1902 Encyclopedia > Agriculture > Manures - Bones

(Part 43)

X. MANURES (cont.)


It is now about sixty years since ground bones began to be used by farmers in the east side of England as a manure for turnips. At first were roughly smashed by hammers and applied in great quantities. By and by mills were constructed for grinding them to a course powder, in which state they continued to be used as a dressing for turnips, at the rate of sixteen to twenty bushels per acre, in all parts of the kingdom and to a very great extent, until the admirable discovery by Baron Liebig of the mode of preparing super-phosphate of lime by dissolving bones in sulphuric acid. We shall not attempt to explain on chemical principles the wonderful superiority of this substances over simple bone-dust in promoting the growth of the turnip plant. What we should o indifferently, by borrowing from others, will be found well done by various accomplished chemists who write specially on these subjects. We can, however, testify from experience to the important fact, that one bushel of bone-dust dissolved by a third of its weight of suplhuric acid is a manure superior in value to four bushels of simple bone-dust. It is not merely, or even chiefly, in the lessened cost at which an acre of turnips can be manured that this superiority lies, but especially in this, that from the extraordinary stimulus given by super-phosphate of lime to newly germinated turnip plants, they usually arrive at the stage when they are fit for thinning form ten to fifteen days earlier than when sown over farm-yard dung or simple bone-dust, or both combined. This shortening of the critical period during which the attacks of the insignificant but dreaded turnip-beetle so often baulk the hopes of the husbandman is an advantage not easily estimated, and one well fitted to inspire him with confidence in the science to which he owes the discovery, and with grateful respect for the eminent discoverer. This powerful effect in quickening the growth of the young turnip plants is possessed in nearly as great a degree by Peruvian guano, when it is supplied with sufficient moisture. In climates and seasons which may be characterized as moist and cool, guano will show best results, whereas in those which are rather hot and dry super-phosphate has the advantage. Accordingly we find guano the comparative favorite in Scotland, and its rival in the drier counties of England.

Guano is believed to encourage a great expanse of foliage, and to be more especially suited for early sowings; and super-phosphate to influence development of bulb, and to deserve the preference for a later seed-time. The obvious inference is that, for the turnip crop at least, these valuable fertilizers should be used in combination; and actual experiment has verified its soundness. The use of them is universal and ever on the increase. They constitute also the standard by which farmer estimate the cost and effects of other purchased manures. The extent to which they are used, their high price, and the facility with which they can be adulterated with comparatively worthless ingredients, have led to almost unparalleled frauds. The adulteration of manures has, in fact, become a regular trade. Had farmers only their bodily scenes to aid them, the detection of this fraud would be difficult --- perhaps impossible. Here, however, they can call the chemist to their aid, with the certainly of ascertaining the real character of the articles which they are invited to purchase. If purchasers of manures would but insist in every instance on getting from the seller an analysis by some competent chemist, and along with it a written warrandice that the stock is of the quality therein indicated, detection and punishment of fraud would be easy. In regard to super-phosphate of lime, the farmer can purchase bone-dust and sulphuric acid and prepare it himself. We conducted this process for several years in the following way: --- A trough was provided 7 feet x 3-4 x 2-10, made of 2 _ inch deal, strongly joined, and secured at the corners by wooden pegs, as iron nails would be corroded by the acid. This holds conveniently 48 bushels of bones. The heap of bone-dust is then gone over with a barley riddle, and the small dust which passes through this is laid aside to be used as a drying materials for the other portion, after it is subjected to the acid. We find that a third part of the bone-dust passes through the riddle. Three bottles, or carboys as they are called, of concentrated acid, averaging 180 lb. each, are then emptied into the trough and mixed with cold water at the rate of 1 _ of water, by measure, to 1 of aid. In practice, the water is poured in first and then the acid. Into this mixture 48 bushels of bones, previously measured and laid close to the trough, are rapidly shoveled by two laborer who will do well to be attired in clothes and shoes past spoiling. So soon as the bones begin to be thrown in, violent ebullition commences. By the time that the whole of the bones are thrown in , there will be barely liquid enough to moisten the last them. The laborers therefore dig down at one end to the trough till they reach the bottom, and then carefully turn back and mix the whole quantity until they reach the other end. The surface is then leveled and covered with a layer of the dry riddling two inches thick. In this state is is allowed to remain for two days, when the trough is emptied, and the same process is repeated until the whole quantity is gone over. When shoveled out of the trough the bones are found to have become a dark-colored paste, still vary warm, and emitting a sweetish smell. While one person throws it out, another adds to it its proportion of dry riddlings, and mixes them carefully. This mass is heaped up in the corner of a shed, and augmented at each emptying of the trough, until the requisite quantity is obtained. After this the mass is carefully turned over several times, at intervals of five or six days, a and is then dry enough for sowing wither by hand or machine. Some prefer moistening the bones with boiling water, and then adding pure acid as they are shoveled into the trough; but by first mixing the acid and water there is greater certainly of all the bones being equally acted upon. There is also great convenience in using the finest portion of the bone-dust for drying the other, as suitable material for this purpose is sometimes difficult to procure. The homely process now described is quite inferior to, and more costly than, that pursued in factories, and should only be resorted to when a genuine article cannot otherwise be obtained.

