26 BULLETIIT 802, U. S. DEPAKTMEKT OF AGRICULTURE. 



profitably emjployed. for various uses, including those essential to 

 agriculture and as poTvdered peat for fuel in blast burners, for firing 

 steam boilers, and for other purposes. It has not yet been shown 

 conclusively that this material will produce nitrates on a large 

 scale if inoculated with nitrifj'ing microorganisms, but culture 

 beds of these types of peat would probably be preferable to other 

 media (5). 



EEED-GEASS TYPE. 



" Phragmites peat," " Schilftorf." 



Fibrous peat material, consisting mainly of a network of smooth 

 and pustulate rootlets and stout hollow-stemmed, long, flat-pressed 

 rootstocks (closed at the joints) of the tall reed-grass {Plwagmites 

 communis) ; to a less extent are present the plant remains from species 

 of Typha, Phalaris, Glyceria, Carex, or Sparganium. Macerated 

 aquatic debris is found in varying proportions. The material is light 

 yellowish or reddish brown to rusty brown in color; older layers of 

 this type are fairly compact, largely disintegrated, chocolate brown 

 to blackish in color when exposed to the air, and frequently contain 

 charred woody components. They are mottled in appearance when 

 under poor drainage conditions, from infiltration and precipitation 

 of sulphur or iron compounds. 



The ty^Q is more commonly found in peat deposits of the Central 

 and Middle Western States in layers of considerable thickness. 

 As a peat- forming plant Phragmites is well distributed nearly 

 throughout the United States, tolerant to brackish water and to 

 ground waters which contain a variety of injurious mineral impuri- 

 ties in solution. This renders the surface peat soil liable to saline 

 incrustations drawn from the deeper strata; it tends to retard or 

 prevent the appearance of shrub and tree stages of vegetation and 

 may result in injury to deep-rooting crops when the area is brought 

 under cultivation. On some of the deposits overlying pyritous shale 

 or drift derived from pyrite-bearing rock formations the presence of 

 mineral acids may sensibly diminish the cropping value of the land. 

 The accumulation of iron at the sm^face may continue, in part re- 

 placing the plant remains by ferric compounds and nodular concre- 

 tions which vary widely in composition. 



In Tables I and II have been summarized the more noteworthy 

 data of a physical and chemical nature for this type of peat. 



