The Royal Agricultural Society of England offers a prize of £1,000 and the gold medal of the society, for the discovery of a manure with equal fertilizing properties to the guano, of which an unlimited supply can be furnished in England, at £5 per ton.
"Analogy between Bones and Guano.—There is a striking analogy in composition between bones and guano, which is, for other reasons interesting to the practical man.
The following table exhibits the composition of bones compared with guano, supposing both in the dry state. Bones, as they are applied to to the land contain about 18 per cent. of water. Ichaboe guano from 20 to 25 per cent.
| Bones. | Guano. | |
|---|---|---|
| Organic animal matter, | 33 | 56 |
| Phosphates of lime and magnesia, | 59 | 26 |
| Carbonate of lime, | 4 | 6 |
| Salts of soda, | 4 | 10 |
| Salts of potash, | trace | trace |
| Silicious matter | 0 | 2 |
| —— | —— | |
| 100 | 100" |
And these substances are found in guano already in a pulverulent state, while bones have to be reduced by mechanical or chemical means to the same condition before they are of any use as manure. Do not, we again repeat most emphatically, do not waste a bone; dissolve all you can get in sulphuric acid and mix with guano—save and make all the manure possible, both by the stable, compost heap and green crops, and then you will have money to buy guano, by which you can save the immense labor of hauling to distant fields, and still have the satisfaction of seeing them as fertile as those highly manured near home.
When the farmer raises crops for sale, and removes his grain and grasses from the land, he sells a portion of his soil; and if he does not renew in some way the saline matters taken away in his crops, he invariably impoverishes his farm. This work of exhaustion is now going on to an alarming extent, and the prolific wheat lands are to be searched for farther and farther westward as the operation proceeds.
Every one knows the superiority of wheat grown on newly cultivated lands, and most farmers are aware of the fact that soils become exhausted of something, they know not what, but of something essential to the most favorable production of grain. This something is found in guano, and by it the original fertility of land can be more easily, more certainly and cheaply restored than by any other means as yet discovered.
Professor Mapes in one of his letters of advice says; "As no farm, under ordinary usage, will supply as much manure as may be used upon it with profit, I am glad you intend to use guano, as it is an admirable manure, replete with many requirements of plants. The ammonia of the guano is in the form of a carbonate, and therefore so volatile as to escape from the soil into the atmosphere before plants can use it.
"You will readily perceive, therefore, that the sulphuric and phosphoric acids require amendments, and the ammonia should be changed from a carbonate to a sulphate of ammonia, which is not volatile. All this may be readily done by dissolving bone dust in dilute sulphuric acid, mixing it with the guano, and then with a sufficient amount of charcoal dust to render the mass dry and pulverulent. The more charcoal dust the better, as it absorbs and retains ammonia, and after it is in the soil, will continue to perform similar offices for many years, only yielding up ammonia as required by plants, and receiving new portions from rains, dews, &c."
If used as a top dressing, this change from a carbonate to a sulphate may be necessary; but not so if well mixed with the soil, particularly one in which clay predominates. In such a soil it is not even necessary to adhere to the direction to plow the guano deeply under. If it is but slightly harrowed in, the nature of the clay is such it will prevent the escape of the ammonia. If you require phosphates, more than ammonia, add the superphosphate of lime; but in no case omit the guano.