Part 12

2. Was to have twelve tons per acre of farm-yard dung.

3. Was to have six tons of dung, and one cwt. each of guano and dissolved coprolites; and

4. Was to have two cwt. of guano and two cwt. of the coprolites.

Other substances might be tried as additions, but these were to be the standard experiments.

Mr. Cholmeley's turnips, grown on a loamy soil had the heaviest crop on No. 3, the dung, coprolite, and guano, beating the farm-yard manure by some 5-3/4 tons per acre.

Mr. Johnson's experiments were tried with various manures singly; and his Peruvian guano gave the greatest weight of the class of substances tried; but 10 cubic yards of farm-yard manure had previously been applied to the whole land.

Mr. Maulevere's heaviest weight, also applied singly, was with the 12 tons of dung; but only 14 cwt. more than the dressing with 2 cwt. of coprolites. This soil was a light clay.

Mr. Newham's on a limestone soil, were the heaviest with No. 3--the same as Mr. Cholmeley's--and were 16 cwt. heavier than an application of dung alone.

Mr. Outhwaite's, on a hungry gravel, were the heaviest, with 9-3/4 tons of dung and 2 cwt. of guano, for all the land had been dunged at this rate, and exceeded 14-1/2 tons of dung by 2 tons 9 cwt. per acre.

Mr. Scott's were the heaviest on No. 4,--the guano and coprolites, and 1 ton 7 cwt. more than 20 tons of dung,--his soil was a strong loam.

Mr. Wailes's were the heaviest, with 4 cwt. of coprolites, showing an increase over 20 tons of dung of 2 tons 9 cwt. per acre; the soil is a useful loam.

The first fact which strikes the observer, is, that as a general rule, there is not only an addition to the crop by the addition of those artificial manures, but there is, in some cases, more absolute crop produced by them than by farm-yard manure alone.

Now to bring this to the test of figures, the coprolites at L5 per ton, and the guano at L10 per ton, will be at the rate of 2 cwt of each, L1 10s per acre. Now assuming this to be equal to 20 tons of dung per acre, we should require to be able to produce the dung at 1s 6d per ton to cost us the same money. But it can be neither produced nor purchased at any such money. In the whole of the cases referred to, the manure is most costly, and yet we find hardly any case where there is not an addition to the crop, of say two to three tons of turnips per acre, by such an increase of manure as the guano. Now, if a ton of turnips be worth 10s., or even 9s, there is at once an element of repayment; for, if a soil be in a condition to give a large crop of turnips, it is almost certain to be capable of giving a large crop of any other plant to succeed.

Mr. Charnock gives it as the result of his practical experience, that 4 cwt. of Peruvian guano, without manure, is the cheapest and best mode of growing turnips; but the general testimony seems to be decidedly in favor of what all farmers find it the best and easiest to do, viz., to add a small quantity of artificial manure to that which the farm will supply, and so to spread the whole over the land, rather than put all the dung in one place, and all the artificial manure in another.

No one can doubt the true statement of this report, which proves $7 50. worth of guano equal to 20 tons of manure--reducing the worth of that to one shilling and sixpence--about 34 cents--per ton, or one dollar a cord. Now, as manure is often estimated in this country by the cord, and valued at about $4, and applied at the rate of 6 cords per acre, it follows that a saving of $14 50 per acre may be made by using 250 lbs. of guano instead of purchasing the manure. This Yorkshire experiment exactly corresponds with those made in this country, some of which we have detailed, and which proves that a farmer cannot buy manure at the common selling prices; and if he hauls his own the distance of a mile, he will expend more value of time, than it is worth to him on the land; because the same value of time--"time is money"--expended for guano, will bring him better returns. In this, as before stated, we are confirmed by Professor Mapes; and here is the opinion of Mr. Hovey of Boston, the eminent horticulturist, which we find in the August No. of his magazine, as follows--

"If, after such evidence as this, farmers will continue to buy ashes at eight cents a bushel, or manure at three to six dollars a cord, including carting, and use them alone, then let them do so, but they should not complain that their crop cost more than it comes to. To orchardists and fruit growers, this information is of the greatest value, and we trust they will not let it pass unheeded."

This opinion is valuable because it has been stoutly asserted, that however well guano might answer at the South, it was of no use in the hard soil and cold climate of New England. This is a fallacy which will soon be cured by knowledge, and self-interest is a very strong prompter towards the acquisition of the knowledge, that guano is the best, cheapest, most suitable, convenient and productive manure ever used by a New England farmer, and just as suitable for that climate and soil as it is for Virginia. We assert, without fear of successful contradiction, that there is not a farm--not a field--covered with five-finger vines and mullens, in the State of Massachusetts, which may not be made to produce as profitable crops, by the use of guano, as any Connecticut river farm. Farmers are about the hardest class of men in the world to learn new doctrines; or that science has anything to do with the business of this life, and what all other life in a civilized country is dependent upon. Yet science teaches, by unerring truths, that the plants the farmer cultivates, are composed of carbon, obtained by plants chiefly from the soil and atmosphere; oxygen and hydrogen, obtained by plants chiefly from water, carbonic acid, &c.; nitrogen obtained by plants chiefly from manure, and also from rain and snow; silicium, in combination with oxygen, called silicia or sand; lime in combination with phosphoric and other acids; potash and soda in combination with acids; magnesia, in combination with acids, and various oxides of metals, the presence of which, however, is not very important, as they exist in an exceedingly small quantity. And that guano is composed of ammonia (formed of nitrogen and hydrogen,) combined with carbonic, oxalic, phosphoric, and other acids; lime, combined with phosphoric oxalic, and other acids; potash and soda, combined with muriatic and sulphuric acids; magnesia, combined with phosphoric and other acids; animal organic matter, containing carbon, and also nitrogen.

