"It is perhaps not necessary," said I, "to give any direction for treating bones with sulphuric acid. We have got beyond that. We can now buy superphosphate cheaper than we can make it from bones."

"But is it as good?" asked the Deacon.

"Soluble phosphate of lime," said I, "is soluble phosphate of lime, and it makes no difference whether it is made from burnt bones, or from phosphatic guano, or mineral phosphate. That question has been fully decided by the most satisfactory experiments."

"Before you and the Deacon discuss that subject," said the Doctor, "it would be well to tell Charley what superphosphate is."

"I wish you would tell me," said Charley.

"Well," said the Doctor, "phosphate of lime, as it exists in bones, is composed of three atoms of lime and one atom of phosphoric acid. Chemists call it the tricalcic phosphate. It is also called the basic phosphate of lime, and not unfrequently the 'bone-earth phosphate.' It is the ordinary or common form of phosphate of lime, as it exists in animals, and plants, and in the various forms of mineral phosphates.

"Then there is another phosphate of lime, called the dicalcic phosphate, or neutral phosphate of lime, or reverted phosphate of lime. It is composed of one atom of water, two atoms of lime, and one atom of phosphoric acid.

"Then we have what we call superphosphate, or acid phosphate of lime, or more properly monocalcic phosphate. It is composed of two atoms of water, one atom of lime, and one atom of phosphoric acid. This acid phosphate of lime is soluble in water.

"The manufacture of superphosphate of lime is based on these facts. The one-lime phosphate is soluble, the three-lime phosphate is insoluble. To convert the latter into the former, all we have to do is to take away two atoms of lime.

"Sulphuric acid has a stronger affinity for lime than phosphoric acid. And when you mix enough sulphuric acid with finely ground three-lime phosphate, to take away two atoms of lime, you get the phosphoric acid united with one atom of lime and two atoms of water."

"And what," asked the Deacon, "becomes of the two atoms of lime?"

"They unite with the sulphuric acid," said the Doctor, "and form plaster, gypsum, or sulphate of lime."

"The molecular weight of water," continued the Doctor, "is 18; of lime, 56; of sulphuric acid, 80; of phosphoric acid, 142.

"An average sample of commercial bone dust," continued the Doctor, "contains about 50 per cent of phosphate of lime. If we take 620 lbs. of finely-ground bone-dust, containing 310 lbs. of three-lime phosphate, and mix with it 160 lbs. of sulphuric acid (say 240 lbs. common oil of vitriol, sp. gr. 1.7), the sulphuric acid will unite with 112 lbs. of lime, and leave the 142 lbs. of phosphoric acid united with the remaining 56 lbs. of lime."

"And that will give you," said the Deacon, "780 lbs. of 'dissolved bones,' or superphosphate of lime."

"It will give you more than that," said the Doctor, "because, as I said before, the two atoms of lime (112 lbs.) are replaced by two atoms (36 lbs.) of water. And, furthermore, the two atoms of sulphate of lime produced, contained two atoms (36 lbs.) of water. The mixture, therefore, contains, even when perfectly dry, 72 lbs. of water."

"Where does this water come from?" asked the Deacon.

"When I was at Rothamsted," said I, "the superphosphate which Mr. Lawes used in his experiments was made on the farm from animal charcoal, or burnt bones, ground as fine as possible—the finer the better. We took 40 lbs. of the meal, and mixed it with 20 lbs. of water, and then poured on 30 lbs. of common sulphuric acid (sp.g. 1.7), and stirred it up rapidly and thoroughly, and then threw it out of the vessel into a heap, on the earth-floor in the barn. Then mixed another portion, and so on, until we had the desired quantity, say two or three tons. The last year I was at Rothamsted, we mixed 40 lbs. bone-meal, 30 lbs. water, and 30 lbs. acid; and we thought the additional water enabled us to mix the acid and meal together easier and better."

"Dr. Habirshaw tells me," said the Doctor, "that in making the 'Rectified Peruvian Guano' no water is necessary, and none is used. The water in the guano and in the acid is sufficient to furnish the two atoms of water for the phosphate, and the two atoms for the sulphate of lime."

"Such is undoubtedly the case," said I, "and when large quantities of superphosphate are made, and the mixing is done by machinery, it is not necessary to use water. The advantage of using water is in the greater ease of mixing."

"Bone-dust," said the Doctor, "contains about 6 per cent of water, and the sulphuric acid (sp.g. 1.7) contains about one-third its weight of water. So that, if you take 620 lbs. of bone-dust, and mix with it 240 lbs. of common sulphuric acid, you have in the mixture 117 lbs. of water, which is 45 lbs. more than is needed to furnish the water of combination."

"The superphosphate produced from 620 lbs. of bones, therefore," continued the Doctor, "would contain:

Phosphoric acid} {142 lbs. Lime } acid phosphate { 56 " Water } { 36 "

Sulphuric acid } {160 lbs. Lime } sulphate of lime {112 " Water } { 36 "

Organic matter, ash, etc., of the bones [A] 335 " ———— Total dry superphosphate 877 " Moisture, or loss 45 " ———— Total mixture 922 lbs.

[A] Containing nitrogen, 23-1/2 lbs.

"There is a small quantity of carbonate of lime in the bones," said I, "which would take up a little of the acid, and you will have a remarkably good article if you calculate that the 620 lbs. of bone-dust furnish you half a ton (1,000 lbs.) of superphosphate. It will be a better article than it is practically possible to make."

"Assuming that it made half a ton," said the Doctor, "it would contain 14-1/4 per cent of soluble phosphoric acid, and 2-1/3 per cent of nitrogen."

"With nitrogen at 20 cents per lb., and soluble phosphoric acid at 12-1/2 c. per lb., this half ton of superphosphate, made from 620 lbs. of good bone-dust, would be worth $22.50, or $45 per ton."

"Or, to look at it in another light," continued the Doctor, "a ton of bone-dust, made into such a superphosphate as we are talking about, would be worth $72.58."

"How much," asked the Deacon, "would a ton of the bone-dust be considered worth before it was converted into superphosphate?"

"A ton of bone-dust," replied the Doctor, "contains 76 lbs. of nitrogen, worth, at 18 cents per lb., $13.68, and 464 lbs. phosphoric acid, worth 7 cents per lb., $32.48. In other words, a ton of bone-dust, at the usual estimate, is worth $46.16."

"And," said the Deacon, "after it is converted into superphosphate, the same ton of bones is worth $72.58. It thus appears that you pay $26.42 per ton for simply making the phosphoric acid in a ton of bones soluble. Isn't it paying a little too much for the whistle?"

"Possibly such is the case," said I, "and in point of fact, I think bone-dust, especially from steamed or boiled bones, can be used with more economy in its natural state than in the form of superphosphate."

Superphosphate can be made more economically from mineral phosphates than from bones—the nitrogen, if desired, being supplied from fish-scrap or from some other cheap source of nitrogen.

