Charcoal and Guano.—The benefit of charcoal with guano will be understood from the following extract from "Scientific Agriculture," on the nature of charcoal and its use as a manure.—"Charcoal on account of its power of absorbing gases and destroying offensive odors, is a valuable addition to the soil; its operation as a manure is not so direct as some other manures; that is, it is not so useful on account of any element it furnishes to plants, as by the intermediate office which it performs, of absorbing and retaining in the soil those volatile matters which plants require, and which would otherwise escape and be lost. It is beneficial as a top-dressing, and as an ingredient in composts; it evolves carbonic acid in its decomposition, and is in this way directly useful to plants. Its powerful antiseptic properties render it very useful to young and tender plants, by keeping the soil free of putrifying substances, which would otherwise destroy their spongioles and prevent their growth."
And its capacity to absorb many times its bulk of gaseous matter, will always give it value as an absorbent of escaping ammonia from surface dressings of guano.
The editor of the Farmer also says—"In our climate, we should be opposed to all topical applications of any strongly concentrated manure like guano by itself,—and, indeed we should, under all circumstances, prefer to have it ploughed in, if practicable; but as we presume our correspondent has been prevented by circumstances, from using guano at the time of ploughing for wheat; and of course, must avail himself of the next best plan of deriving benefit from its use, we would advise, him next spring, as soon as the frost is out of the ground, and it is in a state to bear a team; to mix, in the proportion of 100 lbs. of guano, one bushel of fine charcoal, and one peck of plaster per acre, then to sow the mixture over his wheat field, lightly harrow the ground, and finish by rolling; and we have no hesitation in saying, that his wheat crop will be benefitted more than twice the cost of the manure. We say to him farther that he need not fear injuring his wheat plants by the operation of harrowing and rolling; for, on the contrary, it will act as a working, and prove of decided advantage. We feel very certain that the admixture of charcoal and plaster with guano, together with the covering it will receive by the harrowing, will prevent any material loss of the ammoniacal principles of the latter; as independent of the affinity existing between charcoal, plaster, and all nitrogeneous bodies, they will be greatly aided by the vital principle of the plants themselves. We are not, however, left to the lights of theory alone, in this matter, but have the experience of the Honorable Mr. Pearce, of Kent county, of this State, to guide us to a practical result,—he used, some years since, a top-dressing of guano and plaster upon his wheat field, and was rewarded by a large increase of crop."
A correspondent says—"I am satisfied from experience and observation in the use of guano for the last twelve years, that the best method, decidedly, of applying it to our crops in this dry climate, is to plow and spade it into the ground; and autumn is the best season for doing this, as it gives time for the pungent salts contained in the guano to get thoroughly mixed with the soil before spring planting. Do not fear to lose the guano, by plowing it as deep as you please—it will not run away, depend upon it. At the south it loses half its virtue if not plowed in at least three inches deep; six to twelve inches would be still better.
"Spread broadcast on grass land, late in the fall or early in the spring, if not plowed in before sowing buckwheat, rye or wheat, then spread it broadcast after sowing the grain, and harrow well and roll the land. This last operation is quite important."
Value of Guano on account of its Phosphates.—He who wishes to have the best grazing grounds, where he can present the richest and most nutritious herbage to his cattle, will keep his ground well supplied or manured with guano that abounds in phosphates, knowing that it will supply the needed nutriment to the grass, and by the grass to the cattle; and thus his stock will be kept in a high condition and full flesh, either for the farm or the market.
Again; he who raises wheat, corn, or other grains, has an equal inducement to look to it that his manures are abundantly impregnated with these essential elements. Phosphates, so available to the raiser of stock, are equally so to the producer of grain; because the size, richness, and nutritious qualities of the grain depend largely on the presence of these in the soil. A farmer, therefore, has a vital interest in this matter, and should obtain what best suits his purpose. The most intelligent English farmers are so well convinced on this point, that substances containing only ten per cent. of phosphate of lime, are sought after, dissolved in sulphuric acid and water, and sprinkled on the soil. Bone dust also is used, and to a certain extent, is available, because one of the principal constituents of bones, is phosphate of lime. But the article in which the phosphates are the most convenient, because the most minutely distributed, is guano; and this, when judiciously used, must find favor wherever it can be obtained.
That which contains a large proportion of phosphates, in combination with ammonia, nitrogen and alkaline salts, apparently in the exact proportion required by nature, such as analysis and experience proves is the case with Peruvian guano, will be sought after by every farmer who reads the evidence of its value which we have given in these pages.
It is idle to talk of bones to restore the waste of phosphates in the soil that is being constantly carried away in grass and grain, beef, pork, mutton, milk and cheese, much of which passes into the sea from the sewers of cities, to be there retained in that great reservoir for the future use of men. It is from that we are now drawing our present supplies. Happily for mankind in all civilized countries, the discovery of guano has, in a providential manner, met the very wants of the times, in reference to the reinvigoration of certain kinds of soil, since this manure furnishes the elements most needed to supply the waste arising from cultivation, and to develop vegetation.
The impossibility of procuring bones enough to supply the wants of the comparative few now engaged in using guano, may be readily learned by any farmer who uses ten tons of guano per annum, if he will undertake to "pick up bones" enough to furnish him the same amount of phosphates contained in that quantity of guano. Then if all who are now using it, would drop guano and take to bones, it would soon be found to be hard picking. Save all the bones and apply them to the soil, is a standing text with us; upon the same soil use all the guano your can procure and you will not need to pick bones—you will grow bones to pick. It may be very patriotic to talk about expending the money at home, for bones, instead of sending it to Peru, for guano; but that talk is all for Buncombe, there is not a particle of sound reason in it. If all the bones in the United States could be saved and applied to the land again, we should still fall short of a supply, and be obliged to do as England did before the introduction of guano; go about and ransack grave yards of great battlefields, for more bones. With all the guano imported, or that will be imported, and all the bones that will be saved, there will still be room for more phosphates in the millions of acres of hungry soil in America. What would be the effect if a few such farms as Willoughby Newton's, and Col. Carter's, who each use 30 to 40 tons per annum of guano, should come all at once into the bone market for their supplies. In our opinion there would be such a rattling among the dry bones, we should hear no more about substituting them for guano. The fact is an incontrovertible one, that nothing on earth nor under the earth, or in the sea, has ever been discovered, which can be used as a substitute for guano. Its small bulk is alone sufficient to commend it to favor.