Now, is it not enough to prove that all the ingredients, with the exception of the metallic oxides, exist in guano, which are required by the plants grown for the sustenance of man.

Putting guano into the soil, therefore, as a manure, is clearly restoring to the earth those substances which plants abstract from it, and which are absolutely necessary for their growth.

The questions, then, which the farmer should now ask are, "which is best for me to buy, guano or coarse manure?" The evidence just given answers that question. "I have manure, teams, and men to haul it; my fields are from one to three miles distant, is it economy for me to let my teams lay idle and buy guano?" By no means. But you can probably employ men and teams in other improvements to much better advantage. With your manure make all your home lots exceedingly rich. With your men and teams clear off stones, dig ditches to put them into, drain your land, or build fence--bring bog meadows and swamps into dry cultivation--send every little brook through artificial channels for irrigation--send water up from lowland springs and streams by hydraulic rams for the same purpose, and for stock on the hills; or bring it down from hillsides if you are so situated; and buy guano for those distant fields, instead of wasting time in the laborious operation of hauling manure. Those who use guano, are enabled by the saving of time, to say nothing of their increased profits, to make improvements which are utterly impossible to accomplish under the old system.

How to choose Guano.--As we are satisfied no sensible reader can have perused the preceding pages, without having come to the determination to make a trial for himself, we will give him some general instructions about buying guano.

In the first place, we lay it down as an incontrovertible axiom, that the Peruvian guano, at the current price for years of that and all other, is the cheapest and best, because it contains the largest amount of ammonia, in a perfectly dry state; as a carbonate, true, but because dry, it is permanent and not likely to loose by volatilization by long keeping.

If other varieties contain a larger proportion of phosphates, and are sold at a less price, experience proves they are not cheaper. If an additional quantity of phosphates is desirable, it can be obtained in a cheaper form from dissolved bones, or bone dust and shavings of bone workers; or from mineral phosphates of lime. Recollect, guano under no other name, has ever equalled the Peruvian, in the results as compared with the quality or cost.

Therefore buy none but Peruvian. To guard against deception, be careful of whom you buy. If you cannot buy directly from the agents, be sure the character of your merchant is a sufficient guarantee against adulteration.

To test the quality of Guano.--The best test is the price. Unlike other merchandise, this article is not subject to fluctuations. Being a government monopoly, the price at which the agents are to sell here is fixed in Peru, and that price may be easily known; therefore, if any dealer offers you Peruvian guano at "a reduced price," you may be sure the quality is reduced also. Remember, that the lowest price by the ship load, it can be procured for of the agents in Baltimore or New York is $46 per ton of 2240 lbs. To this, every fair, honest dealer, must add freight, insurance and profit. Every man who sells without such addition, you may be sure will make his profit by short weight or adulteration.

The next best test is its appearance. Good Peruvian guano is an impalpable powder, perfectly dry to the touch, of a uniform brownish yellow color, with a strong smell, like that of spirits of hartshorn, contained in ammoniacal smelling bottles. But the smell is no test; that which smells strongest may be worst, as the ammonia may be disengaged by moisture or by the addition of lime or salt.

The adulteration of guano is carried to a great extent in England, and probably will be in this country. The principal adulterations are made by the addition of loam, marl, sand, plaster, old lime, ashes, chalk, salt, moisture, and by mixture with other guano of a cheaper quality. The farmer need not depend upon the assertion, "this is a genuine article--here is the inspector's certificate." We would not give a straw for a corn basket full of certificates of analysis. The buyer must analyse for himself. Mr. Nesbit, analytical chemist, London, has just published a pamphlet from which we have condensed some very plain, short, simple rules for testing the quality of guano. As the adulterating substances are generally heavier than the guano, they may be detected by a comparison of weight and measure. To do this, get a small glass tube closed at one end, and weigh accurately an ounce of pure guano, put it in the tube and carefully mark the hight it fills--try several samples--if there is any difference, mark it. Now weigh an ounce from a sample adulterated with one fourth its bulk of any or all the preceding list of articles used for that purpose, and you will find the difference of bulk between that and the genuine, very perceptible.

Test by Burning.--Guano burnt to ashes at a red heat will leave an ash of a pearly white appearance, not varying in weight from 30 to 35 per cent. of the quantity burnt. If it is adulterated with marl, sand, clay, &c., the ash will be about 60 or 65 per cent, of the weight tested, and be colored with the iron always present in the adulterating substances, and which is never found in pure guano. This test, to be accurate, must be done with a nice pair of scales and a platinum cup, which may be heated over a spirit lamp. Ten grains of the guano are placed in the platinum cup, which is held by the tongs in the flame of the spirit lamp for several minutes, until the greater part of the organic matter is burnt away. It is allowed to cool for a short time, and a few drops of a strong solution of nitrate of ammonia added, to assist in consuming the carbon in the residue. The cup is again heated, (taking care to prevent its boiling over, or losing any of the ash,) until the moisture is quite evaporated. A full red heat must then be given it, when, if the guano be pure, the ash will be pearly white, and will not exceed 3-1/2 grains in weight. If adulterated with sand, marl, &c., the ash will always be colored, and will weigh more than 3-1/2 grains. Even the simple burning of a few grains of guano, on a red hot shovel, will often indicate by the color whether a fraud has been committed; but we cannot particularly recommend this method, as the iron of the shovel itself will sometimes give a tinge to the ash. This might be obviated by burning the sample on a common earthen plate.