But for my own use I would prefer to buy a good article of superphosphate of lime, containing no nitrogen, provided it can be obtained cheap enough. I would buy the ammoniacal, or nitrogenous manure separately, and do my own mixing—unless the mixture could be bought at a less cost than the same weight of soluble phosphoric acid, and available nitrogen could be obtained separately.

A pure superphosphate—and by pure I mean a superphosphate containing no nitrogen—can be drilled in with the seed without injury, but I should be a little afraid of drilling in some of the ammoniacal or nitrogenous superphosphates with small seeds.

And then, again, the "nitrogen" in a superphosphate mixture may be in the form of nitric acid, or sulphate of ammonia, in one case, or, in another case, in the form of hair, woollen rags, hide, or leather. It is far more valuable as nitric acid or ammonia, because it will act quicker, and if I wanted hair, woollen rags, horn-shavings, etc., I would prefer to have them separate from the superphosphate.



CHAPTER XXXVIII.

SPECIAL MANURES.

Twenty five to thirty years ago, much was said in regard to special manures. Fertilizers were prepared for the different crops with special reference to the composition of the plants.

"But it was known then, as now," said the Doctor, "that all our agricultural plants were composed of the same elements."

"True, but what was claimed was this: Some crops contain, for instance, more phosphoric acid than other crops, and for these a manure rich in phosphoric acid was provided. Others contained a large proportion of potash, and these were called 'potash crops,' and the manure prescribed for them was rich in potash. And so with the other ingredients of plants."

"I recollect it well," said the Doctor, "and, in truth, for several years I had much faith in the idea. It was advocated with consummate ability by the lamented Liebig, and in fact a patent was taken out by the Musgraves, of Liverpool, for the manufacture of Liebig's Special Manures, based on this theory. But the manures, though extensively used by the leading farmers of England, and endorsed by the highest authorities, did not in the end stand the test of actual farm practice, and their manufacture was abandoned. And I do not know of any experienced agricultural chemist who now advocates this doctrine of special manures.

"Dr. Voelcker says: 'The ash-analyses of plants do not afford a sufficiently trustworthy guide to the practical farmer in selecting the kind of manure which is best applied to each crop.'"

"Never mind the authorities," said the Deacon; "what we want are facts."

"Well," replied the Doctor, "take the wheat and turnip crop as an illustration.

"We will suppose that there is twice the weight of wheat-straw as of grain; and that to 10 tons of bulbs there is 3 tons of turnip-tops. Now, 100 lbs. each of the ash of these two crops contain:

Wheat crop. Turnip crop. Phosphoric acid 11.44 7.33 Potash 15.44 32.75 Sulphuric acid 2.44 11.25 Lime 5.09 19.28 Magnesia 3.33 1.56

"There are other ingredients," continued the Doctor, "but these are the most important.

"Now, if you were going to compound a manure for wheat, say 100 lbs., consisting of potash and phosphoric acid, what would be the proportions?"

The Deacon figured for a few moments, and then produced the following table:

100 Lbs. Special Manure for Wheat and Turnips.

Wheat manure. Turnip manure. Phosphoric acid 42-1/2 lbs. 18-1/3 lbs. Potash 57-1/2 " 81-2/3 " —————— —————— 100 lbs. 100 lbs.

"Exactly," said the Doctor, "and yet the experiments of Lawes and Gilbert clearly prove that a soil needs to be richer in available phosphoric acid, to produce even a fair crop of turnips, than to produce a large crop of wheat. And the experience of farmers everywhere tends in the same direction. England is the greatest turnip-growing country in the world, and you will find that where one farmer applies potash to turnips, or superphosphate to wheat, a hundred farmers use superphosphate as a special manure for the turnip crop."

"And we are certainly warranted in saying," continued the Doctor, "that the composition of a plant affords, in practical agriculture, and on ordinary cultivated soils, no sort of indication as to the composition of the manure it is best to apply to the crop."

"Again," continued the Doctor, "if the theory was a correct one, it would follow that those crops which contained the most nitrogen, would require the most nitrogen in the manure. Beans, peas, and clover would require a soil or a manure richer in available nitrogen than wheat, barley, or oats. We know that the very reverse is true—know it from actual, and repeated, and long-continued experiments like those of Lawes and Gilbert, and from the common experience of farmers everywhere."

"You need not get excited," said the Deacon, "the theory is a very plausible one, and while I cannot dispute your facts, I must confess I cannot see why it is not reasonable to suppose that a plant which contains a large amount of nitrogen should not want a manure specially rich in nitrogen; or why turnips which contain so much potash should not want a soil or manure specially rich in potash."

"Do you recollect," said I, "that crop of turnips I raised on a poor blowing-sand?"

"Yes," said the Deacon, "it was the best crop of turnips I ever saw grow."

"That crop of turnips," said I, "was due to a dressing of superphosphate of lime, with little or no potash in it."

"I know all that," said the Deacon. "I admit the fact that superphosphate is a good manure for turnips. What I want to know is the reason why superphosphate is better for turnips than for wheat?"

"Many reasons might be given," said the Doctor; "Prof. Voelcker attributes it to the limited feeding range of the roots of turnips, as compared to wheat. 'The roots of wheat,' says Prof. Voelcker, 'as is well known, penetrate the soil to a much greater depth than the more delicate feeding fibres of the roots of turnips. Wheat, remaining on the ground two or three months longer than turnips, can avail itself for a longer period of the resources of the soil; therefore in most cases the phosphoric acid disseminated through the soil is amply sufficient to meet the requirements of the wheat crop; whilst turnips, depending on a thinner depth of soil during their shorter period of growth, cannot assimilate sufficient phosphoric acid, to come to perfection.' This is, I believe, the main reason why the direct supply of readily available phosphates is so beneficial to root-crops, and not to wheat."

"This reason," said I, "has never been entirely satisfactory to me. If the roots of the turnip have such a limited range, how are they able to get such a large amount of potash?

"It is probable that the turnip, containing such a large relative amount of potash and so little phosphoric acid, has roots capable of absorbing potash from a very weak solution, but not so in regard to phosphoric acid."

"There is another way of looking at this matter," said the Doctor. "You must recollect that, if turnips and wheat were growing in the same field, both plants get their food from the same solution. And instead of supposing that the wheat-plant has the power of taking up more phosphoric acid than the turnip-plant, we may suppose that the turnip has the power of rejecting or excluding a portion of phosphoric acid. It takes up no more potash than the wheat-plant, but it takes less phosphoric acid."

But it is not necessary to speculate on this matter. For the present we may accept the fact, that the proportion of potash, phosphoric acid, and nitrogen in the crop is no indication of the proper proportion in which these ingredients should be applied to the soil for these crops in manure.

It may well be that we should use special manures for special crops; but we must ascertain what these manures should be, not from analyses of the crops to be grown, but from experiment and experience.

So far as present facts throw light on this subject, we should conclude that those crops which contain the least nitrogen are the most likely to be benefited by its artificial application; and the crops containing the most phosphoric acid, are the crops to which, in ordinary practical agriculture, it will be unprofitable to apply superphosphate of lime.

