Specimens 3, 4 and 5, are swamp (or heath) mucks, and have been weathered for use in flower-culture. 3 and 4 are alike, save that 3 has been weathered a year longer than 4. They contain respectively 41, 56 and 67per cent.of organic matter.
Sample 6, containing 86per cent.of organic matter, is employed as a manure with great advantage, and probably was weathered before analysis. It contained 85per cent.of organic substance.
More important to us than the circumstance that this peat contains but little or no ammonia or nitric acid, and the other contains such or such a fraction of oneper cent.of these bodies, is the grand fact that all peats may yield a good share of their nitrogen to the support of crops, when properly treated and applied.
Under the influence of Liebig's teachings, which were logically based upon the best data at the disposal of this distinguished philosopher when he wrote 25 years ago, ithas been believed that the nitrogen of a fertilizer, in order to be available, must be converted into ammonia and presented in that shape to the plant. It has been recently made clear that nitric acid, rather than ammonia, is the form of nitrogenous food which is most serviceable to vegetation, and the one which is most abundantly supplied by the air and soil. The value of ammonia is however positive, and not to be overlooked.
When peat, properly prepared by weathering or composting, is suitably incorporated with a poor or light soil, it slowly suffers decomposition and wastes away. If it be wet, and air have access in limited quantity, especially iflimebe mixed with it, a portion of its nitrogen is gradually converted into ammonia. With full access of airnitric acidis produced. In either case, it appears that a considerable share of the nitrogen escapes in the free state as gas, thereby becoming useless to vegetation until it shall have become converted again into ammonia or nitric acid. It happens in a cultivated soil that the oxygen of the air is in excess at the surface, and less abundant as we go down until we get below organic matters: it happens that one day it is saturated with water more or less, and another day it is dry, so that at one time we have the conditions for the formation of ammonia, and at another, those favorable to producing nitric acid. In this way, so far as our present knowledge warrants us to affirm, organic matters, decaying in the soil, continuously yield portions of their nitrogen in the forms of ammonia and nitric acid for the nourishment of plants.
The farmer who skillfully employs as a fertilizer a peat containing a good proportion of nitrogen, may thus expect to get from it results similar to what would come from the corresponding quantity of nitrogen in guano or stable manure.
But the capacity of peat for feeding crops with,nitrogen appears not to stop here. Under certain conditions,the free nitrogen of the air which cannot be directly appropriated by vegetation, is oxidized in the pores of the soil to nitric acid, and thus, free of expense to the farmer, his crops are daily dressed with the most precious of all fertilizers.
This gathering of useless nitrogen from the air, and making it over into plant-food cannot go on in a soil destitute of organic matter, requires in fact that vegetable remains or humified substances of some sort be present there. The evidence of this statement, whose truth was maintained years ago as a matter of opinion by many of the older chemists, has recently become nearly a matter of demonstration by the investigations of Boussingault and Knop, while the explanation of it is furnished by the researches of Schœnbein and Zabelin. To attempt any elucidation of it here would require more space than is at our disposal.
It is plain from the contents of this paragraph that peat or swamp muck is, in general, an abundant source of nitrogen, and is often therefore an extremely cheap means of replacing the most rare and costly fertilizers.
II.—With regard to theinorganic matters of peatconsidered as food to plants, it is obvious, that, leaving out of the account for the present, some exceptional cases, they are useful as far as they go.
In the ashes of peats, we almost always find small quantities of sulphate of lime, magnesia and phosphoric acid. Potash and soda too, are often present, though rarely to any considerable amount. Carbonate and sulphate of lime are large ingredients of the ashes of about one-half, of the thirty-three peats and swamp mucks I have examined. The ashes of the other half are largely mixed with sand and soil, but in most cases also containconsiderable sulphate of lime, and often carbonates of lime and magnesia.
In one swamp-muck, from Milford, Conn., there was found but twoper cent.of ash, at least one-half of which was sand, and the remainder sulphate of lime, (gypsum.) In other samples 20, 30, 50 and even 60per cent.remained after burning off the organic matter. In these cases the ash is chiefly sand. The amount of ash found in those peats which were most free from sand, ranges from five to nineper cent.Probably the average proportion of true ash, viz.: that derived from the organic matters themselves, not including sand and accidental ingredients, is not far from fiveper cent.
In twenty-two specimens of European peat, examined by Websky, Jæckel, Walz, Wiegmann, Einhof and Berthier, eleven contained from 0.6 to 3.5per cent.of ash. The other eleven yielded from 5.3 to 22per cent.The average of the former was 2.4, that of the latter 12.7per cent.Most of these contained a considerable proportion of sand or soil.
Variation in the composition as well as in the quantity of ash is very great.
Three analyses of peat-ashes have been executed at the author's instance with the subjoined results:
ANALYSIS OF PEAT-ASHES.
A.B.C.Potash0.690.803.46Soda0.58-trace.Lime40.5235.596.60Magnesia6.064.921.05Oxide of iron and alumina5.179.0815.59Phosphoric acid0.500.771.55Sulphuric acid5.5210.414.04Chlorine0.150.430.70Soluble silica8.231.40 }Carbonic acid19.6022.28 }67.01Sand12.1115.04 }99.13100.74100.00
A was furnished by Mr. Daniel Buck, Jr., of Poquonock, Conn., and comes from a peat which he uses as fuel.
B was sent by Mr. J. H. Stanwood, of Colebrook, Conn.
C was sent from Guilford, Conn., by Mr. Andrew Foote.[5]
A and B, after excluding sand, are seen to consist chiefly of carbonates and sulphates of lime and magnesia. III. contains a very large proportion of sand and soluble silica, much iron and alumina, less lime and sulphuric acid. Potash and phosphoric acid are three times more abundant in C than in the others.
Instead of citing in full the results of Websky, Jæckel and others, it will serve our object better to present the maximum, minimum and average proportions of the important ingredients in twenty-six recent analyses, (including these three,) that have come under the author's notice.
