 

 line of demarkation between these different soils is often surprisingly easy 

 to distinguish. For example, in a valley where the two soils meet, it is 

 frequently possible to stand with one foot on the heavy yellowish-gray soil 

 derived from the Chickamauga limestone and the other on the brown- 

 colored loam, whose origin is the Holston marble. Where the marble out- 

 crops above the blue limestone, the brown loam may be carried down and 

 over the blue limestone and often at such a depth that the latter has no 

 appreciable effect on the surface soil. 



The fact that each geological formation produces a characteristic soil 

 accounts for the remarkable difference in both the fertility and crop adapt- 

 ability of the various areas throughout the State. Poor land may lie in 

 juxtaposition to that whose agricultural value is several times as great, not 

 because of differences in cropping and manuring, but because of some 

 fundamental differences in the rock from which each was derived. 



In this article the geological basis of classification will therefore be fol- 

 lowed for the upland soils. The alluvial soils cover a relatively small area 

 and vary greatly in character, which is governed in a large part by the 

 velocity of the stream current at the time of the deposition, but also by the 

 origin of the water-borne material. 



*Requests often come to the State Geological Survey for information concerning 

 the soils of Tennessee. The large number of surface divisions of the State and of 

 geological formations that have produced its great variety of soils, have made it 

 difficult satisfactorily to comply with these requests. For this reason Professor 

 Mooers, who is the best authority we have on the soils of Tennessee, was requested 

 to prepare this paper. If the reader can have before him, the geological map of the 

 State, published by this Survey, his interest and understanding of the paper will be 

 much greater than it can be without the map. A. H. P. 



