Imágenes de páginas
PDF
EPUB

Tabulated results of analyses inade in the months of August and September, 1867, together with

fow analyscs of other chemists, for comparison,

[merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][ocr errors][merged small][merged small][merged small]

Alkalies, magnosia, sulphates, chloridos, fluorides, water, &c., not estimated.

[merged small][merged small][ocr errors][ocr errors][merged small][merged small][merged small][merged small]

44.70

Phosphate of lime....... 49.87 | :50.07 61. 24 | 25.63 46.00 40.28
Phosphate of iron and alu. 1
mina.........

0.86 0.69
Carbonate of lime and mag.
nesia..............

4.73 10.14 8.60 5.04 4. CO 15.32 Organic matter and water....

30. 162 | 48.00 40.64 Sand and loss......

13. 76

[blocks in formation]

.......

11.36

5.00 27.90

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][ocr errors][ocr errors][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][ocr errors][merged small][merged small][merged small]

HOW TO UTILIZE BONE PHOSPHATES. When separated from all impurities, by washing or otherwise, as far as practicable, phosphates should be broken fine enough to grind between heavy millstones, which should be dressed to do as perfect work as possible. The finer the flour is ground the easier its particles dissolve in any acidulated water. Thorough drying before grinding favors extreme comminution when reducing the rock to powder. How far heat may be profitably carried to aid in the complete disintegration of bones or bone phosphates, experiments will determine. When properly ground the fertilizers may be handed over to farmers and planters for solution in that admirable crucible known as a hot, fermenting dunghear.

It is true that the sulphate of lime obtained by treating ground bones or guano with oil of vitriol is valuable as a manure; but gypsum will supply the same fertilizer at less than half the cost of the vitriol. Economy demands that cultivators of the soil purchase sulphuric acid in the shape of land plaster, not in the form of a separate acid, as applied to bone phosphates. But as some families buy wheat flour after it is baked into bread, so many farmers may prefer to purchase plantfood ready cooked for use.

A late number of the Journal of the Royal Agricultural Society of England contains an elaborate paper “On the solubility of phosphatic materials with reference to the practical efficacy of the various forms in which bones are used in agriculture,” by Dr. Voelcker, chemist to the society. His researches have been thorough, and are reliable. He says: “ Eigh-pressure steam renders bones so brittle that they can be easily ground into fine powder, which is readily assimilable by plants."

This is all that any plants need in a manure. He continues:

“Bone-meal prepared by high-pressure steam contains not much less nitrogen than ordinary bone dust, and as a manure is far more efficacious and valuable than the latter. Placed in a heap with ashes or sand, and occasionally moistened with liquid manure or water, bone enters into putrefaction, and becomes a more soluble and energetic manure than ordinary bone dust. An excellent way of making bone dust soluble, it may also be mentioned, is the Norfolk plan of putting it into alternate layers between fresh farm-yard manure, and letting both ferment together in a conical lieap, covered up with earth, to prevent the loss of any fertilizing matter, and secure it from penetration by heavy rains."

Norfolk fariners have long been distinguished as the best in England, which is equivalent to saying they are the best in Europe, and in the world. Whilo many thousands in Great Britain, on the Continent, and in America, lise expensive sulphuric acid to dissolve bone phosphates, Norfolk farmers accomplish the same result by warm carbonic acid, water, and nitrogenous substances in fermenting manure. At the market price of sulphuric acid in the South, planters Low pay as much for one pound in superplosphates as ten pounds of the South Carolina bone tour ought to cost at the mills where it is ground. The chemistry of plant and animal food and nutrition will never do much for agriculture before the true economy and principles of this science are carried home to the tireside and understanding of the men who own and cultivate the soil. Farmers, who are large consumers of acids, alkalies, and alkaline earths, ought to study all their chemical relations in compost heaps, soils, plants, and animals. Every farmer and planter should be able to inquire understandingly in what way nature dissolves the apparently insoluble carbonate of lime, phosphate of lime, and silicate of potash in soils, to proinote the growth of plants. There is no reason to believe that sulphuric acid is in any way applied to that object. Carbonic acid, and others of vegetable origin, are sufficient for the purpose. Water charged with carbonic acid (the cheapest acid known) dissolves the carbonate of lime freely, acts sensibly on the silicates of lime, potash, and soda, and on bolle phosphate reduced to a fine powder. Strong vinegar can be made from sorghum sirup, and used as a solvent on the farm cheaper than sulphuric acid can be bought and used for agricultural purposes. In a word, the same organic acids formed in decay. ing dung-heaps and in good soils, that render the mineral elements of crops available, as obtained from particles of feldspar, mica, hornblende, and other compound ininerals as they exist in clay and sand, are at the service of the farmer to bring South Carolina bone phosphates into solution. Give us the osseous remains of extinct vertebratel animals as pure, as finely ground, and as cheap as possible, and southern planters and farmer's will do all else that is necelful to reorganize them as parts of living beings.

