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 9¾ tons of dung and 2 cwt. of guano, for all the land had been dunged at this rate, and exceeded 14½ 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 £5 per ton, and the guano at £10 per ton, will be at the rate of 2 cwt of each, £1 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."