We have referred to super-phosphate of lime prepared from bones. A new source of supply has, however, been discovered of late years, the extent and importance of which is becoming more apparent as investigation proceeds. We allude to those phosphoric deposits found in such abundance in the crag, and upper and lower green-sand formations in the south of England. The existence of these fossil animal remains was first pointed out by Drs. Mantel and Buckland, though it is to Professor Henslow that we are indebted for having called attention to their eminent agricultural value, and described the localiti4s whence they may be most readily obtained. These remains consists of the fractured and rolled bones of sharks, gigantic sea-lizards, and whales, which at one period of our earth’s history much gave existed in myriads in our ocean and seas. Mixed with these bones are found manly fish-teeth and shells of different species, and likewise immense numbers of rolled, water-worn pebbles, which at one period were imagined to be the fossilized excrements of the animals themselves, and were of this account called coprolites by Professor Henslow and others. Although this has since been proved a mistake, the name has been adopted, and will probably be continued, These fossil bones, and so-called coprolites of the crag, are found in enormous quantities on the coast of Suffolk, Norfolk, and Essex, whence Mr. Lawes of Rothamstead obtained nearly the whole of the material which he employed in the preparation of his well-known "coprolite manure" or "Lawes" super-phosphate." Already, it is believed, several thousands of tons of these fossils in one form or other are annually sold for manure, with a rapidly increasing demand. Those found in the crag formation are exceedingly hard, and require to be ground by powerful machinery ,and dissolved in sulphuric acid, to render the phosphate of lime available as manure. Fossils, though less abundant in the green-sand, can be reduced to the requisite fineness by simple machinery, and are then fit for agricultural purposes without any chemical preparation. They are found plentifully in the parish of Farnham, so long celebrated for the excellence and abundance of its hops, which are now discovered to be due to the presence in the soil of these fossil remains. The discovery of these mines of manure in various parts of our country was made most seasonably, and has proved of immense national importance. When Liebig predicted that, "in the remains of an extinct animal world England is to find the means of increasing her wealth in agricultural produce, as she has already found the great support of her manufacturing industry in fossil fuel," he was regarded by many as merely indulging a fine philosophic fancy; but enough has already been realized to convince the most skeptical of the importance of the date on which he founded his opinion. [Footnote 348-1]

On mixing a quantity of bone-dust with its own bulk of mould or sand, and wetting the whole with its liquid which oozes from the dung-heap, violent fermentation immediately ensues, dissolving the bones, and making them more readily available for the nourishment of the turnip crop. Many farmers are so satisfied with this preparation, that they dispense with the acid. This is not judicious, as the super-phosphate of lime is a more valuable manure than bones dissolved by simple fermentation.

Bones are sometimes applied as a top-dressing to grass land with singular success. "this Cheshire practice consists in applying an extraordinary dose of bones to pastureland. ‘For pasture land, especially the poorer kind,’ says Mr. Palin, ‘there is nothing equal to bone manure, either as regards the permanency of its effects, or the production of a sweet luxurious herbage, of which all cattle are fond. Many thousand acres of the poor clay soils have been covered with this manure during the last eight or ten years. The average quantity used is about a ton and a half to the acre; it is therefore a landlords improvement, on which seven or eight per cent, is generally paid. Boiled bones act as long as unboiled bones, retaining the phosphorus, though not so quickly, having lost the animal matter. Boiled bones (1845)cost £3, 10s. per ton; the outlay then was five guineas per acre, sometimes £7 or £8. ’I have known’ says a correspondent, ‘many instances where the annual value of our poorest clay lands has been increased by an outlay of from £7 to £8 an acre, at least 300 per cent; or, in other words, that the land has been much cheaper after this outlay at 30s., than in its native state of 10s. per acre; with the satisfaction of seeing a miserable covering of pick-grass, rushes, hen-gorse, and other noxious weeds, exchanged for a most luxuriant herbage of wild clover, trefoil, and other succulent grasses.’ Though much of the clover and trefoil may disappear in five or ten years (sometimes they last fifteen years), and excellent herbage remains. ‘Draining,’ the writer adds, ‘may be carried too far where bones are used, for boned lands suffer by a dry summer. The land should be kept cool.’ I have found the same thing on water meadows. The freer the grass is growing, the more it suffers from drought; this is natural, for a larger supply of sap is required. This writer adds, ‘I have known many poor, honest, but half-broken man, raised from poverty to comparative independence, and many a sinking family saved from inevitable ruin, by the help of this wonderful manure.’ Indeed, I believe, land after boning will jeep three cows where two fed before. As to this practice, however, caution is necessary. It seems to belong to cold clays for grass in Cheshire, though on such soil it would hardly answer elsewhere, even form turnips. A Cheshire landlord told me that he had tried it vainly for grass in Suffolk. I know no case of its success our of Cheshire, unless in the bordering counties, and have heard some cases of it adopt it hastily. We only know it to have succeeded about Cheshire, which is on the red marks geologically , and on the rainy side of the country, and must remember that it is a costly proceeding, striking in its success, but as yet circumscribed in its practice, and therefore in the proof of its efficacy." [Footnote 349-1]


348-1 Journal of the Royal Agricultural Society of England, vol. ix, p. 56, and vol. xii, p. 91.

349-2 Article by Mr Pusey. See Journal of the Royal Agricultural Society of England, vol. xi, p. 409.

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