VARIAIONS AND AVERAGES IN COMPOSITION OF PEAT-ASHES
Minimum.Maximum.Average.Potash0.05to3.640.89 per cent.Sodanoneto5.730.83 per cent.Lime4.72to58.3824.00 per cent.Magnesianoneto24.393.20 per cent.Alumina0.90to20.505.78 per cent.Oxide of ironnoneto73.3318.70 per cent.Sulphuric acidnoneto37.407.50 per cent.Chlorinenoneto6.500.60 per cent.Phosphoric acidnoneto6.292.56 per cent.Sand0.99to56.9725.50 per cent.
It is seen from the above figures that the ash of peat varies in composition to an indefinite degree. Lime is the only ingredient that is never quite wanting, and with the exception of sand, it is on the average the largest. Of the other agriculturally valuable components, sulphuric acid has the highest average; then follows magnesia; then phosphoric acid, and lastly, potash and soda: all of these, however, may be nearly or quite lacking.
Websky, who has recently made a study of the composition of a number of German peats, believes himself warranted to conclude that peat is so modified in appearance by its mineral matters, that the quantity or character of the latter may be judged of in many cases by the eye. He remarks, (Journal fuer Praktische Chemie, Bd. 92, S. 87,) "that while for example the peats containing much sand and clay have a red-brown powdery appearance, and never assume a lustrous surface by pressure; those which are very rich in lime, are black, sticky when moist, hard and of a waxy luster on a pressed surface, when dry: a property which they share indeed with very dense peats that contain little ash. Peats impregnated with iron are easily recognized. Their peculiar odor, and their changed appearance distinguish them from all others."
From my own investigations on thirty specimens of Connecticut peats, I am forced to disagree with Websky entirely, and to assert that except as regards sand, which may often be detected by the eye, there is no connection whatever between the quantity or character of the ash and the color, consistency, density or any other external quality of the peat.
The causes of this variation in the ash-content of peat, deserve a moment's notice. The plants that produce peat contain considerable proportions of lime, magnesia, alkalies, sulphuric acid, chlorine and phosphoric acid, as seen from the following analysis by Websky.
COMPOSITION OF THE ASH OF SPHAGNUM.
Potash17.2Soda8.3Lime11.8Magnesia6.7Sulphuric acid6.5Chlorine6.2Phosphoric acid6.7Per cent.of ash, 2.5.
The mineral matters of the sphagnum do not allbecome ingredients of the peat; but, as rapidly as the moss decays below, its soluble matters are to a great degree absorbed by the vegetation, which is still living and growing above. Again, when a stream flows through a peat-bed, soluble matters are carried away by the water, which is often dark-brown from the substances dissolved in it. Finally the soil of the adjacent land is washed or blown upon the swamp, in greater or less quantities.
III.—The decomposition of peat in the soil offers some peculiaritiesthat are worthy of notice in this place. Peat is more gradual and regular in decay than the vegetable matters of stable dung, or than that furnished by turning under sod or green crops. It is thus a more steady and lasting benefit, especially in light soils, out of which ordinary vegetable manures disappear too rapidly. The decay of peat appears to proceed through a regular series of steps. In the soil, especially in contact with soluble alkaline bodies, as ammonia and lime, there is a progressive conversion of theinsolubleorless solubleintosolublecompounds. Thus the inert matters that resist the immediate solvent power of alkalies, absorb oxygen from the air, and form the humic or ulmic acids soluble in alkalies; the humic acids undergo conversion into crenic acid, and this body, by oxidation, passes into apocrenic acid. The two latter are soluble in water, and, in the porous soil, they are rapidly brought to the end-results of decay, viz.: water, carbonic acid, ammonia and free nitrogen.
Great differences must be observed, however, in the rapidity with which these changes take place. Doubtless they go on most slowly in case of the fibrous compact peats, and perhaps some of the lighter and more porous samples of swamp muck, would decay nearly as fast as rotted stable dung.
It might appear from the above statement, that theeffect of exposing peat to the air, as is done when it is incorporated with the soil, would be to increase relatively the amount of soluble organic matters; but the truth is, that they are often actually diminished. In fact, the oxidation and consequent removal of these soluble matters (crenic and apocrenic acids,) is likely to proceed more rapidly than they can be produced from the less soluble humic acid of the peat.
IV.—Comparison of Peat with Stable Manure.
The fertilizing value of peat is best understood by comparing it with some standard manure. Stable manure is obviously that fertilizer whose effects are most universally observed and appreciated, and by setting analyses of the two side by side, we may see at a glance, what are the excellencies and what the deficiencies of peat. In order rightly to estimate the worth of those ingredients which occur in but small proportion in peat, we must remember that it, like stable manure, may be, and usually should be, applied in large doses, so that in fact the smallest ingredients come upon an acre in considerable quantity. In making our comparison, we will take the analysis of Peat from the farm of Mr. Daniel Buck, Jr., of Poquonock, Conn., and the average of several analyses of rotted stable dung ofgood quality.
No.I, is the analysis of Peat; No.II, that of well rotted stable manure:—
I.II.Water expelled at 212 degrees79.00079.00Organic matter.{Soluble in dilute solution of carbonate of soda7.312 }14.16{Insoluble in solution of carbonate of soda12.210 }Potash0.0100.65Soda0.009-Lime0.6080.57Magnesia0.0910.19Phosphoric acid0.0080.23Sulphuric acid0.0820.27Nitrogen0.6000.55Matters, soluble in water0.4504.42
To make the comparison as just as possible, the peat iscalculated with the same content of water, that stable dung usually has.
We observe then, that the peat contains in a given quantity,about one-third more organic matter, an equal amount of lime and nitrogen; but isdeficient in potash, magnesia, phosphoric and sulphuric acids.
