| Cents per pound. | |
Nitrogen in ammonia and nitrates | 24 |
Nitrogen in Peruvian Guano, fine steamed bone, dried and fineground blood, meat, and fish | 20 |
Nitrogen in fine ground bone, horn, and wool-dust | 18 |
Nitrogen in coarse bone, horn-shavings, and fish-scrap | 15 |
Phosphoric acid soluble in water | 12½ |
Phosphoric acid “reverted,” andin Peruvian Guano | 9 |
Phosphoric acid insoluble, infine bone and fish guano | 7 |
Phosphoric acid insoluble, incoarse bone, bone-ash, and bone-black | 5 |
Phosphoric acid insoluble, infine ground rock phosphate | 3½ |
Potash in high-grade sulphate | 9 |
Potash in kainit, assulphate | 7½ |
Potash in muriate, or potassiumchloride | 6 |
“These ‘estimated values,’” says Prof. Johnson, “are not fixed, but vary with the state of the market, and are from time to time subject to revision. They are not exact to the cent or its fractions, because the same article sells cheaper at commercial or manufacturing centers than in country towns, cheaper in large lots than in small, cheaper for cash than on time. These values are high enough to do no injustice to the dealer, and accurate enough to serve the object of the consumer.
“By multiplying the per cent of Nitrogen, etc., by the trade-value per pound, and then by 20, we get the value per ton of the several ingredients, and adding the latter together, we obtain the total estimated value per ton.
“The uses of the ‘Valuation’ are, 1st, to show whether a given lot or brand of fertilizer is worth as a commodity of trade what it costs. If the selling price is no higher than the estimated value, the purchaser may he quite sure that the price is reasonable. If the selling price is but $2 to $3 per ton more than the estimated value, it may still be a fair price, but if the cost per ton is $5 or more over the estimated value, it would be well to look further. 2d, Comparisons of the estimated values, and selling prices of a number of fertilizers will generally indicate fairly which is the best for the money. But the ‘estimated value’ is not to be too literally construed, for analysis cannot always decide accurately what is the form of nitrogen, etc., while the mechanical condition of a fertilizer is an item whose influence cannot always be rightly expressed or appreciated.
“The Agricultural value of a fertilizer is measured by the benefit received from its use, and depends upon its fertilizing effect, or crop-producing power. As a broad general rule it is true that Peruvian guano, superphosphates, fish-scraps, dried blood, potash salts, plaster, etc., have a high agricultural value which is related to their trade-value, and to a degree determines the latter value. But the rule has many exceptions, and in particular instances the trade-value cannot always be expected to fix or even to indicate the agricultural value. Fertilizing effect depends largely upon soil, crop, and weather, and as these vary from place to place, and from year to year, it cannot be foretold or estimated except by the results of past experience, and then only in a general and probable manner.”
“It will be seen,” said the Doctor, “that Prof. Johnson places a higher value on potash now than he did 20 years ago. He retains the same figures for soluble phosphoric acid, and makes a very just and proper discrimination between the different values of different forms of nitrogen and phosphoric acid.”
“The prices,” said I, “are full as high as farmers can afford to pay. But there is not much probability that we shall see them permanently reduced. The tendency is in the other direction. In a public address Mr. J. B. Lawes has recently remarked: ‘A future generation of British farmers will doubtless hear with some surprise that, at the close of the manure season of 1876, there were 40,000 tons of nitrate of soda in our docks, which could not find purchasers, although the price did not exceed £12 or £13 per ton.’”
“He evidently thinks,” said the Doctor, “that available nitrogen is cheaper now than it will be in years to come.”
“Nitrate of soda,” said I, “at the prices named, is only 2½ to 2¾ cents per lb., and the nitrogen it contains would cost less than 18 cents per lb., instead of 24 cents, as given by Prof. Johnson.”
“No. 1 Peruvian Guano, ‘guaranteed,’ is now sold,” said the Doctor, “at a price per ton, to be determined by its composition, at the following rates: