The necessity of restoring inorganic substances to the soil, may be better understood by examining the following table:
Mr. Prixdeaux states that the following quantities (of inorganic matters) are removed from an acre of soil by a crop of wheat, of 25 bushels of grain, and 3000 lbs. of straw--
_By the grain._ _By the straw._ _Total._ lbs. lbs. lbs. Potash, 7.15 22.44 29.59 Soda, 2.73 0.29 3.02 Magnesia, 3.63 6.99 10.62 Phosphoric acid, 15.02 5.54 20.56 Sulphuric acid, 0.07 10.49 10.56 Chlorine 0.00 1.98 1.98 ---- ---- ---- 28.60 47.73
Gross weight to be returned to an acre, 76.33
Professor Johnson says--"Soils are barren either from the presence of a noxious principle or the absence of a necessary element. It is therefore highly important to be able to distinguish between the two cases.
"The art of culture is almost entirely a chemical art. Its processes are explained on chemical principals in part, but partly on mechanical and natural ones.
"All forms of matter may be divided into one of the two great groups--organic or inorganic matter."
In Peruvian guano, both these substances exist in a better and cheaper form than can be obtained from any other source.
The editor of the Genesee farmer, whose scientific information none can dispute, strongly corroborates this opinion. In a late number he says--If we admit that phosphate of lime is a necessary ingredient in a special manure for wheat--Peruvian guano would at present be much the cheapest source of it; for, in addition to the 16 per cent. of ammonia, it contains 20 per cent. of phosphate of lime in first-rate condition for assimilation by the plant, as well as other fertilizing ingredients of minor importance.
As a manure for wheat, therefore, we greatly prefer good Peruvian guano, even to the _improved_ superphosphate of lime.
_Difference in favor of Guano over Bone dust._--Robert Monteith, England, dressed oat ground with 276 lbs. guano per acre, cost 31 shillings, produce 59 bushels, value £7 7s 6d. Same quality of land with 10 bushels bone dust, cost 23 shillings and fourpence, produced 43 bushels value £5 7s 6d, which gives a balance in favor of guano of £1 12s 4d, or about $7 50 per acre.
_Difference in favor of Guano over Manure._--The Yorkshire Agricultural Society of England, instituted a series of experiments several years ago for the purpose of working out practical facts in relation to guano, through a series of crops, upon different soils, by different persons, upon whose report the utmost reliance might be placed, so as to determine the value, or advantage to British farmers, who might use this extraordinary fertilizer. This report has just been published, and the following is a synopsis of the results. The experiments were arranged under the following heads--