The deficiencies of this peat in the matter of composition may be corrected, as regards potash, by adding to 100 lbs. of it 1 lb. of potash of commerce, or 5 lbs. of unleached wood-ashes; as regards phosphoric and sulphuric acids, by adding 1 lb. of good superphosphate, or 1 lb. each of bone dust and plaster of Paris.
In fact, the additions just named, will convertany fresh peat, containing not more than 80per cent.of water and not less than 20per cent.of organic matter, into a mixture having as much fertilizing matters as stable dung, with the possible exception of nitrogen.
It is a fact, however, that two manures may reveal to the chemist the same composition, and yet be very unlike in their fertilizing effects, because their conditions are unlike, because they differ in their degrees of solubility or availability.
As before insisted upon, it is true in general, that peat is more slow of decomposition than yard-manure, and this fact, which is an advantage in an amendment, is a disadvantage in a fertilizer. Though there may be some peats, or rather swamp mucks, which are energetic and rapid in their action, it seems that they need to be applied in larger quantities than stable manure in order to produce corresponding fertilizing effects. In many cases peat requires some preparation by weathering, or by chemical action—"fermentation"—induced by decomposing animal matters or by alkalies. This topic will shortly be discussed.
We adopt, as a general fact, the conclusion that peat is inferior in fertilizing power to stable manure.
Experience asserts, however, with regard to some individual kinds, that they are equal to common yard manure without any preparation whatever.
Mr. Daniel Buck, of Poquonock, Conn., says, of the 'muck,' over-lying the peat, whose composition has just been compared with stable manure, that it "has been applied fresh to meadow with good results; the grass is not as tall but thicker and finer, and of a darker green in the spring, than when barn-yard manure is spread on."
A swamp muck, from Mr. A. M. Haling, Rockville, Conn., "has been used as a top-dressing, on grass, with excellent results. It is a good substitute for barn-yard manure."
A peat, from Mr. Russell U. Peck, of Berlin, Conn., "has been used fresh, on corn and meadow, with good effect."
Of the peat, from the 'Beaver Pond,' near New Haven, Mr. Chauncey Goodyear, says, "it has been largely used in a fresh state, and in this condition is as good as cow dung."
Mr. Henry Keeler, remarks, concerning a swamp muck occurring at South Salem, N. Y., that "it has been used in the fresh state, applied to corn and potatoes, and appears to be equal to good barn manure:" further:—"it has rarely been weathered more than two months, and then applied side by side with the best yard manure has given equally good results."
A few words as to the apparent contradiction between Chemistry, which says that peat is not equal to stable dung as a fertilizer, and Practice, which in these cases affirms that it is equal to our standard manure.
In the first place, the chemical conclusion is a general one, and does not apply to individual peats, which, in a few instances, may be superior to yard manure. Thepractical judgment also is, that, in general, yard manure is the best.
To go to the individual cases; second: A peat in which nitrogen exists in as large a proportion as is found in stable or yard manure, being used in larger quantity, or being more durable in its action, may for a few seasons produce better results than the latter, merely on account of the presence of this one ingredient, it may in fact, for the soil and crop to which it is applied, be a better fertilizer than yard manure, because nitrogen is most needed in that soil, and yet for the generality of soils, or in the long run, it may prove to be an inferior fertilizer.
Again; third—the melioration of the physical qualities of a soil, the amendment of its dryness and excessive porosity, by means of peat, may be more effective for agricultural purposes, than the application of tenfold as much fertilizing,i. e.plant-feeding materials; in the same way that the mere draining of an over-moist soil often makes it more productive than the heaviest manuring.
2.—On the characters of Peat that are detrimental, or that may sometimes need correction before it is agriculturally useful.
I.—Bad effects on wet heavy soils.
We have laid much stress on the amending qualities of peat, when applied to dry and leachy soils, which by its use are rendered more retentive of moisture and manure. These properties, which it would seem, are just adapted to renovate very light land, under certain circumstances, may become disadvantageous on heavier soils. On clays no application is needed to retain moisture. They are already too wet as a general thing.
Peat, when put into the soil, lasts much longer than stubble, or green crops plowed in, or than long manure.If buried too deeply, or put into a heavy soil, especially if in large quantity, it does not decay, but remains wet, and tends to make a bog of the field itself.
For soils that are rather heavy, it is therefore best to compost the peat with some rapidly fermenting manure. We thus get a compound which is quicker than muck, and slower than stable manure, etc., and is therefore better adapted to the wants of the soil than either of these would be alone.
Here it will be seen that much depends on the character of the peat itself. If light and spongy, and easily dried, it may be used alone with advantage on loamy soils, whereas if dense, and coherent, it would most likely be a poor amendment on a soil which has much tendency to become compact, and therefore does not readily free itself from excess of water.
But even a clay soil, ifthorough-drained and deeply plowed, may be wonderfully improved by even a heavy dressing of muck, as then, the water being let off, the muck can exert no detrimental action; but operates as effectually to loosen a too heavy soil, as in case of sand, it makes an over-porous soil compact or retentive. A clay may be made friable, if well drained, by incorporating with it any substance as lime, sand, long manure or muck, which interposing between the clayey particles, prevents their adhering together.
II.—Noxious ingredients.
a.Vitriol peat.Occasionally a peat is met with which is injurious if applied in the fresh state to crops, from its containing some substance which exerts a poisonous action on vegetation. The principal detrimental ingredients that occur in peat, appear to be sulphate of protoxide ofiron,—the same body that is popularly known under the names copperas and green-vitriol,—and sulphate of alumina, the astringent component of alum.
I have found these substances ready formed in large quantity in but one of the peats that I have examined, viz.: that sent me by Mr. Perrin Scarborough; of Brooklyn, Conn. This peat dissolved in water to the extent of 15per cent., and the soluble portion, although containing some organic matter and sulphate of lime, consisted in great part of green-vitriol.
