Peat and its Uses as Fertilizer and Fuel

Footnotes:

[1] The great Dismal Swamp is a grand peat bog, and doubtless other of the swamps of the coast, as far south as Florida and the Gulf, are of the same character.

By the general term Peat, we understand the organic matter or vegetable soil of bogs, swamps, beaver-meadows and salt-marshes.

It consists of substances that have resulted from the decay of many generations of aquatic or marsh plants, as mosses, sedges, coarse grasses, and a great variety of shrubs, mixed with more or less mineral substances, derived from these plants, or in many cases blown or washed in from the surrounding lands.

2. The conditions under which Peat is formed.

In this country the production of Peat from fallen and decaying plants, depends upon the presence of so much water as to cover or saturate the vegetable matters, and thereby hinder the full access of air. Saturation with water also has the effect to maintain the decaying matters at a low temperature, and by these two causes in combination, the process of decay is made to proceed with great slowness, and the solid products of such slow decay, are compounds that themselves resist decay, and hence they accumulate.

In the United States there appears to be nothing like the extensive moors or heaths, that abound in Ireland, Scotland, the north of England, North Germany, Holland, and the elevated plains of Bavaria, which are mostly level or gently sloping tracts of country, covered with peat or turf to a depth often of 20, and sometimes of 40, or more, feet. In this country it is only in low places, where streams become obstructed and form swamps, or in bays and inlets on salt water, where the flow of the tide furnishes the requisite moisture, that our peat-beds occur. If we go north-east as far as Anticosti, Labrador, or Newfoundland, we find true moors. In these regions have been found a few localities of the Heather (Calluna vulgaris), which is so conspicuous a plant on the moors of Europe, but which is wanting in the peat-beds of the United States.

In the countries above named, the weather is more uniform than here, the air is more moist, and the excessive heat of our summers is scarcely known. Such is the greater humidity of the atmosphere that the bog-mosses,--the so-called Sphagnums,--which have a wonderful avidity for moisture, (hence used for packing plants which require to be kept moist on journeys), are able to keep fresh and in growth during the entire summer. These mosses decay below, and throw out new vegetation above, and thus produce a bog, especially wherever the earth is springy. It is in this way that in those countries, moors and peat-bogs actually grow, increasing in depth and area, from year to year, and raise themselves above the level of the surrounding country.

Prof. Marsh informs the writer that he has seen in Ireland, near the north-west coast, a granite hill, capped with a peat-bed, several feet in thickness. In the Bavarian highlands similar cases have been observed, in localities where the atmosphere and the ground are kept moist enough for the growth of moss by the extraordinary prevalence of fogs. Many of the European moors rise more or less above the level of their borders towards the centre, often to a height of 10 or 20 and sometimes of 30 feet. They are hence known in Germany as high moors (Hochmoore) to distinguish from the level or dishing meadow-moors, (Wiesenmoore). The peat-producing vegetation of the former is chiefly moss and heather, of the latter coarse grasses and sedges.

In Great Britain the reclamation of a moor is usually an expensive operation, for which not only much draining, but actual cutting out and burning of the compact peat is necessary.

The warmth of our summers and the dryness of our atmosphere prevent the accumulation of peat above the highest level of the standing water of our marshes, and so soon as the marshes are well drained, the peat ceases to form, and in most cases the swamp may be easily converted into good meadow land.

Springy hill-sides, which in cooler, moister climates would become moors, here dry up in summer to such an extent that no peat can be formed upon them.

As already observed, our peat is found in low places. In many instances its accumulation began by the obstruction of a stream. To that remarkable creature, the beaver, we owe many of our peat-bogs. These animals, from time immemorial, have built their dams across rivers so as to flood the adjacent forest. In the rich leaf-mold at the water's verge, and in the cool shade of the standing trees, has begun the growth of the sphagnums, sedges, and various purely aquatic plants. These in their annual decay have shortly filled the shallow borders of the stagnating water, and by slow encroachments, going on through many years, they have occupied the deeper portions, aided by the trees, which, perishing, give their fallen branches and trunks, towards completing the work. The trees decay and fall, and become entirely converted into peat; or, as not unfrequently happens, especially in case of resinous woods, preserve their form, and to some extent their soundness.

In a similar manner, ponds and lakes are encroached upon; or, if shallow, entirely filled up by peat deposits. In the Great Forest of Northern New York, the voyager has abundant opportunity to observe the formation of peat-swamps, both as a result of beaver dams, and of the filling of shallow ponds, or the narrowing of level river courses. The formation of peat in water of some depth greatly depends upon the growth of aquatic plants, other than those already mentioned. In our Eastern States the most conspicuous are the Arrow-head, (Sagittaria); the Pickerel Weed, (Pontederia;) Duck Meat, (Lemna;) Pond Weed, (Potamogeton;) various Polygonums, brothers of Buckwheat and Smart-weed; and especially the Pond Lilies, (Nymphoea and Nuphar.) The latter grow in water four or five feet deep, their leaves and long stems are thick and fleshy, and their roots, which fill the oozy mud, are often several inches in diameter. Their decaying leaves and stems, and their huge roots, living or dead, accumulate below and gradually raise the bed of the pond. Their living foliage which often covers the water almost completely for acres, becomes a shelter or support for other more delicate aquatic plants and sphagnums, which, creeping out from the shore, may so develop as to form a floating carpet, whereon the leaves of the neighboring wood, and dust scattered by the wind collect, bearing down the mass, which again increases above, or is reproduced until the water is filled to its bottom with vegetable matter.

It is not rare to find in our bogs, patches of moss of considerable area concealing deep water with a treacherous appearance of solidity, as the hunter and botanist have often found to their cost. In countries of more humid atmosphere, they are more common and attain greater dimensions. In Zealand the surfaces of ponds are so frequently covered with floating beds of moss, often stout enough to bear a man, that they have there received a special name "_Hangesak_." In the Russian Ural, there occur lakes whose floating covers of moss often extend five or six feet above the water, and are so firm that roads are made across them, and forests of large fir-trees find support. These immense accumulations are in fact floating moors, consisting entirely of peat, save the living vegetation at the surface.