GEOLOGICAL CLASSIFICATION OF SOILS 43 



last named case the beds are more or less independent of 

 topography, and may be fonnd on hillsides as well as in lower 

 lands. 



Cnmnlose materials may be grouped under two heads, peat 

 and muck. The only difference is in their state of decay. 

 In peat the stem and leaf structure of the original plants 

 can still be detected, and identification is quite possible. In 

 muck, however, the plant tissue has lost its identity as such 

 and is merged into a complicated and indefinite mass of 

 orejanic material. 



1 



The composition of peat and muck may be much altered 

 by the washing-in of mineral matter. In some cases the beds 

 may be from 90 to 95 per cent organic, while in other eases, 

 due to this foreign material, the percentage may drop as low 

 as 20 per cent giving a black or swamp marsh mud. 



The analyses given illustrate the composition of some rep- 

 resentative cumulose soils. (See table VI, page 44.) 



Peat and muck are often of large extent^ and become of 

 extreme value when drained, especially if they are near a 

 good market. They are of peculiar value in trucking oper- 

 ations, being adapted to such crops as onions, celery, lettuce, 

 and the like. Usually they must not only be provided with 

 drainage, but must also be treated with fertilizers carrying 



^The term '^muck'' is often used mterchangeably with peat. Teeh- 

 nieally it is best to limit the former term to those peats which are very 

 thoroughly decomposed or contain a high proportion of mineral matter. 

 Chemically muck is often used in reference to soils containing from 20 

 to 50 per cent, of organic matter, while peat is confined to soils in which 

 the amount of organic constituents is above 50 per cent. According to 

 such a definition most cumulose soils are peats instead of muck. The 

 term ''muck'' is so popular, however, that in the United States its use 

 vnll continue in spite of the technical distinctions that have been 

 established. 



^ Alway reports the following figures : 



G-ermany 5,000,000 acres Wisconsin . . . 3,000,000 acres 



Sweden 12,000,000 '' Ohio 175,000 '' 



Minnesota ... 7,000,000 '' Canada 22,000,000 '' 



Alway, P. J.J Agricultural Value and Becla'maUon of Minnesota Peat 

 Soils; Minn. Agr. Exp. Sta., Bui. 188, 1920. 