Portions of this muck, when thrown up to the air, become covered with "a white crust, having the taste of alum or saltpeter."
The bed containing this peat, though drained, yields but a little poor bog hay, and the peat itself, even after weathering for a year, when applied, mixed with one-fifth of stable manure to corn in the hill, gave no encouraging results, though a fair crop was obtained. It is probable that the sample analyzed was much richer in salts of iron and alumina, than the average of the muck.
Green-vitriol in minute doses is not hurtful, but rather beneficial to vegetation; but in larger quantity it is fatally destructive.
In a salt-marsh mud sent me by the Rev. Wm. Clift, of Stonington, Conn., there was found sulphate of iron in considerable quantity.
This noxious substance likewise occurred in small amount in swamp muck from E. Hoyt, Esq., New Canaan, Conn., and in hardly appreciable quantity in several others that I have examined. Besides green-vitriol, it is possible that certain organic salts of iron, may be deleterious.
The poisonous properties of vitriol-peats may be effectually corrected by composting with lime, or wood-ashes. By the action of these substances, sulphate of lime,(plaster of Paris) is formed, while the iron separates as peroxide, which, being insoluble, is without deleterious effect on vegetation. Where only soluble organic salts of iron (crenate of iron) are present, simple exposure to the air suffices to render them innocuous.
b.The acidity of Peats.—Many writers have asserted that peat and muck possess a hurtful "acidity" which must be corrected before they can be usefully employed. It is indeed a fact, that peat consists largely of acids, but, except perhaps in the vitriol-peats, (those containing copperas,) they are so insoluble, or if soluble, are so quickly modified by the absorption of oxygen, that they do not exhibit any "acidity" that can be deleterious to vegetation. It is advised to neutralize this supposed acidity by lime or an alkali before using peat as a fertilizer or amendment, and there is great use in such mixtures of peat with alkaline matters, as we shall presently notice under the head of composts.
By the word acidity is conveyed the idea of something hurtful to plants. This something is, doubtless, in many cases, the salts of iron we have just noticed. In others, it is simply the inertness, "coldness" of the peat, which is not positively injurious, but is, for a time at least, of no benefit to the soil.
c.Resinous mattersare mentioned by various writers as injurious ingredients of peat, but I find no evidence that this notion is well-founded. The peat or muck formed from the decay of resinous wood and leaves does not appear to be injurious, and the amount of resin in peat is exceedingly small.
3.—The Preparation of Peat for Agricultural use.
a.Excavation.—As to the time and manner of getting out peat, the circumstances of each case mustdetermine. I only venture here to offer a few hints on this subject, which belongs so exclusively to the farm. The month of August is generally the appropriate time for throwing up peat, as then the swamps are usually most free from water, and most accessible to men and teams; but peat is often dug to best advantage in the winter, not only on account of the cheapness of labor, and from there being less hurry with other matters on the farm at that season, but also, because the freezing and thawing of the peat that is thrown out, greatly aid to disintegrate it and prepare it for use.
A correspondent of TheHomestead, signing himself "Commentator," has given directions for getting out peat that are well worth the attention of farmers. He says:—
"The composting of muck and peat, with our stable and barn-yard manures, is surely destined to become one of the most important items in farm management throughout all the older States at least. One of the difficulties which lie in the way, is the first removal of the muck from its low and generally watery bed; to facilitate this, in many locations, it is less expensive to dry it before carting, by beginning an excavation at the border of the marsh in autumn, sufficiently wide for a cart path, throwing the muck out upon the surface on each side, and on a floor of boards or planks, to prevent it from absorbing moisture from the wet ground beneath; this broad ditch to be carried a sufficient length and depth to obtain the requisite quantity of muck. Thus thrown out, the two piles are now in a convenient form to be covered with boards, and, if properly done, the muck kept covered till the succeeding autumn, will be found to be dry and light, and in some cases may be carted away on the surface, or it may be best to let it remain a few months longer until the bottom of the ditch has become sufficiently frozen to bear a team; it can then be more easilyloaded upon a sled or sleigh, and drawn to the yards and barn. In other localities, and where large quantities are wanted, and it lies deep, a sort of wooden railroad and inclined plane can be constructed by means of a plank track for the wheels of the cart to run upon, the team walking between these planks, and if the vehicle is inclined to 'run off the track,' it may usually be prevented by scantlings, say four inches thick, nailed upon one of the tracks on each side of the place where the wheel should run. Two or more teams and carts may now be employed, returning into the excavation outside of this track. As the work progresses, the track can be extended at both ends, and by continuing or increasing the inclination at the upper end, a large and high pile may be made, and if kept dry, will answer for years for composting, and can be easily drawn to the barn at any time."
"The composting of muck and peat, with our stable and barn-yard manures, is surely destined to become one of the most important items in farm management throughout all the older States at least. One of the difficulties which lie in the way, is the first removal of the muck from its low and generally watery bed; to facilitate this, in many locations, it is less expensive to dry it before carting, by beginning an excavation at the border of the marsh in autumn, sufficiently wide for a cart path, throwing the muck out upon the surface on each side, and on a floor of boards or planks, to prevent it from absorbing moisture from the wet ground beneath; this broad ditch to be carried a sufficient length and depth to obtain the requisite quantity of muck. Thus thrown out, the two piles are now in a convenient form to be covered with boards, and, if properly done, the muck kept covered till the succeeding autumn, will be found to be dry and light, and in some cases may be carted away on the surface, or it may be best to let it remain a few months longer until the bottom of the ditch has become sufficiently frozen to bear a team; it can then be more easilyloaded upon a sled or sleigh, and drawn to the yards and barn. In other localities, and where large quantities are wanted, and it lies deep, a sort of wooden railroad and inclined plane can be constructed by means of a plank track for the wheels of the cart to run upon, the team walking between these planks, and if the vehicle is inclined to 'run off the track,' it may usually be prevented by scantlings, say four inches thick, nailed upon one of the tracks on each side of the place where the wheel should run. Two or more teams and carts may now be employed, returning into the excavation outside of this track. As the work progresses, the track can be extended at both ends, and by continuing or increasing the inclination at the upper end, a large and high pile may be made, and if kept dry, will answer for years for composting, and can be easily drawn to the barn at any time."
b.Exposure, weathering, or seasoning of peat.—In some cases, the chief or only use of exposing the thrown-up peat to the action of the air and weather during several months or a whole year, is to rid it of the great amount of water which adheres to it, and thus reduce its bulk and weight previous to cartage.