"That," said the Doctor, "may be stating the case a little too strong."

"Perhaps so," said I, "but you must recollect I am now speaking of practical agriculture. If I wanted to raise a good crop of cabbage, I should not think of consulting a chemical analysis of the cabbage. If I set out cabbage on an acre of land, which, without manure, would produce 16 tons of cabbage, does any one mean to tell me that if I put the amount of nitrogen, phosphoric acid and potash which 10 tons of cabbage contain, on an adjoining acre, that it would produce an extra growth of 10 tons of cabbage. I can not believe it. The facts are all the other way. Plant growth is not such a simple matter as the advocates of this theory, if there be any at this late day, would have us believe."



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 4-1/2 " " " " " soluble " " 12-1/2 " " " 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 12-1/2 " " "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 3-1/2 Potash in high-grade sulphate 9 " in kainit, as sulphate 7-1/2 " 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 [L]12 or [L]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 2-1/2 to 2-3/4 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, 17-1/2 c.) 21-3/4 c. Soluble phosphoric acid 10 c. Reverted " " 8 c. Insoluble " " 2 c. Potash, as sulphate and phosphate 7-1/2 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, [L]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, 7-1/2 per cent of ammonia, and 14 per cent of phosphoric acid. Its value at the present rates we may estimate as follows:

Ammonia, 7-1/2 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. Voelcker, at the same meeting remarked: "Many soils contained from 1-1/2 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 1-1/2 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.



CHAPTER XL.

RESTORING FERTILITY TO THE SOIL.

By Sir J. B. Lawes, Bart., LL.D., F.R.S., Rothamsted, Eng.

A relation of mine, who already possessed a very considerable estate, consisting of light land, about twenty years ago purchased a large property adjoining it at a very high price. These were days when farmers were flourishing, and they no more anticipated what was in store for them in the future, than the inhabitants of the earth in the days of Noah.

Times have changed since then, and bad seasons, low prices of wheat, and cattle-disease, have swept off the tenants from these two estates, so that my relation finds himself now in the position of being the unhappy owner and occupier of five or six farms, extending over several thousand acres—one farm alone occupying an area of two thousand four hundred acres. Fortunately for the owner, he possesses town property in addition to his landed estates, so that the question with him is not, as it is with many land owners, how to find the necessary capital to cultivate the land, but, having found the capital, how to expend it in farming, so as to produce a proper return.

It is not very surprising that, under these circumstances, my opinion should have been asked. What, indeed, would have been the use of a relation, who not only spent all his time in agricultural experiments, but also pretended to teach our neighbors how to farm on the other side of the Atlantic, if he could not bring his science to bear on the land of an adjoining county! Here is the land—my relation might naturally say—here is the money, and I have so much confidence in your capacity that I will give you carte-blanche to spend as much as you please—what am I to do?

An inspection of the property brought out the following facts—that all the land was very light, and that you might walk over the fresh plowed surface in the wettest weather without any clay sticking to your boots: still a portion of the soil was dark in color, and therefore probably contained a sufficient amount of fertility to make cultivation profitable, provided the management could be conducted with that care and economy which are absolute essentials in a business where the expenditure is always pressing closely upon the income.

Upon land of this description meat-making is the backbone of the system, which must be adopted, and a large breeding flock of sheep the first essential towards success.

Science can make very little improvement upon the four-course rotation—roots, barley, clover, and wheat, unless, perhaps, it may be by keeping the land in clover, or mixed grass and clover, for two or three years.

A good deal of the land I was inspecting was so light, that, in fact, it was hardly more than sand, and for some years it had been left to grow anything that came up, undisturbed by the plow.

To a practised eye, the character of the natural vegetation is a sure indication of the fertility of the soil. Where herds of buffaloes are to be seen—their sides shaking with fat—it is quite evident that the pastures upon which they feed cannot be very bad; and in the same way, where a rank growth of weeds is found springing up upon land that has been abandoned, it may be taken for certain that the elements of food exist in the soil. This ground was covered with vegetation, but of the most impoverished description, even the "Quack" or "Couch-grass" could not form a regular carpet, but grew in small, detached bunches; everything, in fact, bore evidence of poverty.

Possibly, the first idea which might occur to any one, on seeing land in this state, might be: Why not grow the crops by the aid of artificial manures?

Let us look at the question from two points of view: first, in regard to the cost of the ingredients; and, secondly, in regard to the growth of the crop.

We will begin with wheat. A crop of wheat, machine-reaped, contains, as carted to the stack, about six pounds of soil ingredients in every one hundred pounds; that is to say, each five pounds of mineral matter, and rather less than one pound of nitrogen, which the plant takes from the soil, will enable it to obtain ninety-four pounds of other substances from the atmosphere. To grow a crop of twenty bushels of grain and two thousand pounds of straw, would require one hundred and sixty pounds of minerals, and about thirty-two pounds of nitrogen; of the one hundred and sixty pounds of minerals, one-half would be silica, of which the soil possesses already more than enough; the remainder, consisting of about eighty pounds of potash and phosphate, could be furnished for from three to four dollars, and the thirty-two pounds of nitrogen could be purchased in nitrate of soda for six or eight dollars. The actual cost of the ingredients, therefore, in the crop of twenty bushels of wheat, would be about ten to twelve dollars. But as this manure would furnish the ingredients for the growth of both straw and grain, and it is customary to return the straw to the land, after the first crop, fully one-third of the cost of the manure might, in consequence, be deducted, which would make the ingredients of the twenty bushels amount to six dollars. Twenty bushels of wheat in England would sell for twenty-eight dollars; therefore, there would be twenty-two dollars left for the cost of cultivation and profit.

A French writer on scientific agriculture has employed figures very similar to the above, to show how French farmers may grow wheat at less than one dollar per bushel. At this price they might certainly defy the competition of the United States. It is one thing, however, to grow crops in a lecture room, and quite another to grow them in a field. In dealing with artificial manures, furnishing phosphoric acid, potash, and nitrogen, we have substances which act upon the soil in very different ways. Phosphate of lime is a very insoluble substance, and requires an enormous amount of water to dissolve it. Salts of potash, on the other hand, are very soluble in water, but form very insoluble compounds with the soil. Salts of ammonia and nitrate of soda are perfectly soluble in water. When applied to the land, the ammonia of the former substance forms an insoluble compound with the soil, but in a very short time is converted into nitrate of lime; and with this salt and nitrate of soda, remains in solution in the soil water until they are either taken up by the plant or are washed away into the drains or rivers.

Crops evaporate a very large amount of water, and with this water they attract the soluble nitrate from all parts of the soil. Very favorable seasons are therefore those in which the soil is neither too dry nor too wet; as in one case the solution of nitrate becomes dried up in the soil, in the other it is either washed away, or the soil remains so wet that the plant cannot evaporate the water sufficiently to draw up the nitrates which it contains.

The amount of potash and phosphoric acid dissolved in the water is far too small to supply the requirements of the plant, and it is probable that what is required for this purpose is dissolved by some direct action of the roots of the plant on coming in contact with the insoluble phosphoric acid and potash in the soil.

