CHAPTER XXXIX.

VALUE OF FERTILIZERS.

In 1857, Prof. S. W. Johnson, in his Report to the Connecticut Agricultural Society, adopted the following valuation:

Potash 4 cents per lb. Phosphoric acid, insoluble in water 4½ ” ” ” ” ” soluble ” ” 12½ ” ” ” Nitrogen 17 ” ” ”

Analyses of many of the leading commercial fertilizers at that time showed that, when judged by this standard, the price charged was far above their actual value. In some cases, manures selling for $60 per ton, contained nitrogen, phosphoric acid, and potash worth only from $20 to $25 per ton. And one well-known manure, which sold for $28 per ton, was found to be worth only $2.33 per ton. A Bone Fertilizer selling at $50 per ton, was worth less than $14 per ton.

“In 1852,” said the Doctor, “superphosphate of lime was manufactured by the New Jersey Zinc Co., and sold in New York at $50 per ton of 2,000 lbs. At the same time, superphosphate of lime made from Coprolites, was selling in England for $24 per ton of 2,240 lbs. The late Prof. Mapes commenced making “Improved Superphosphate of Lime,” at Newark, N.J., in 1852, and Mr. De Burg, the same year, made a plain superphosphate of lime in Brooklyn, N.Y. The price, in proportion to value, was high, and, in fact, the same may be said of many of our superphosphate manures, until within the last few years.”

Notwithstanding the comparatively high price, and the uncertain quality of these commercial manures, the demand has been steadily on the increase. We have now many honorable and intelligent men engaged in the manufacture and sale of these artificial manures, and owing to more definite knowledge on the part of the manufacturers and of the purchasers, it is not a difficult matter to find manures well worth the money asked for them.

“A correct analysis,” said I, “furnishes the only sure test of value. ‘Testimonials’ from farmers and others are pre-eminently unreliable. With over thirty years’ experience in the use of these fertilizers, I would place far more confidence on a good and reliable analysis than on any actual trial I could make in the field. Testimonials to a patent fertilizer are about as reliable as testimonials to a patent-medicine. In buying a manure, we want to know what it contains, and the condition of the constituents.”

In 1877, Prof. S. W. Johnson gives the following figures, showing “the trade-values, or cost in market, per pound, of the ordinary occurring forms of nitrogen, phosphoric acid, and potash, as recently found in the New York and New England markets: _Cents per pound._ Nitrogen in ammonia and nitrates 24 ” in Peruvian Guano, fine steamed bone, dried and fine ground blood, meat, and fish 20 ” in fine ground bone, horn, and wool-dust 18 ” in coarse bone, horn-shavings, and fish-scrap 15 Phosphoric acid soluble in water 12½ ” ” “reverted,” and in Peruvian Guano 9 ” ” insoluble, in fine bone and fish guano 7 ” ” ” in coarse bone, bone-ash, and bone-black 5 ” ” ” in fine ground rock phosphate 3½ Potash in high-grade sulphate 9 ” in kainit, as sulphate 7½ ” in muriate, or potassium chloride 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: _Value per pound._ Nitrogen (ammonia, 17½ c.) 21¾ c. Soluble phosphoric acid 10 c. Reverted ” ” 8 c. Insoluble ” ” 2 c. Potash, as sulphate and phosphate 7½ c.

“The first cargo of Peruvian guano, sold under this guarantee, contained:

_Value per ton_. Ammonia 6.8 per cent $23.80 Soluble phosphoric acid 3.8 ” ” 7.60 Reverted ” ” 11.5 ” ” 18.40 Insoluble ” ” 3.0 ” ” 1.20 Potash 3.7 ” ” 5.55 ------ Estimated retail price per ton of 2,000 lbs. $56.55 Marked on bags for sale $56.00

The second cargo, sold under this guarantee, contained:

_Value per ton_. Ammonia 11.5 per cent $40.50 Soluble phosphoric acid 5.4 ” ” 10.80 Reverted ” ” 10.0 ” ” 16.00 Insoluble ” ” 1.7 ” ” .68 Potash 2.3 ” ” 3.45 ------ $71.43 Selling price marked on bags $70.00

“It is interesting,” said I, “to compare these analyses of Peruvian guano of to-day, with Peruvian guano brought to England twenty-nine or thirty years ago. I saw at Rothamsted thirty years ago a bag of guano that contained 22 per cent of ammonia. And farmers could then buy guano guaranteed by the dealers (not by the agents of the Peruvian Government), to contain 16 per cent of ammonia, and 10 per cent of phosphoric acid. Price, £9 5s. per ton of 2,240 lbs.--say $40 per ton of 2,000 lbs.