TIIE SOURCES OF PIIOSPHORUS AND SULPIIUR IN SOILS.

While commercial enterprise explores every sea to find islands and locks covered with the excrements of birds to be imported and used as manure; and while geologists and chemists search earnestly in the beds of post-pliocene rivers, lakes, bays, and estuaries for the bones of land and sea monsters developed in an age when oysters in Georgia built up banks of their shells two hundred feet in thickness, with specimens still found one hundred miles from the Atlantic, that measure from eightech to twenty inches in length, and elephants, mastodons, crocodiles, and sharks attained a growth still more incredible, farmers should have sufficient ambition and professional pride to look into their own soils, subsoils, and rocks for a home supply of phosphorus, sulphur, potash, and other substances, without which no crop can grow. In the Patent Office Report for 1850 may be found an essay of nearly a hundred pages on the “ Study of Soils,” in which all the elements of cultivated plants are traced to their source.

Phosphorus and sulphur in combination with iron, as a phosphoret and sulphuret of this metal, often abound in soils—a condition in which they do no good as plant food. The earthy part of every seed of wheat has from seventy-five to eighty per cent. of phosphoric acid and potash as necessary constituents; and while the soil has a plenty of phos. phoret of iron and insoluble silicate of potash, the lack of available phosphoric acid and potash often reduces the yield more than one-half. Crops of corn and cotton are also diminished under like circumstances, when their elements, although present, are unavailable. All such lands need marl or lime, by which the phosphorets and sulphurets of iron are changed, or rather made to produce gypsum and bone earth. The phosphate of alumina is decomposed also by lime, yielding a bone phosphate. Sulphur in combination with iron is converted into an acid by lime, with which it unites to form the sulphate of lime, which is best known as gypsum or land plaster. The power of lime to produce both phosphoric and sulphuric acids in soils where neither existed before, gives to the marl beds which extend from the Chesapeake Bay to the Rio Grande great agricultural importance. Lime often eliminates potash and magnesia from their insoluble silicates in a similar manner. Clay roasted with lime gave Dr. Voelcker about twice as much potash to rain-water as that roasted without lime. It is impossible to account for the greatly increased growth of walnut, hickory, and poplar forest trees on our own limestone lands, which contain fourfold more potash and magnesia in their cells and tubes than smaller trees have that grow on similar clays nearly destitute of lime, without conceding the power of this alkaline earth to decompose the silicates of potash and mag. nesia as derived from their parent rocks, and thereby supply potash and magnesia as well as lime to these magnificent plants. The fertility and general durability of our best lime soils are well known; yet lime is not potash, nor magnesia, nor chlorine, nor soda, nor sulphuric, nor phosphoric acid-all of which appear in our annual crops of grain, grass, and other staples. Lime eliminates these from insoluble minerals as naturally as it forms the stone-like covering of all shell-fish, and the base of all internal skeletons. Its relations to plant life and animal life may be obscure, but they are obviously most intimate and enduring, commencing with some of the oldest sedimentary rocks, which, in the Alleghany range of mountains, Professor Rogers estimates at 40,000 feet in thickness. During all the unknown and apparently almost unlimited geological ages in which these mountains of sea-born rocks have been slowly growing, and serving as the cemetery of expiring species and genera of animals, as well as of individuals, these beings have used lime to cover all their shells, and to give solidity and strength to every bone in their bodies. An element of fertility used by nature so largely and enduringly, thinking farmers will not long neglect.

CALCAREOUS MARLS AND POTASII GREENSANDS.

No owner of a naturally poor clay or sandy farm on the Atlantic slope of the United States can visit the rich calcareous soils to be found in

many of the western and southern States without wishing to try the efficacy of lime, marl, or greensand for the improvement of bis comparatively sterile land. Governor Hammond has applied some 300,000 bushels of shell marl from Shell Bluff, on the Savannah River, in Georgia, to his plantation at Silver Bluff, on the South Carolina side of the same river, with entire satisfaction. Mr. H. Burgwyn, of Northampton County, North Carolina, (a large and successful farmer,) says that "no gold mine is so valuable as a good marl pit.” The late Thomas Affleck writes:

"Lime is an absolutely indispensable ingredient in the soil in which fruit-trees of any kind are grown, and especially the apple and pear. Until I was convinced of this fact, I found great difficulty in producing a healthy and vigorous growth upon many varieties of the apple. By marling I removed the difficulty; the wood became short, jointed, and healthy, the foliage abundant and persisting until frost, the fruit large, sound, and free from specks and blemishes, such as before disfigured some kinds."

Twenty-two years ago cotton sold in Augusta, Georgia, at five cents a pound, and fresh land in the southern and southwestern parts of the State could be bought at ten cents au acre. The price paid for cotton was too low to do more than return small wages for the labor of raising it on rich land, without restitution. Hence plantinglands, whether rich or poor, sold at mere nominal prices. Now cotton is worth at least fifteen cents per pound in gold, and the raw material for making it more than five times its value in 1847. Whatever concentrated fertilizers may be extracted from marl, and the greensands of New Jersey, and in States south of it, have an excellent home market, which time is more likely to increase than diminish.