In support of this view, I may mention that we have clear evidence in some of our experiments of the wheat crop taking up both phosphates and potash that were applied to the land thirty years ago.

To suppose, therefore, that, if the ingredients which exist in twenty bushels of wheat and its straw, are simply applied to a barren soil, the crop will be able to come in contact with, and take up these substances, is to assume what certainly will not take place.

I have often expressed an opinion that arable land, could not be cultivated profitably by means of artificial manures, unless the soil was capable of producing, from its own resources, a considerable amount of produce; still the question had never up to this time come before me in a distinct form as one upon which I had to decide one way or the other. I had, however, no hesitation in coming to the conclusion, that grain crops could never be grown at a profit upon my relation's land, and that consequently, for some years, it would be better to give up the attempt, and try to improve the pasture.

After what I have said about the insolubility of potash and phosphoric acid, it may possibly be asked—why not give a good dose of these substances at once, as they do not wash out of the soil—say enough to grow sixty crops of grain, and apply the nitrate, or ammonia every year in just sufficient amounts to supply the wants of the crop?

The objections to this plan are as follows: assuming the most favorable conditions of climate, and the largest possible produce, the wheat could certainly not take up the whole of the thirty-two pounds of nitrogen applied, and the crop which requires nearly one pound of nitrogen in every one hundred pounds of gross produce, would be certainly less than three thousand two hundred pounds, if supplied with only thirty-two pounds of nitrogen. If we take the total produce of the best and worst wheat crop, grown during the forty years of our experiments, we shall arrive at a better understanding in the matter. The following are the figures:

Weight of Dry Produce of Wheat Per Acre.

Straw and Grain. 1863 9330 lbs. 1879 3859 "

In order to ascertain the increase due to the nitrogen of the salts of ammonia or nitrate of soda, we must deduct from the crop the produce obtained, where mineral manures without nitrogen were used. In 1863 this amount was three thousand pounds, and in 1879 it was one thousand two hundred pounds. Deducting these amounts from the gross produce in each case, leaves six thousand three hundred and thirty as the produce due to the nitrogen in the season of 1863, and two thousand six hundred and fifty-nine as the produce due to the nitrogen in 1879.

But in each case we applied the same amount of nitrogen, eighty-seven pounds; and as the amount of nitrogen in a wheat crop, as carted from the field, contains less than one per cent. of nitrogen, it is evident that if all that was contained in the manure had been taken up by the plant, the increased crop should have weighed eight thousand seven hundred pounds instead of six thousand three hundred and thirty. Thus even in our best year, some of the nitrogen applied failed to produce growth; and when we come to the bad year we find that only twenty-six and a half pounds were taken up out of the eighty-seven pounds applied, thus leaving more than two-thirds of the whole unaccounted for.

Seasons are only occasionally either very bad or very good. What we call an average season does not differ very much from the mean of the best and worst years, which in this case would be represented by a crop of four thousand four hundred and ninety-four pounds, containing nearly forty-five pounds of nitrogen. I may say that, although I have employed one per cent. to avoid fractions in my calculations, strictly speaking three-quarters of a per cent. would more nearly represent the real quantity. If, however, on the average, we only obtain about forty-five pounds from an application of about eighty-seven pounds of nitrogen, it is evident that not more than one-half of the amount applied enters into the crop.

Now in dealing with a substance of so costly a nature as ammonia, or nitrate of soda—the nitrogen contained in which substances cannot cost much less than twenty-five cents per pound by the time it is spread upon the land, it becomes a question of importance to know what becomes of the other half, or the residue whatever it may be, which has not been taken up by the crop. Part is undoubtedly taken up by the weeds which grow with the wheat, and after the wheat has been cut. Part sinks into the sub-soil and is washed completely away during the winter.

I, myself, am disposed to think that the very great difference in the size of the Indian corn crops, as compared with the wheat crops in the States, is partly accounted for by their greater freedom from weeds, which are large consumers of nitric acid, and, in the case of the wheat crop, frequently reduce the yield by several bushels per acre. It must, however, be borne in mind that, though the wheat is robbed of its food where there are weeds, still if there were no weeds, the amount of nitric acid which the crop could not get hold of, would, in all probability, be washed out of the soil during the ensuing winter. I come to the conclusion, therefore, that the nitrogen alone, which would be required to produce one bushel of wheat, would cost not much less than fifty cents; and that, in consequence, wheat-growing by means of artificial manures, will not pay upon very poor land.

I have said that the land, about which I was consulted, had not been plowed for several years, and that although nature had done all she could to clothe the soil with vegetation, the most disheartening feature in the case was, the poverty of the weeds. A thistle may be a giant or a dwarf, according to circumstances; here they were all dwarfs. The plaintain, which I believe is sometimes sown in these districts for food, has a very deep root; here the plants were abundant, but the leaves were very small and lay so close to the ground, that, as the manager informed me, "the sheep were often injured from the amount of sand which they swallowed with the leaves when feeding."

At Rothamsted, the analyses of the rain water passing through the ordinary soil of one of my fields, which has been kept free from vegetation, have shown that the amount of nitric acid liberated in a soil, and washed out each year, is very large. Taking the ten years during which these special experiments have been in progress, I should think that the loss of nitrogen would be equal to, or possibly exceed, the amount of that substance removed by the average crops grown in the United States.

The results obtained by the rain gauges, are further completely confirmed by those in an adjoining field, where wheat and fallow have been grown alternately for twenty-seven years. The liberation of nitric acid, during the year of rest, produced for a time a large growth of wheat, but it was done at a very great waste of the fertility of the soil, and the produce is now, in proportion, considerably lower than that grown on the continuously unmanured land.

These results, if they are to be accepted as correct, must bring about a very considerable change in the generally received views in regard to fertility. We not only see more clearly the connection between a former vegetation and the stored up fertility in our soil, but we also see the importance of vegetation at the present day, as the only means by which the loss of nitric acid is prevented. The more completely the land is covered with vegetation, and the more growth there is, the greater will be the evaporation of water, and the less will be the loss of nitric acid by drainage.

I was not at all surprised to find, that the surface soil of a wood on my farm, was poorer in nitrogen than the soil of an old permanent pasture, to which no manure had been applied for twenty-five years, though during the whole period, the crop of hay had been removed every year from the land. The wood to which I refer is covered with oak, centuries old, and the foliage is so dense that but little underwood or other vegetation can grow beneath it. If both the wood and the pasture were put into arable cultivation, I have no doubt that the pasture would prove much more fertile than the wood land.

In our experiments on permanent pasture, it has been observed that the character of the herbage is mainly dependent on the food supplied. Weeds, and inferior grasses, can hold their own as long as poverty exists, but with a liberal supply of manure, the superior grasses overgrow and drive out the bad grasses and weeds. In consequence of the low price of wheat a good deal of land in England has been laid down to permanent pasture, and much money has been spent in cleaning the land preparatory to sowing the grass-seeds. I have on more occasions than one, suggested that the money employed in this process would be better expended in manure, by which the weeds would be "improved" off the face of the land. While walking over the abandoned portion of these estates I explained my views upon this point to the manager. They were, however, received with the usual skepticism, and the rejoinder that "there was only one way of getting rid of the weeds, which was by the plow and fire."

