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Fibrous layers of peat, shown in Plates 4 and 4, “arelpotous. andy
more or less resistant; they stand up well in verti iBwallod dlls:
and excavations, yielding slowly to frost action an “dpoom positions
Inthe profile series of Plate 1 the layers are Gesignatedby, the digit,
2. Plate 4, A, shows an air-dry sample of rusty brow [AABrgat
hypnum peat, spongy and poorly decomposed. The outltnt=vf the
plant remains is fairly clear and distinct, and the material contains
scarcely any of the altered nonfibrous fraction of organic material
which is characteristic of more advanced stages of disintegration.
Plate 4, B represents a dark-brown hypnum peat, partly disintegrated,
in which the individual plants and their structure are more or less
discernible to the eye. Plate 4, OC, illustrates the side view of an ajr-
dry sample of hypnum peat, reddish to yellowish brown, partly fibrous,
resting on a layer of fine-textured sedimentary peat with shells.
Distinguishing characteristics of sphagnum peat are shown in Plate 4.
D. The material is light brown, coarsely fibrous, spongy, and most of
the plant remains are very well preserved. In Plate 4, E the character-
istic structure of the sphagnum mosses is still recognizable, and in Plate
4, FY, the brown air-dry sphagnum peat shows crumbly texture, owing
to the more advanced stage of disintegration. The proportion of the
ingaompossd “crude-fiber” fraction of organic matter is still rather
high in this material.
Varieties of sedge and reed peat are shown in Plate 5: A, Sedge
muck from a dark-brown, disintegrating fibrous sede peat, after one
year of cultivation under natural field conditions; B, typical sample
of the dark-brown, finely fibrous, felty sedge peats, showing radi-
cellate structure; C, an air-dry, brown, coarsely fibrous, s ongy sedge
peat, poorly decomposed, representing the underground stems and
roots of sedges which spread over a lake or pond after having floated
aS & mat of varying thickness on the surtace of .the water; D, a
blackish brown, well-disintegrated reed peat, granular after five
years under cultivation. It will be noted that the proportion of the
altered nonfibrous fraction of organic material is very large in this
reed muck. The underground untilled portion of a reed peat is
shown in Plate 5, E. This material represents a dark-brown, partly
fibrous reed peat in which the plant remains are more or less clearly
discernible. Fungal hyphe are often present, but they form an unim-
portant proportion of the mass. It is not uncommon, however, to
find a still more fibrous material at lower depths below the surface.
Plate 5, F, represents a yellow-brown, coarsely fibrous reed peat,
rather spongy and very poorly decomposed. The material is easily
identified by the characteristic structure of the nodes and its Wavy
internodes.
It is not generally understood that fibrous layers of peat, whether
derived from mosses (pl. 4, 4 and D) or from the roots and under-
ground stems of sedges and reeds (pl. 5, Cand F), should be subjected
to maceration or to the alternation of moisture and moderate drying.
Such layers must be changed to muck and humus stages by means
of aeration, freezing, and the activity of microorganisms. Variations
in the content of finely fibrous, felty, or carbonized material and
mixtures of fibrous with sedimentary peat tend to hasten decay,
whereby favorable biochemical reactions for plant growth are created.
A very serious problem is presented by the blowing of the dustlike
surface muck derived from decomposing mixed and fibrous types of
soa
SELECTION OF PEAT LANDS FOR DIFFERENT USES
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