Sick Soils not Influenced by Parasites 31 



chemically identical. In treating peaty soils it 

 should be remembered that what appHes to one does 

 not generally apply to another. 



Depih of Peat Soils. HopMns, Readhimer, and 

 Fisher^ classify peaty soils according to the depth 

 as follows: 



1. Soils in which the very peaty material extends 

 three or four feet at least, and often to much greater 

 depths. 



2. Soils with one to three feet of peaty material 

 resting on deep sand. 



3. Soils with one to three feet of peaty material 

 resting on rock, usually with some inches of sandy 

 material between the two. 



4. Soils with six inches to three feet of peaty 

 material resting on a clayey subsoil. 



5. Soils with only a few inches resting on the sand. 

 When the peat is about three feet in depth over a 



deep sand subsoil, the land may be lacking in potash. 

 This must then be supplied in the form of potassium 

 salts, or of manure. 



Of the many types of peaty soils, the best for truck- 

 ing are those black deposits which have reached an 

 advanced state of decomposition, are of a fine texture, 

 and have a high ash content. Brown peat of a 

 fibrous nature is not very desirable. Its physical 

 condition is such that the water cannot be properly 

 controlled. 



Treatment oj Peat Soil: Burning. The mistake is 



' Hopldns, C. G., Readhimer, J. E., and Fisher, O. S., Illinois Agr. 

 Expt. Sta. Bid. 157 : 95-131, 1912. 