There is nothing that speaks to me so forcibly as color in vegetation; when travelling by rail, I do not require to be told that such a farm is, or is not, in high condition, or that we are passing through a fertile or infertile district. There is a peculiar green color in vegetation which is an unmistakable sign that it is living upon the fat of the land. I need hardly say that, in this case, the color of the vegetation gave unmistakable signs of the poverty of the soil; but in the midst of the dingy yellowish-green of the herbage, I came upon one square of bright green grass. In answer to my enquiry I was told that, a "lambing-fold had been there last year," and my informant added his opinion, "that the manure would be so strong that it would kill anything!" It had certainly killed the weeds, but in their place, some good grasses had taken possession of the soil.

The plan I proposed to adopt was, to spend no more money on tillage operations, but to endeavor to improve the pasture by giving to it the food necessary to grow good grasses, sowing at the same time a small quantity of the best seeds. I further suggested that a flock of sheep should be allowed to run over the whole of the land by day, and be folded there every night—about one pound of cotton-seed cake per head being allowed daily. By this means, as the fold would be moved every day, the amount of manure deposited on the soil could be estimated.

If there were a hundred sheep, receiving one pound of decorticated cotton-seed cake per head, daily, and the hurdles were arranged to enclose a space of twenty-five by twenty yards, in the course of ten days an acre of land would have received manure from one thousand pounds of cake; which amount would supply seventy-seven pounds of nitrogen, sixty-eight pounds of phosphate of lime, and thirty-two pounds of potash. This amount of cake would cost about sixteen dollars.

As regards the value of the cake as a food, it is somewhat difficult to form an estimate; but it takes nine or ten pounds of dry food—say roots, cake, and hay—to produce an increase of one pound of live weight in sheep. The cake has certainly a higher feeding value, than either hay or roots, but I will here give it only the same value, and consider that one hundred and ten pounds of increase of the animal was obtained by the consumption of the one thousand pounds of cake. The value of the increase of the live weight would be in England fully eleven dollars, leaving five dollars as the cost of the manure. Now the cake furnished seventy-seven pounds of nitrogen alone, which, if purchased in an artificial manure, would have cost nineteen dollars; and the other substances supplied by the cake, would have cost from four to five dollars more. The manures required, therefore, would be obtained much more cheaply by this than by any other process.

Labor would be saved by not cultivating the land. Manure would be saved by substituting vegetation which grows under or above ground, almost all the year round. And, by feeding the stock with cake, the necessary fertility would be obtained at the lowest possible cost.

It is probable that the land would require this treatment to be repeated for several years, before there would be a fair growth of grass. The land might then be broken up and one grain crop be taken, then it might again be laid down to grass.

Hitherto, I have considered a case where fertility is almost absent from the land, this, however, is an exception, as agriculture generally is carried on upon soils which contain large stores of fertility, though they may be very unequally distributed. By analysis of the soil we can measure the total amount of fertility which it contains, but we are left in ignorance in regard to the amount of the ingredients which are in such a form that the crops we cultivate can make use of them.

At Rothamsted, among my experiments on the growth of continuous wheat, at the end of forty years, the soil supplied with salts of ammonia has yielded, during the whole time, and still continues to yield, a larger produce than is obtained by a liberal supply of phosphates and alkaline salts without ammonia.

When we consider that every one hundred pounds of wheat crop, as carted to the stack, contains about five per cent. of mineral matter, and one per cent. of nitrogen, it is impossible to avoid the conclusion that my soil has a large available balance of mineral substances which the crop could not make use of for want of nitrogen. The crop which has received these mineral manures now amounts to from twelve to thirteen bushels per acre, and removes from the land about sixteen pounds of nitrogen every year.

Analyses of the soil show that, even after the removal of more than thirty crops in succession, without any application of manure containing ammonia, the soil still contains some thousands of pounds of nitrogen. This nitrogen is in combination with carbon; it is very insoluble in water, and until it becomes separated from the carbon, and enters into combination with oxygen, does not appear to be of any use to the crop.

The combination of nitrogen with oxygen, is known as nitric acid. The nitric acid enters into combination with the lime of the soil, and in this form becomes the food of plants.

From its great importance in regard to the growth of plants, nitric acid might be called the main spring of agriculture, but being perfectly soluble in water, it is constantly liable to be washed out of the soil. In the experiment to which I have referred above—where wheat is grown by mineral manures alone—we estimate that, of the amount of nitric acid liberated each year, not much more than one-half is taken up by the crop.

The wheat is ripe in July, at which time the land is tolerably free from weeds; several months, therefore, occur during which there is no vegetation to take up the nitric acid; and even when the wheat is sown at the end of October, much nitric acid is liable to be washed away, as the power of the plant to take up food from the soil is very limited until the spring.

The formation of nitric acid, from the organic nitrogen in the soil, is due to the action of a minute plant, and goes on quite independent of the growth of our crops. We get, however, in the fact an explanation of the extremely different results obtained by the use of different manures. One farmer applies lime, or even ground limestone to a soil, and obtains an increase in his crops; probably he has supplied the very substance which has enabled the nitrification of the organic nitrogen to increase; another applies potash, a third phosphates; if either of these are absent, the crops cannot make use of the nitric acid, however great may be the amount diffused through the soil.

It may possibly be said that the use of mineral manures tends to exhaust the soil of its nitrogen; this may, or may not, be true; but even if the minerals enable the crop to take up a larger amount of the nitric acid found in the soil year by year, this does not increase the exhaustion, as the minerals only tend to arrest that which otherwise might be washed away.

We must look upon the organic nitrogen in the soil, as the main source of the nitrogen which grows our crops. Whatever may be the amount derived from the atmosphere, whether in rain, or dew; or from condensation by the soil, or plants, it is probable that, where the land is in arable cultivation, the nitrogen so obtained, is less than the amount washed out of the soil in nitric acid. Upon land which is never stirred by the plow, there is much less waste and much less activity.

The large increase in the area of land laid down to permanent pasture in England, is not due alone to the fall in the price of grain. The reduction of fertility in many of the soils, which have been long under the plow, is beginning to be apparent. Under these circumstances a less exhausting course of treatment becomes necessary, and pasture, with the production of meat, milk, and butter, takes the place of grain fields.



APPENDIX.

Letter from Edward Jessop, York, Pa.

YORK, PA., March 16, 1876.

Joseph Harris, Esq., Moreton Farm, Rochester, N.Y.:

DEAR SIR—Your favor of the 22d of last month came safely to hand, and I am truly obliged to you for the reply to my question.—You ask, can I help you with facts or suggestions, on the subject of manure? I fear not much; but it may be useful to you to know what others need to know. I will look forward to the advent of "Talks on Manures" with much interest, hoping to get new light on a subject second to none in importance to the farmer.

