26 BULLETIN 802, U. S. DEPARTMENT OF AGRICULTURE. 
profitably employed for various uses, including those essential to 
agriculture and as powdered 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 nitrifying 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 (Phragmites 
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 type 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 surface 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. 