The general effect of exposure as indicated by my analyses, is to reduce the amount of matter soluble in water, and cause peats to approach in this respect a fertile soil, so that instead of containing 2, 4, or 6per cent.of substances soluble in water, as at first, they are brought to contain but one-half these amounts, or even less. This change, however, goes on so rapidly after peat is mingled with the soil, that previous exposure on this account is rarely necessary, and most peats might be used perfectly fresh but for the difficulty often experienced, of reducing them to such a state of division as to admit of proper mixture with the soil.
The coherent peats which may be cut out in tough blocks, must be weathered, in order that the fibres of moss or grass-roots, which give them their consistency, may be decomposed or broken to an extent admitting of easy pulverization by the instruments of tillage.
The subjection of fresh and wet peat to frost, speedily destroys its coherence and reduces it to the proper state of pulverization. For this reason, fibrous peat should be exposed when wet to winter weather.
Another advantage of exposure is, to bring the peat into a state of more active chemical change. Peat, of the deeper denser sorts, is generally too inert ("sour," cold) to be directly useful to the plant. By exposure to the air it appears gradually to acquire the properties of the humus of the soil, or of stable manure, which are vegetable matters, altered by the same exposure. It appears to become more readily oxidable, more active, chemically, and thus more capable of exciting or rather aiding vegetable growth, which, so far as the soil is concerned, is the result of chemical activities.
Account has been already given of certain peats, which, used fresh, are accounted equal or nearly equal to stable manure. Others have come under the writer's notice, which have had little immediate effect when used before seasoning.
Mr. J. H. Stanwood says of a peat, from Colebrook, Conn., that it "has been used to some extent as a top-dressing for grass and other crops with satisfactory results,although no particular benefit was noticeable during the first year. After that, the effects might be seen for a number of years."
Rev. Wm. Clift observes, concerning a salt peat, from Stonington, Conn.:—"It has not been used fresh; is too acid; even potatoes do not yield wellin it the first season, without manure."
The nature of the chemical changes induced by weathering, is to some extent understood so far as the nitrogen, the most important fertilizing element, is concerned. The nitrogen of peat, as we have seen, is mostly inert, a small portion of it only, existing in a soluble or available form. By weathering, portions of this nitrogen become converted into nitric acid. This action goes on at the surface of the heap, where it is most fully exposed to the air. Below, where the peat is more moist, ammonia is formed, perhaps simply by the reduction of nitric acid—not unlikely also, by the transformation of inert nitrogen. On referring to the analyses given on page 44, it is seen, that the first two samples contain but little ammonia and no nitric acid. Though it is not stated what was the condition of these peats, it is probable they had not been weathered. The other four samples were weathered, and the weathering had been the more effectual from the large admixture of sand with them. They yielded to the analyst very considerable quantities of ammonia and nitrates.
When a peat contains sulphate of protoxide of iron, or soluble organic salts of iron, to an injurious extent, these may be converted into other insoluble and innocuous bodies, by a sufficient exposure to the air. Sulphate of protoxide of iron is thus changed into sulphate of peroxide of iron, which is insoluble, and can therefore exert no hurtful effect on vegetation, while the soluble organic bodies of peat are oxydized and either converted into carbonic acid gas, carbonate of ammonia and water, or else made insoluble.
It is not probable, however, that merely throwing up a well characterized vitriol-peat into heaps, and exposing it thus imperfectly to the atmosphere, is sufficient to correct its bad qualities. Such peats need the addition of some alkaline body, as ammonia, lime, or potash, to render them salutary fertilizers.
c.This brings us to the subject of composting, which appears to be the best means of taking full advantage of all the good qualities of peat, and of obviating or neutralizing the ill results that might follow the use of some raw peats, either from a peculiarity in their composition, (soluble organic compounds of iron, sulphate of protoxide of iron,) or from too great indestructibility. The chemical changes (oxidation ofironandorganic acids), which prepare the inert or even hurtful ingredients of peat to minister to the support of vegetation, take place most rapidly in presence of certain other substances.
The substances which rapidly induce chemical change in peats, are of two kinds, viz.: 1.—animal or vegetable matters that are highly susceptible to alteration and decay, and 2.—alkalies, eitherammoniacoming from the decomposition of animal matters, orlime,potashandsoda.
A great variety of matters may of course be employed for making or mixing with peat composts; but there are comparatively few which allow of extensive and economical use, and our notice will be confined to these.
First of all, the composting of peat withanimal manuresdeserves attention. Its advantages may be summed up in two statements.
1.—It is an easy and perfect method of economizing all such manures, even those kinds most liable to loss by fermentation, as night soil and horse dung; and,
2.—It develops most fully and speedily the inert fertilizing qualities of the peat itself.
Without attempting any explanation of the changes undergone by a peat and manure compost, further than to say that the fermentation which begins in the manure extends to and involves the peat, reducing the whole nearly, if not exactly, to the condition of well-rotted dung, and that in this process the peat effectually prevents the loss of nitrogen as ammonia,—I may appropriately givethe practical experience of farmers who have proved in the most conclusive manner how profitable it is to devote a share of time and labor to the manufacture of this kind of compost.
