12 BULLETIN 1419, U. S. DEPARTMENT OF AGRICULTURE 
• 
of fibrous, or of woody layers of peat; the units of the second group 
represent different forms of combinations from these chief layers. 
Areas of peat land with a profile showing the same composition of 
sedimentary peat materials throughout; as in cross section 1 of Plate 
1, were formed in deep water. The areas undoubtedly represent the 
precipitation of organic material which previously floated or was 
suspended in the water. Together with mineral matter the fine- 
textured plant and animal remains settled as a dark-brown to black- 
ish plastic peat material more or less gelatinous. It contains 
occasionally an admixture of less disintegrated fibrous or woody 
components which tend to give an open texture to the layer. The 
presence of large quantities of diatoms and sponge spicules may cause 
a burning and itching sensation in men and animals when this type 
of peat layer is plowed and cultivated. The sharp-pointed, siliceous 
material has a polishing and abrading effect on tools and implements. 
Peat lands of the sedimentary group are water-logged, often having 
excessive slopes and unfavorable adjacent topography. They lack 
firmness and stability under loads, increase the expense of drainage, 
and so decrease the profit of operation. Areas of a depth greater 
than 5 feet are relatively nonagricultural land; they may be set 
aside as reserves, for water-storage basins, or for wild life. Shallow 
deposits and those with a more favorable combination of layers, indi- 
cated, for example, by cross sections 1-2-1 and 2-1 in Plate 1, might 
serve as wild hay or as wiregrass marshes. If they can be drained 
moderately and furnish merchantable timber, as illustrated by 
profiles 1-3 and 1-2-3 of Plate l,the growth of forest trees may 
possibly be more remunerative. It is of the greatest importance to 
retain the forests already on peat land for natural reproduction and 
gradually to clear away the poor growth by successive thinnings or 
improvement cuttings. 
Peat lands with a cross section as at 2 in Plate 1 consist of brown 
or yellow-brown, raw, coarsely fibrous to felty peat material, only 
slightly disintegrated and more or less acid. Areas of this kind were 
developed under marshy conditions; the level of the ground water 
became elevated with the accumulation of plant remains or fluctu- 
ated moderately during wet and dry periods. This type of peat 
land can withstand considerable pressure where conditions require 
a cover of sand for cranberry growing or a roadbed for highway 
traffic. To be profitable, the areas of uniformly loose, fibrous com- 
position demand deep fall plowing, freezing, and moderate drain- 
age with a well-controlled water level. The resistance of the peat 
material to bacterial decomposition may give rise to an unfavorable 
action on plant growth for a long period of time. For that reason 
seeding and artificial planting of seedlings should not begin too soon 
following drainage; it should be delayed one to two years until the 
surface layer has begun to decompose and the peat soil has reached 
the tilth or ripened stage. 
The differing fertility in this type of peat land may be due also to 
the mineral substratum or to other little-known factors confined to 
the area. Partly disintegrated and more carbonized, dark-colored 
phases of these type units, as well as areas with the cross sections 
2-1-2, 1-3-2, and 3-1-2 in Plate 1, are preferred for the growth of 
the principal root and forage-producing crops, for temporary pas- 
ture, and in some cases for small grains. Regardless of the special 