The average composition of thirty-two cargoes of guano imported into England in 1849 was as follows:

Ammonia 17.41 per cent. Phosphoric acid 9.75 ” ” Alkaline salts 8.75 ” ”

At the present valuation, adopted by the Agents of the Peruvian guano in New York, and estimating that 5 per cent of the phosphoric acid was soluble, and 4 per cent reverted, and that there was 2 lbs. of potash in the alkaline salts, this guano would be worth:

Value per ton of 2,000 lbs. Ammonia 17.41 per cent $60.93 Soluble phosphoric acid 5.00 ” ” 10.00 Reverted ” ” 4.00 ” ” 6.40 Insoluble ” ” .75 ” ” .30 Potash 2.00 ” ” 3.00 ------- $80.63 Selling price per ton of 2,000 lbs. $40.00

Ichaboe guano, which was largely imported into England in 1844-5, and used extensively as a manure for turnips, contained, on the average, 7½ per cent of ammonia, and 14 per cent of phosphoric acid. Its value at the present rates we may estimate as follows:

Ammonia, 7½ per cent $26.25 Soluble Phosphoric acid, 4 per cent 8.00 Reverted ” ” 10 ” 16.00 ------ $50.25 Selling price per ton of 2,000 lbs. $21.80

The potash is not given, or this would probably add four or five dollars to its estimated value.

“All of which goes to show,” said the Deacon, “that the Peruvian Government is asking, in proportion to value, from two to two and a half times as much for guano as was charged twenty-five or thirty years ago. That first cargo of guano, sold in New York under the new guarantee, in 1877, for $56 per ton, is worth no more than the Ichaboe guano sold in England in 1845, for less than $22 per ton!

“And furthermore,” continued the Deacon, “from all that I can learn, the guano of the present day is not only far poorer in nitrogen than it was formerly, but the nitrogen is not as soluble, and consequently not so valuable, pound for pound. Much of the guano of the present day bears about the same relation to genuine old-fashioned guano, as leached ashes do to unleached, or as a ton of manure that has been leached in the barn-yard does to a ton that has been kept under cover.”

“True, to a certain extent,” said the Doctor, “but you must recollect that this ‘guaranteed’ guano is now sold by analysis. You pay for what you get and no more.”

“Exactly,” said the Deacon, “but what you get is not so good. A pound of nitrogen in the leached guano is not as available or as valuable as a pound of nitrogen in the unleached guano. And this fact ought to be understood.”

“One thing,” said I, “seems clear. The Peruvian Government is charging a considerably higher price for guano, in proportion to its actual value, than was charged 20 or 25 years ago. It may be, that the guano is still the cheapest manure in the market, but at any rate the price is higher than formerly--while there has been no corresponding advance in the price of produce in the markets of the world.”

POTASH AS A MANURE.

On land where fish, fish-scrap, or guano, has been used freely for some years, and the crops exported from the farm, we may expect a relative deficiency of potash in the soil. In such a case, an application of unleached ashes or potash-salts will be likely to produce a decided benefit.

Clay or loamy land is usually richer in potash than soils of a more sandy or gravelly character. And on poor sandy land, the use of fish or of guano, if the crops are all sold, will be soon likely to prove of little benefit owing to a deficiency of potash in the soil. They may produce good crops for a few years, but the larger the crops produced _and sold_, the more would the soil become deficient in potash.