I have done a little at composting for some years, and am now having a pile of about forty cords, made up of stable-manure and earth taken from the wash of higher lands, turned and fined. The labor of digging and hauling the earth, composting in thin layers with manure, turning, and fining, is so great, I doubt whether it pays for most farm crops—this to be used for mangel-wurzel and market-garden.

The usual plan in this county is to keep the stable-manure made during winter, and the accumulation of the summer in the barn-yard, where it is soaked by rain, and trampled fine by cattle, and in August and September is hauled upon ground to be seeded with wheat and grass-seeds. I do not think there is much piling and turning done.

My own conclusions, not based on accurate experiments, however, are, that the best manure I have ever applied was prepared in a covered pit on which cattle were allowed to run, and so kept well tramped—some drainage into a well, secured by pouring water upon it, when necessary, and the drainage pumped and distributed over the surface, at short intervals, particularly the parts not well tramped, and allowed to remain until it became a homogeneous mass, which it will do without having undergone so active a fermentation as to have thrown off a considerable amount of gas.

The next best, composting it with earth, as above described, piled about five or six feet high, turned as often as convenient, and kept moist enough to secure fermentation.

Or, to throw all the manure as made into a covered pit, until it is thoroughly mixed and made fine, by allowing hogs to run upon it and root at will; and when prepared for even spreading, apply it as a top-dressing on grass-land—at any convenient time.

As to how many loads of fresh manure it takes to make one of well-rotted manure, it may be answered approximately, three to one, but that would depend a good deal on the manner of doing it, and the amount of rough material in it. If well trodden by cattle under cover, and sufficient drainage poured over it, to prevent any violent fermentation, the loss of weight, I think, would not be very great, nor the bulk lessened over one-half.

Many years ago an old and successful farmer said to me, "if you want to get the full benefit of manure, spread it as a top-dressing on some growing crop," and all my experience and observation since tend to confirm the correctness of his advice.

While on this subject, allow me to protest against the practice of naming the quantity of manure applied to a given space, as so many loads, as altogether too indefinite. The bushel or cord is a definite quantity, which all can understand.

The average price of good livery stable horse-manure at this place has been for several years four dollars a cord.

With two and a half miles to haul, I am trying whether keeping a flock of 50 breeding ewes, and feeding liberally with wheat bran, in addition to hay and pasture, will not produce the needed manure more cheaply.

Respectfully yours,

EDWARD JESSOP.

P.S.—You ask for the average weight of a cord of manure, such as we pay four dollars for.

I had a cord of horse-stable manure from a livery stable in York which had been all the time under cover, with several pigs running upon it, and was moist, without any excess of wet, loaded into a wagon-box holding an entire cord, or 128 cubic feet, tramped by the wagoner three times while loading.

The wagon was weighed at our hay-scales before loading, and then the wagon and load together, with a net result for the manure of 4,400 lbs. I considered this manure rather better than the average. I had another load, from a different place, which weighed over 5,000 lbs., but on examination it was found to contain a good deal of coal ashes. We never buy by the ton. Harrison Bros. & Co., Manufacturing Chemists, Philadelphia, rate barnyard-manure as worth $5.77 per ton, and say that would be about $7.21 per cord, which would be less than 1-1/2 tons to the cord. If thrown in loosely, and it happened to be very dry, that might be possible.

Waring, in his "Handy Book of Husbandry," page 201, says, he caused a cord of well-trodden livery stable manure containing the usual proportion of straw, to be carefully weighed, and that the cord weighed 7,080 lbs.

The load I had weighed, weighing 4,400 lbs., was considered by the wagoner and by myself as a fair sample of good manure. In view of these wide differences, further trials would be desirable. Dana, in his "Muck Manual," says a cord of green cow-dung, pure, as dropped, weighs 9,289 lbs.

Farmers here seldom draw manure with less than three, more generally with four horses or mules; loading is done by the purchaser. From the barn-yard, put on loose boards, from 40 to 60 bushels are about an average load.

In hauling from town to a distance of three to five miles, farmers generally make two loads of a cord each, a day's work. From the barn-yard, a very variable number, per day. In my own case, two men with three horses have been hauling six and seven loads of sixty bushels, fine compost, a distance of from one-half to three-fourths of a mile, up a long and rather steep hill, and spreading from the wagon, as hauled, upon grass-sod.

Our larger farmers often have one driver and his team, two wagons, one loading, while the other is drawn to the field; the driver slips off one of the side-boards, and with his dung-hook draws off piles at nearly equal distances, to be spread as convenient.

EDWARD JESSOP.

Letter from Dr. E. L. Sturtevant, South Framingham, Mass.

SOUTH FRAMINGHAM, MASS., April 2, 1876.

FRIEND HARRIS—Manure about Boston is sold in various ways. First, according to the number of animals kept; price varying so much, that I do not venture to name the figures. By the cord, to be trodden over while loading; never by weight, so far as I can learn—price from 0 to $12.00 per cord, according to season, and various accidental circumstances. During the past winter, manure has been given away in Boston. Handling, hauling to the railroad, and freight costing $4 per cord for carrying 30 miles out. Market-gardeners usually haul manure as a return freight on their journeys to and from market. About South Framingham, price stiff at $8 a cord in the cellar, and this may be considered the ruling suburban price. Very friendly yours,

E. LEWIS STURTEVANT.

Letter from M. C. Weld.

NEW YORK, Nov. 9, 1876.

MY DEAR HARRIS—I don't know what I can write about manures, that would be of use. I have strong faith in humus, in ashes, leached and unleached, in lime, gas-lime, plaster, bones, ammonia ready formed, nitrates ready formed, not much in meat and blood, unless they are cheap. Nevertheless, they often are cheap, and produce splendid effects. I believe in sulphuric acid, with organic nitrogenous manures; the composting of meat, blood, hair, etc., with peat and muck, and wetting it down with dilute sulphuric acid. I believe in green-manuring, heartily, and in tillage, tillage, tillage. Little faith in superphosphates and compounded manures, at selling prices. Habirshaw's guano is good enough. So much for my creed. Truly yours,

M. C. WELD.

Letter from Peter Henderson.

NEW YORK, Oct. 26, 1876.

Mr. Joseph Harris:

DEAR SIR—If you will refer to my work "Gardening for Profit," New Edition, page 34, you will get about all the information I possess on Manures, except that I do not say anything about price. In a general way it might be safe to advise that whenever a ton (it is always best to speak of manures by weight) of either cow, horse, hog, or other stable-manure can be laid on the ground for $3, it is cheaper than commercial fertilizers of any kind at their usual market rates. This $3 per ton, I think, would be about the average cost in New York, Boston, or Philadelphia. We never haul it on the ground until we are ready to plow it in. If it has to be taken from the hog or cattle yards, we draw it out into large heaps, convenient to where it is to be put on the land, turning it, to keep it from burning or "fire-fanging," if necessary. None of our farmers or market-gardeners here keep it under cover. The expense of such covering and the greater difficulties in getting at it, for the immense quantities we use, would be greater than the benefits to be derived from keeping it under cover—benefits, in fact, which, I think, may be greatly overrated. Very truly yours,

PETER HENDERSON.