Preparation of Composts with Stable Manure.—The best plan of composting is to have a water tight trench, four inches deep and twenty inches wide, constructed in the stable floor, immediately behind the cattle, and every morning put a bushel-basketful of muck behind each animal. In this way the urine is perfectly absorbed by the muck, while the warmth of the freshly voided excrements so facilitates the fermentative process, that, according to Mr. F. Holbrook, Brattleboro, Vt., who has described this method,much more muck can thus be well prepared for usein the spring, than by any of the ordinary modes of composting. When the dung and muck are removed from the stable, they should be well intermixed, and as fast as the compost is prepared, it should be put into a compact heap, and covered with a layer of muck several inches thick. It will then hardly require any shelter if used in the spring.
If the peat be sufficiently dry and powdery, or free from tough lumps, it may usefully serve as bedding, or litter for horses and cattle, as it absorbs the urine, and is sufficiently mixed with the dung in the operation of cleaning the stable. It is especially good in the pig-pen, where the animals themselves work over the compost in the most thorough manner, especially if a few kernels of corn be occasionally scattered upon it.
Mr. Edwin Hoyt, of New Canaan, Conn., writes:—"Our horse stables are constructed with a movable floor and pit beneath, which holds 20 loads of muck of 25 bushels per load. Spring and fall, this pit is filled with fresh muck, which receives all the urine of the horses, and beingoccasionally worked over and mixed, furnishes us annually with 40 loads of the most valuable manure."
"Our stables are sprinkled with muck every morning, at the rate of one bushel per stall, and the smell of ammonia, etc., so offensive in most stables, is never perceived in ours. Not only are the stables kept sweet, but the ammonia is saved by this procedure."
When it is preferred to make the compost out of doors, the plan generally followed is to lay down a bed of weathered peat, say eight to twelve inches thick; cover this with a layer of stable dung, of four to eight inches; put on another stratum of peat, and so, until a heap of three to four feet is built up. The heap may be six to eight feet wide, and indefinitely long. It should be finished with a thick coating of peat, and the manure should be covered as fast as brought out.
The proportions of manure and peat should vary somewhat according to their quality and characters. Strawy manure, or that from milch-cows, will "ferment" less peat than clear dung, especially when the latter is made by horses or highly fed animals. Some kinds of peat heat much easier than others. There are peats which will ferment of themselves in warm moist weather—even in the bog, giving off ammonia in perceptible though small amount. Experience is the only certain guide as to the relative quantities to be employed, various proportions from one to five of peat for one of manure, by bulk, being used.
When the land is light and needs amending, as regards its retentive power, it is best to make the quantity of peat as large as can be thoroughly fermented by the manure.
The making of a high heap, and the keeping it trim and in shape, is a matter requiring more labor than is generally necessary. Mr. J. H. Stanwood, of Colebrook, Conn., writes me:—
"My method of composting is as follows: I draw my muck to the barn-yard, placing the loads as near together as I can tip them from the cart. Upon this I spread whatever manure I have at hand, and mix with the feet of the cattle, and heap up with a scraper."
Peat may be advantageously used to save from waste the droppings of the yard.
Mr. Edwin Hoyt, of New Canaan, Conn., says:—"We use muck largely in our barn-yards, and after it becomes thoroughly saturated and intermixed with the droppings of the stock, it is piled up to ferment, and the yard is covered again with fresh muck."
Mr. N. Hart, Jr., of West Cornwall, Conn., writes:—"In the use of muck we proceed as follows: Soon after haying we throw up enough for a year's use, or several hundred loads. In the fall, the summer's accumulation in hog-pens and barn cellars is spread upon the mowing grounds, and a liberal supply of muck carted in and spread in the bottoms of the cellars, ready for the season for stabling cattle. When this is well saturated with the drippings of the stables, a new supply is added. The accumulation of the winter is usually applied to the land for the corn crop, except the finer portion, which is used to top-dress meadow land. A new supply is then drawn in for the swine to work up. This is added to from time to time, and as the swine are fed on whey, they will convert a large quantity into valuable manure for top-dressing mowing land."
A difference of opinion exists as to the treatment of the compost. Some hold it indifferent whether the peat and manure are mixed, or put in layers when the composting begins. Others assert, that the fermentation proceeds better when the ingredients are stratified. Some direct, that the compost should not be stirred. The general testimony is, that mixture, at the outset, is as effectualas putting up in layers; but, if the manure be strawy, it is, of course, difficult or impracticable to mix at first. Opinion also preponderates in favor of stirring, during or after the fermentation.
Mr. Hoyt remarks:—"We are convinced, that the oftener a compost pile of yard manure and muck is worked over after fermenting, the better. We work it over and add to it a little more muck and other material, and the air being thus allowed to penetrate it, a new fermentation or heating takes place, rendering it more decomposable and valuable."
Rev. Wm. Clift, writes:—"Three or four loads of muck to one of stable manure, put together in the fall or winter in alternate layers, forked over twice before spreading and plowing in, may represent the method of composting."
Mr. Adams White, of Brooklyn, Conn., proceeds in a different manner. He says:—"In composting, 20 loads are drawn on to upland in September, and thrown up in a long pile. Early in the spring 20 loads of stable manure are laid along side, and covered with the muck. As soon as it has heated moderately, the whole is forked over and well mixed."
Those who have practiced making peat composts with their yard, stable, and pen manure, almost invariably find them highly satisfactory in use, especially upon light soils.
A number of years ago, I saw a large pile of compost in the farm-yard of Mr. Pond, of Milford, Conn., and witnessed its effect as applied by that gentleman to a field of sixteen acres of fine gravelly or coarse sandy soil. The soil, from having a light color and excessive porosity, had become dark, unctuous, and retentive of moisture, so that during the drouth of 1856, the crops on this field were good and continued to flourish, while on the contiguous land they were dried up and nearly ruined. Thiscompost was made from a light muck, that contained but threeper cent.of ash (more than half of which was sand), and but 1.2per cent.of nitrogen, in the air-dry state—(twentyper cent.of water). Three loads of this muck were used to one of stable manure.