We have given the particulars of Lawes and Gilbert’s experiments on barley. Mr. Lawes at a late meeting in London, stated that “he had grown 25 crops of barley one after the other with nitrogen, either as ammonia or nitrate of soda, but without potash, and that by the use of potash they had produced practically no better result. This year (1877), for the first time, the potash had failed a little, and they had now produced 10 or 12 bushels more per acre with potash than without, showing that they were coming to the end of the available potash in the soil. This year (1877), they obtained 54 bushels of barley with potash, and 42 bushels without it. Of course, this was to be expected, and they had expected it much sooner. The same with wheat; he expected the end would come in a few years, but they had now gone on between 30 and 40 years. When the end came they would not be sorry, because then they would have the knowledge they were seeking for.”

Dr. Vœlcker, at the same meeting remarked: “Many soils contained from 1½ to 2 per cent of available potash, and a still larger quantity locked up, in the shape of minerals, which only gradually came into play; but the quantity of potash carried off in crops did not exceed 2 cwt. per acre, if so much. Now 0.1 per cent of any constituent, calculated on a depth of six inches, was equivalent to one ton per acre. Therefore, if a soil contained only 0.1 per cent of potash, a ton of potash might be carried off from a depth of 6 inches. But you had not only 0.1 per cent, but something like 1½ per cent and upwards in many soils. It is quite true there were many soils from which you could not continuously take crops without restoring the potash.”

“In all of which,” said the Doctor, “there is nothing new. It does not help us to determine whether potash is or is not deficient in our soil.”

“That,” said I, “can be ascertained only by actual experiment. Put a little hen-manure on a row of corn, and on another row a little hen-manure and ashes, and on another row, ashes alone, and leave one row without anything. On my farm I am satisfied that we need not buy potash-salts for manure. I do not say they would do no good, for they may do good on land not deficient in available potash, just as lime will do good on land containing large quantities of lime. But potash is not what my land needs to make it produce maximum crops. It needs available nitrogen, and possibly soluble phosphoric acid.”

The system of farming adopted in this section, is much more likely to impoverish the soil of nitrogen and phosphoric acid than of potash.

If a soil is deficient in potash, the crop which will first indicate the deficiency, will probably be clover, or beans. Farmers who can grow large crops of red-clover, need not buy potash for manure.

On farms where grain is largely raised and sold, and where the straw, and corn-stalks, and hay, and the hay from clover-seed are retained on the farm, and this strawy manure returned to the land, the soil will become poor from the lack of nitrogen and phosphoric acid long before there would be any need of an artificial supply of potash.

On the other hand, if farmers should use fish, or guano, or superphosphate, or nitrate of soda, and sell all the hay, and straw, and potatoes, and root-crops, they could raise, many of our sandy soils would soon become poor in available potash. But even in this case the clover and beans would show the deficiency sooner than wheat or even potatoes.

“And yet we are told,” said the Deacon, “that potatoes contain no end of potash.”

“And the same is true,” said I, “of root-crops, such as mangel-wurzel, turnips, etc., but the fact has no other significance than this: If you grow potatoes for many years on the same land and manure them with nitrogenous manures, the soil is likely to be speedily impoverished of potash.”

“But suppose,” said the Deacon, “that you grow potatoes on the same land without manure of any kind, would not the soil become equally poor in potash?”

“No,” said I, “because you would, in such a case, get very small crops--small, not from lack of potash, but from lack of nitrogen. If I had land which had grown corn, potatoes, wheat, oats, and hay, for many years without manure, or an occasional dressing of our common barnyard-manure, and wanted it to produce a good crop of potatoes, I should not expect to get it by simply applying potash. The soil might be poor in potash, but it is almost certain to be still poorer in nitrogen and phosphoric acid.”

Land that has been manured with farm-yard or stable-manure for years, no matter how it has been cropped, is not likely to need potash. The manure is richer in potash than in nitrogen and phosphoric acid. And the same may be said of the soil.

If a farmer uses nitrogenous and phosphatic manures on his clayey or loamy land that is usually relatively rich in potash, and will apply his common manure to the sandy parts of the farm, he will rarely need to purchase manures containing potash.