The greensands of New Jersey are so extensive, and so rich in potash, that nothing is hazarded in saying that millions of tons of this alkali exist therein, which science and art may yet extract, perhaps very much as common wood-ashes are made to give up their soluble potash for domestic use and commercial and manufacturing purposes. It is more than probable that many unsuccessful attempts were made to extract good commercial pearlash from wood-ashes before any one could claim success; but these repeated failures did not prove that all efforts in that direction must end in failure. Southern agriculture wants a vast amount of potash, which greensand contains in quantities apparently inexhaustible. As farmers and planters we do not need, nor want, the silicious sand, nor the alumina, nor the iron, nor the lime that may be found in the same bed with potash. Throw out these, and we will pay a fair price in cotton, wheat, corn, meat, and tobacco for the precious alkali.

Good marls so abound in the States of Maryland, Virginia, North Carolina, South Carolina, Georgia, Alabama, Florida, Mississippi, Louisiana, Texas, and Arkansas, all of the same geological age and formation, (the pliocene of Lyell,) that their presence or absence on the ground or under its surface is mainly a question of elevation above tide-water. Within five miles of Washington City, and a little north of the Marlboro road, in a gully, may be seen the outcrop of a stratum of oyster and other shells of unknown extent and thickness. These marine shells are estimated to be over one hundred feet above the water in the Potomac. The hills of giant oyster shells that extend from Shell Bluff, on the Savannah River, thirty miles below Augusta, westward several miles, are one hundred and fifty feet above the Atlantic, and over one hundred miles from it. Between this remarkable mass of shells, generally quite free from sand and clay, and the Keys of Florida, a distance of some five hundred

and fifty or six hundred miles, there may be many "tish basins” filled with phosphates. We do not know what organic remains there may be in such large and true basins as that of the Okefenoke swamp, which covers an area of 500,000 acres, and in other swamps in southern Gcorgia and the peninsula of Florida. If dried peat, or any species of aquatic moss, is worth anything for fuel when pressed and dried, the great swamps of Georgia can supply almost any quantity. It is found on analysis that they contain from five to ten per cent. of ash and earthy matter. Hanging moss on cypress and other forest trees has about one per cent. of ash, half of which is lime. One hundred pounds of dry Okerenoke muck will take up without dripping nearly four hundred pounds of the urine of cattle when used as bedding. By drying the water out under a shed, and again saturating the muck with urine from a tank, repeatedly, a very concentrated mass of agricultural salts may be cheaply obtained. On thousands of plantations the leaves of forest trees growing in love grounds will supply salts of lime, potash, and magnesia cheaper than they can be bought in any market. These decaying with marl, gypsum, finely ground phosphates, and a sprinkling of common salt, give a valuable fertilizer ata moderate cost. Direct research shows that twelve times more of the mineral food of plants exists in one hundred pounds of the leaves of the long-leaf pine than in a like weight of the wood of this abundant forest tree. There is not a tree, nor a spring of water, nor a swamp, nor a brook on any farm that will not yield cheap manure. The water-shed of the Mississippi River drains an area of 1,100,000 square miles, from which a vast amount of agricultural salts is annually washed into the Gulf of Mexico. Judicious irrigation will save much of these salts for manure.

SALT FROM SEA-WATER AS A FERTILIZER.

In many places sea-water is so easily evaporated by the sun, as at the Keys of Florida, and along our southern coast, at Turk's Island, and elsewhere, that salts of soda, lime, magnesia, and perhaps potash, may be had for manure at a low price from this source. What but a lack of enterprise, or a want of knowledge on the subject, prevents the ocean from giving back to our washed and impoverished fields even more fertilizing salts, because more concentrated, than heavy rains, much plow. ing up and down hills, and other follies, ever washed into the sea ? The sulphates of lime and magnesia, and the chlorides of calciun and other bases, which are much in the way in the manufacture of pure salt, will add materially to its value as a manure. If good Turk's Island salt can be made at from six to eight cents per bushel, as is stated, salt for fertilizing the soil, or for the “dung heap," can be produced at five cents per bushel. A demand for salts of this character will soon lead to an adequate supply, for the ocean is inexhaustible. It teems with animals and vegetables, and its waters abound in their food. The same elements that make the bones, fleshi, blood, and milk of whales will do as much for our cattle and ourselves. The lime that protects bivalves from injury, and the sulphates, phosphates, and chlorides organized in marino animals and plants, are just as useful to our farms before as after this service in salt water. This water is really very rich in soluble manure. Why not evaporate the water and apply the manure to all our needy fields? Salt for the land and the dung leap is what farmers need; that is, salts of lime, such as form shells and fish-bones, the sulphur, phosphorus, and nitrogen in the flesh and nerves of these animals, and other elements of concentrated fish guano.

« AnteriorContinuar »