Here follow some estimates of the value of this compost by practical men. They are given to show that older statements, to the same effect, cannot be regarded as exaggerated.
Mr. J. H. Stanwood, of Colebrook, Conn., says:—"Experiments made by myself, have confirmed me in the opinion that a compost of equal parts of muck and stable manure is equal to the same quantity of stable manure."
Mr. Daniel Buck, Jr., of Poquonock, Conn., remarks:—"8 loads of muck and 4 of manure in compost, when properly forked over, are equal to 12 loads of barn-yard manure on sandy soil."
Rev. Wm. Clift, of Stonington, Conn., writes:—"I consider a compost made of one load of stable manure and three of muck, equal in value to four loads of yard manure."
Mr. N. Hart, Jr., of West Cornwall, Conn., observes of a peat sent by him for analysis:—"We formerly composted it in the yard with stable manure, but have remodeled our stables, and now use it as an absorbent and to increase the bulk of manure to double its original quantity. We consider the mixture more valuable than the same quantity of stable manure." Again, "so successful has been the use of it, that we could hardly carry on our farming operations without it."
Mr. Adams White, of Brooklyn, Conn., states:—"The compost of equal bulks of muck and stable manure, has been used for corn (with plaster in the hill,) on dry sandy soil to great advantage. I consider the compost worth more per cord than the barn-yard manure."
Night Soilis a substance which possesses, when fresh, the most valuable fertilizing qualities, in a very concentrated form. It is also one which is liable to rapid and almost complete deterioration, as I have demonstrated by analyses. The only methods of getting the full effect of this material are, either to use it fresh, as is done by the Chinese and Japanese on a most extensive and offensive scale; or to compost it before it can decompose. The former method, will, it is to be hoped, never find acceptance among us. The latter plan has nearly all the advantages of the former, without its unpleasant features.
When the night soil falls into a vault, it may be composted, by simply sprinkling fine peat over its surface, once or twice weekly, as the case may require,i. e.as often as a bad odor prevails. The quantity thus added, may be from twice to ten times the bulk of the night soil,—the more within these limits, the better. When the vault is full, the mass should be removed, worked well over and after a few days standing, will be ready to use to manure corn, tobacco, etc., in the hill, or for any purpose to which guano or poudrette is applied. If it cannot be shortly used, it should be made into a compact heap, and covered with a thick stratum of peat. When signs of heating appear, it should be watched closely; and if the process attains too much violence, additional peat should be worked into it. Drenching with water is one of the readiest means of checking too much heating, but acts only temporarily. Dilution with peat to a proper point, which experience alone can teach, is the surest way of preventing loss. It should not be forgotten to put a thick layer of peat at the bottom of the vault to begin with.
Another excellent plan, when circumstances admit, is, to have the earth-floor where the night soil drops, level with the surface of the ground, or but slightly excavated,and a shed attached to the rear of the privy to shelter a good supply of peat as well as the compost itself. Operations are begun by putting down a layer of peat to receive the droppings; enough should be used to absorb all the urine. When this is nearly saturated, more should be sprinkled on, and the process is repeated until the accumulations must be removed to make room for more. Then, once a week or so, the whole is hauled out into the shed, well mixed, and formed into a compact heap, or placed as a layer upon a stratum of peat, some inches thick, and covered with the same. The quantity of first-class compost that may be made yearly upon any farm, if due care be taken, would astonish those who have not tried it. James Smith, of Deanston, Scotland, who originated our present system of Thorough Drainage, asserted, that the excrements of one man for a year, are sufficient to manure half an acre of land. In Belgium the manure from such a source has a commercial value of $9.00 gold.
It is certain, that the skillful farmer may make considerably more than that sum from it in New England,per annum. Mr. Hoyt, of New Canaan, Conn., says:—
"Our privies are deodorized by the use of muck, which is sprinkled over the surface of the pit once a week, and from them alone we thus prepare annually, enough "poudrette" to manure our corn in the hill."
Peruvian Guano, so serviceable in its first applications to light soils, may be composted with muck to the greatest advantage. Guano is an excellent material for bringing muck into good condition, and on the other hand the muck most effectually prevents any waste of the costly guano, and at the same time, by furnishing the soil with its own ingredients, to a greater or less degree prevents the exhaustion that often follows the use of guano alone. The quantity of muck should be pretty large comparedto that of the guano,—a bushel of guano will compost six, eight, or ten of muck. Both should be quite fine, and should be well mixed, the mixture should be moist and kept covered with a layer of muck of several inches of thickness. This sort of compost would probably be sufficiently fermented in a week or two of warm weather, and should be made and kept under cover.
If no more than five or six parts of muck to one of guano are employed, the compost, according to the experience of Simon Brown, Esq., of the BostonCultivator, (Patent Office Report for 1856), will prove injurious, if placed in the hill in contact with seed, but may be applied broadcast without danger.
TheMenhadenor "White fish", so abundantly caught along our Sound coast during the summer months, or any variety of fish may be composted with muck, so as to make a powerful manure, with avoidance of the excessively disagreeable stench which is produced when these fish are put directly on the land. Messrs. Stephen Hoyt & Sons, of New Canaan, Conn., make this compost on a large scale. I cannot do better than to give entire Mr. Edwin Hoyt's account of their operations, communicated to me several years ago.
"During the present season, (1858,) we have composted about 200,000 white fish with about 700 loads (17,500 bushels) of muck. We vary the proportions somewhat according to the crop the compost is intended for. For rye we apply 20 to 25 loads per acre of a compost made with 4,500 fish, (one load) and with this manuring, no matter how poor the soil, the rye will be as large as a man can cradle. Much of ours we have to reap. For oats we use less fish, as this crop is apt to lodge. For corn, one part fish to ten or twelve muck is about right, while for grass or any top-dressing, the proportion of fish may be increased."