Letter from J. M. B. Anderson, Ed. "Canada Farmer," Toronto.

"CANADA FARMER" OFFICE, TORONTO, March 29, 1876.

J. Harris, Esq.:

DEAR SIR—Yours of the 25th inst. is to hand, and I shall be most happy to render you any assistance in my power. The work you undertake is in able hands, and I have every confidence that, when completed, it will form an invaluable acquisition to the agricultural literature of the day.

Manure in this city is usually sold by the two-horse load—about 1-1/2 tons—at the rate of $1 per load, or 66 cents per ton. The load contains just about a cord of manure, consequently a cord will weigh about 1-1/2 tons.

With reference to the general management of manure in Canada, I may say that the system followed differs in no material respect from that of New York and the other Eastern States. It is usually kept over winter in the open barn yard (rarely under cover, I am sorry to say), laid out on the land about the time of disappearance of last snow, and plowed in. In some cases it is not carted out until the land is ready for immediate plowing. With some of our more advanced farmers, the system has lately been adopted of keeping manure under cover and sprinkling it thoroughly at intervals with plaster and other substances. Tanks are also becoming more common than formerly, for the preservation of liquid manure, which is usually applied by means of large, perforated hogs-heads, after the manner of street-watering.

You ask, how the manure is managed at Bow Park, Brantford. That made during fall and winter is carefully kept in as small bulk as possible, to prevent exposure to the weather. In February and March it is drawn out and put in heaps 8 feet square, and well packed, to prevent the escape of ammonia. In spring, as soon as practicable, it is spread, and plowed under immediately. Manure made in spring and summer is spread on the field at once, and plowed under with a good, deep furrow.

Very truly yours, J. M. B. ANDERSON, Ed. Canada Farmer.

MANURE STATISTICS OF LONG ISLAND.

The Manure Trade of Long Island—Letter from J. H. Rushmore.

OLD WESTBURY, Long Island, April 6, 1876.

Joseph Harris, Esq.:

DEAR SIR—The great number of dealers in manure in New York precludes accuracy, yet Mr. Skidmore (who has been testifying voluminously before the New York Board of Health in relation to manure and street dirt), assures me that the accompanying figures are nearly correct. I enclose statement, from two roads, taken from their books, and the amount shipped over the other road I obtained verbally from the General Freight Agent, and embody it in the sheet of statistics.

The Ash report I know is correct, as I had access to the books showing the business, for over ten years. I have made numerous applications, verbally, and by letter, to our largest market gardeners, but there seems to exist a general and strong disinclination to communicate anything worth knowing. I enclose the best of the replies received. Speaking for some of our largest gardeners, I may say that they cultivate over one hundred acres, and use land sufficiently near to the city to enable them to dispense with railroad transportation in bringing manure to their places and marketing crops. I have noticed that one of the shrewdest gardeners invariably composts horn-shavings and bone-meal with horse-manure several months before expecting to use it. A safe average of manure used per acre by gardeners, may be stated at ninety (90) tubs, and from two hundred to twenty hundred pounds of fertilizer in addition, according to its strength, and the kind of crop.

The following railroad manure statistics will give a generally correct idea of the age of manure, when used:

Statement of Manure Sent from Jan. 1 to Dec. 31, 1875.

Over F.N.S.&C.R.R. Over Southern R.R. January 1,531 tubs. 5,815 tubs. February 4,357 " March 740 " 12,217 " April 12,122 " 7,055 " May 7,383 " 3,049 " June 5,725 " 1,365 " July 6,473-1/2 " 685 " August 6,370-1/2 " 2,911 " September 3,197 " 14,702 " October 880 " 660 " November 512 " 840 " December 1,406 " 4,923 " ——————— —————— 46,340 tubs. 57,679 tubs.

A tub is equal to 14 bushels.

Hobson, Hurtado & Co. report the amount of Peruvian guano sold in this country last year at thirty thousand tons.

Estimated number of horses in New York city, 100,000.

Estimated product of manure per horse. Four cords.

Estimated proportion of straw to pure excrement. One-half.

Amount shipped direct from stables. Nearly all.

Amount shipped on vessels. One-half.

Length of time the unshipped manure remains in heaps. From three to four months.

Average cost per horse, annually. $3.

Greatest distance of shipment. Virginia.

Average amount shipped via L.I.R.R. 60,000 tubs.

Price of manure per tub delivered on cars or vessel. 80 cents.

Average amount put on car. 40 tubs.

Statistics of Ash Trade.—Time when ashes are delivered. From middle of June to middle of October.

Places from which they are mostly shipped. Montreal, Belleville, and Toronto (Canada).

Method of transportation. Canal boats.

Average load per boat. About 8,000 bushels.

Average amount annually sold. 360,000 bushels.

Average cost delivered to farmers. 20-1/2 cents per bushel.

Per Acre, about. Amount used by farmers for potatoes 60 tubs. " " " " " cabbage (late) 50 " " " " " " corn 12 "

Amount of guano used on Long Island, as represented by the books of Chapman & Vanwyck, and their estimate of sales by other firms, 5,000 tons.

The fertilizers used on the Island are bought almost exclusively by market gardeners or farmers, who do a little market gardening, as it is the general conviction that ordinary farm-crops will not give a compensating return for their application. Most market gardeners keep so little stock that the manure made on the place is very inconsiderable. Our dairy farmers either compost home-made manures with that from the city, spread it on the land for corn in the spring, or rot it separate, to use in the fall for wheat, on land that has been cropped with oats the same year. The manure put on for potatoes is generally estimated to enrich the land sufficient for it to produce one crop of winter grain, and from five to seven crops of grass, when it is again plowed and cultivated in rotation with, first, corn, second, potatoes or oats, and is reseeded in autumn of the same year.

Fish and fish guano are largely used on land bordering the water, and adjacent to the oil-works. The average price for guano in bulk at oil-works is $12 per ton. The average price for fish on wharf is $1.50 per thousand, and it is estimated that, as a general average, 6,000 fish make a ton of guano. The fish, when applied to corn, are placed two at each hill, and plowed under at any time after the corn is large enough to cultivate. Seaweed is highly prized by all who use it, and it will produce a good crop of corn when spread thickly on the land previous to plowing.

Very respectfully,

J. H. RUSHMORE.

Letter from John E. Backus.

NEWTOWN, Long Island, N.Y., March 2nd, 1876.

Mr. G. H. Rushmore:

DEAR SIR.—Some farmers and market-gardeners use more, and some less, manure, according to crops to be raised. I use about 30 good two-horse wagon-loads to the acre, to be applied in rows or broad-casted, as best for certain crops. I prefer old horse-dung for most all purposes. Guano, as a fertilizer, phosphate of bone and blood are very good; they act as a stimulant on plants and vegetation, and are highly beneficial to some vegetation—more valuable on poor soil than elsewhere, except to produce a thrifty growth in plants, and to insure a large crop.

By giving you these few items they vary considerably on different parts of the Island; judgment must be used in all cases and all business. Hoping these few lines may be of some avail to Mr. Harris and yourself,

I remain, yours, etc.,

JOHN E. BACKUS.

MANURE IN PHILADELPHIA.

Letter from Joseph Heacock.

JENKINTOWN, Montgomery Co., Pa., April 18th, 1876.

MY DEAR FRIEND HARRIS.—Stable-manure in Philadelphia, costs by the single four-horse-load, about $9 or $10. Mostly, the farmers who haul much of it, have it engaged by the year, and then it can be had for from $7 to $8 per load. Mostly, four horses are used, though we frequently see two and three-horse teams, and occasionally, five or six horses are used. I have never seen any kind of dung hauled but that of horses. Cow-manure would be thought too heavy to haul so long a distance. Sugar-house waste, spent hops, glue waste, etc, are hauled to a small extent. We live about 9 miles from the center of the city, and the road is very hilly, though otherwise a good one, being made of stone.

The loads vary from 2-1/2 to 3-1/2 or 4 tons for four horses, according to the dryness of the manure. The wagons are made very strong, and weigh from 1,600 lbs. to 2,300 or 2,400 lbs., according to the number of horses that are to be used to them. I cannot say how many cords there are in an average load, but probably not less than two cords to four horses. One of my neighbors has a stable engaged by the year. He pays $2.50 per ton, and averages about three tons per load, and the distance from the stable in the city to his place, can not be less than 12 miles. His team goes empty one way and of course can not haul more than a load a day. In fact, can not average that, as it would be too hard on his horses. The horses used for the purpose are large and strong. Fifteen or twenty years ago, there was kept on most farms of 75 to 100 acres, a team purposely for hauling manure from the city. But it is different now, many of the farmers using artificial manures, as it costs so much less; and others are keeping more stock, and so making their own manure. Still, there is a great deal hauled yet. And some of it to a distance of 20 miles. Though when hauled to this distance, the teams are loaded both ways. For instance, they will start to the city with a load of hay (35 to 50 cwt.), on Monday afternoon (Tuesday is the day of the Hay Market); and when they have their load of hay off on Tuesday, they load their manure and drive out five or six miles and put up for the night. Next morning they start about 3 o'clock, arriving home before noon, having been away two days. On Thursday afternoon, they start again. You can see that manuring in this way is very expensive. But farmers about here well know that if they do not manure well they raise but little. Probably about four loads are used per acre on the average. Each load is generally thrown off the wagon in one large heap near where wanted, and is allowed to lie until they use it. I can not tell how much it loses in bulk by lying in the heap.

As to what crops it is used on, farmers do not think that they could go amiss in applying it to anything except oats. But it is probably used more for top-dressing mowing land, and for potatoes, than for anything else.

The usual rotation is corn, potatoes, or oats, wheat seeded to clover and timothy, and then kept in grass from two to four years. Those who haul stable-manure, usually use bone-dust or superphosphate to a greater or less extent.

Last December I built a pig-pen, 20 ft. x 40 ft., 1-1/2 stories high. The upper story to be used for litter, etc. There is a four feet entry on the north side, running the length of the building. The remainder is divided into five pens, each 8 ft. x 16 ft. It is made so that in cold weather it can be closed up tight, while in warmer weather it can be made as open as an out-shed. I am very much pleased with it. The pigs make a great deal of manure, and I believe that it can be made much cheaper than it can be bought and hauled from Philadelphia.

JOSEPH HEACOCK, Jr.

Letter from Herman L. Routzahn.

MIDDLETOWN, Md., May 11th, 1876.

Joseph Harris, Esq.:

I herewith proceed to answer questions asked.

Wheat and corn are principal crops. Corn is fed now altogether to stock for the manure.

There is but little soiling done. The principal method of making manure is: Feeding all the corn raised, as well as hay, oats, and roots, to cattle; using wheat straw, weeds, etc., as bedding, throwing the manure in the yard (uncovered), and to cover the pile with plaster (by sowing broadcast), at least once a week. To this pile is added the manure from the hog-pens, hen-house, etc., and worked over thoroughly at least twice before using. It is then applied to corn by plowing under; to wheat, as a top-dressing. For corn it is usually hauled to the field, thrown off in heaps 25 feet each way, a cart-load making two heaps. Spread just before the plow. For wheat, spread on directly after plowing, and thoroughly harrowed in. Applied broadcast for potatoes. Composts of different kinds are made and used same as in other localities, I presume. Artificial manures are going into disrepute (justly too). This is the plan now adopted by the farmers in this county (Frederick). Where woods are accessible, leaves and mould are hauled in and added to the manure-heap; in fact, every substance that can be worked into the manure-heap is freely used. Well-rotted stable-manure is worth from $1.50 to $2.50 per cord, according to condition and locality.

Very Respectfully Yours,

HERMAN L. ROUTZAHN.

Letter from Prof. E. M. Shelton, Prof. of Agriculture, Kansas State Agricultural College.

KANSAS STATE AGRICULTURAL COLLEGE,

MANHATTAN, Kansas, May 5, 1876.

DEAR SIR.—In reply to your first question, I would say that stable-manure in this vicinity, is held in very light estimation. Indeed, by the householders of this city, and quite generally by the farmers, manure is regarded as one of those things—like drouth and grasshoppers—with which a mysterious Providence sees fit to clog the operations of the husband-man. The great bulk of the stable-manure made in this city is, every spring, carted into ravines and vacant lots—wherever, in short, with least expense it can be put out of reach of the senses.

It must not be understood by this that manure has little influence on the growing crops in Kansas. Nowhere have I seen such excellent results from application of home-made fertilizers, as in Kansas. For those sterile wastes known as "Alkali lands," and "Buffalo wallows," manure is a speedy and certain cure. During two years of severe drouth, I have noticed that wherever manure had been supplied, the crop withstood the effects of dry weather much better than where no application had been made. Four years ago, a strip across one of our fields was heavily manured; this year this field is into wheat, and a dark band that may be seen half a mile shows where this application was made.

These facts the better class of our farmers are beginning to appreciate. A few days ago, a neighbor, a very intelligent farmer, assured me that from manuring eight to ten acres every year, his farm was now in better condition than when be broke up the prairie fifteen years ago.

I know of no analysis of stable or farmyard-manure made in Kansas. Concerning the weight of manures, I can give you a few facts, having had occasion during the past winter to weigh several loads used for experimental purposes. This manure was wheeled into the barnyard, chiefly from the cattle stalls, during the winter of 1874-5. It lay in the open yard until February last, when it was weighed and hauled to the fields. I found that a wagon-box, 1-1/2 x 3 x 9 feet, into which the manure was pitched, without treading, held with slight variations, when level full, one ton. At this rate a cord would weigh very close to three tons.