"We find it is best to mix the fish in the summer and not use the compost until the next spring and summer. Yet we are obliged to use in September for our winter rye a great deal of the compost made in July. We usually compost the first arrivals of fish in June for our winter grain; after this pile has stood three or four weeks, it is worked over thoroughly. In this space of time the fish become pretty well decomposed, though they still preserve their form and smell outrageously. As the pile is worked over, a sprinkling of muck or plaster is given to retain any escaping ammonia. At the time of use in September the fish have completely disappeared, bones and fins excepted."
"The effect on the muck is to blacken it and make it more loose and crumbly. As to the results of the use of this compost, we find them in the highest degree satisfactory. We have raised 30 to 35 bushels of rye per acre on land that without it could have yielded 6 or 8 bushels at the utmost. This year we have corn that will give 60 to 70 bushels per acre, that otherwise would yield but 20 to 25 bushels. It makes large potatoes, excellent turnips and carrots."
Fish compost thus prepared, is a uniform mass of fishy but not putrefactive odor, not disagreeable to handle. It retains perfectly all the fertilizing power of the fish. Lands, manured with this compost, will keep in heart and improve: while, as is well known to our coast farmers, the use of fish alone is ruinous in the end, on light soils.
It is obvious thatany other easily decomposing animal matters, as slaughter-house offal, soap boiler's scraps, glue waste, horn shavings, shoddy, castor pummace, cotton seed-meal, etc., etc., may be composted in a similar manner, and that several or all these substances may be made together into one compost.
In case of the composts with yard manure, guano and other animal matters, the alkali,ammonia, formed in the fermentation, greatly promotes chemical change, and it would appear that this substance, on some accounts, excels all others in its efficacy. The other alkaline bodies,potash,sodaandlime, are however scarcely less active in this respect, and being at the same time, of themselves, useful fertilizers, they also may be employed in preparing muck composts.
Potash-lyeandsoda-ashhave been recommended for composting with muck; but, although they are no doubt highly efficacious, they are too costly for extended use.
The other alkaline materials that may be cheaply employed, and are recommended, arewood-ashes, leached and unleached,ashes of peat,shell marl, (consisting of carbonate of lime,)quick lime,gas lime, and what is called "salt and lime mixture."
With regard to the proportions to be used, no very definite rules can be laid down; but we may safely follow those who have had experience in the matter. Thus, to a cord of muck, which is about 100 bushels, may be added, of unleached wood ashes twelve bushels, or of leached wood ashes twenty bushels, or of peat ashes twenty bushels, or of marl, or of gas lime twenty bushels. Ten bushels of quick lime, slaked with water or salt-brine previous to use, is enough for a cord of muck.
Instead of using the above mentioned substances singly, any or all of them may be employed together.
The muck should be as fine and free from lumps as possible, and must be intimately mixed with the other ingredients by shoveling over. The mass is then thrown up into a compact heap, which may be four feet high. When the heap is formed, it is well to pour on as much water as the mass will absorb, (this may be omitted if the muckis already quite moist,) and finally the whole is covered over with a few inches of pure muck, so as to retain moisture and heat. If the heap is put up in the Spring, it may stand undisturbed for one or two months, when it is well to shovel it over and mix it thoroughly. It should then be built up again, covered with fresh muck, and allowed to stand as before until thoroughly decomposed. The time required for this purpose varies with the kind of muck, and the quality of the other material used. The weather and thoroughness of intermixture of the ingredients also materially affect the rapidity of decomposition. In all cases five or six months of summer weather is a sufficient time to fit these composts for application to the soil.
Mr. Stanwood of Colebrook, Conn., says: "I have found a compost made of two bushels of unleached ashes to twenty-five of muck, superior to stable manure as a top-dressing for grass, on a warm, dry soil."
N. Hart, Jr., of West Cornwall, Conn., states: "I have mixed 25 bushels of ashes with the same number of loads of muck, and applied it to ¾ of an acre. The result was far beyond that obtained by applying 300 lbs. best guano to the same piece."
The use of "salt and lime mixture" is so strongly recommended, that a few words may be devoted to its consideration.
When quick-lime is slaked with a brine of common salt (chloride of sodium), there are formed by double decomposition, small portions of caustic soda and chloride of calcium, which dissolve in the liquid. If the solution stand awhile, carbonic acid is absorbed from the air, forming carbonate of soda: but carbonate of soda and chloride of calcium instantly exchange their ingredients, forming insoluble carbonate of lime and reproducing common salt.
When the fresh mixture of quick-lime and salt is incorporated withany porous body, as soil or peat, then, as Graham has shown,unequal diffusionof the caustic soda and chloride of calcium occurs from the point where they are formed, through the moist porous mass, and the result is, that the small portion of caustic soda which diffuses most rapidly, or the carbonate of soda formed by its speedy union with carbonic acid, is removed from contact with the chloride of calcium.
Soda and carbonate of soda are more soluble in water and more strongly alkaline than lime. They, therefore, act on peat more energetically than the latter. It is on account of the formation of soda and carbonate of soda from the lime and salt mixture, that this mixture exerts a more powerful decomposing action than lime alone. Where salt is cheap and wood ashes scarce, the mixture may be employed accordingly to advantage. Of its usefulness we have the testimony of practical men.
Says Mr. F. Holbrook of Vermont, (Patent Office Report for 1856, page 193.) "I had a heap of seventy-five half cords of muck mixed with lime in the proportion of a half cord of muck to a bushel of lime. The muck was drawn to the field when wanted in August. A bushel of salt to six bushels of lime was dissolved in water enough to slake the lime down to a fine dry powder, the lime being slaked no faster than wanted, and spread immediately while warm, over the layers of muck, which were about six inches thick; then a coating of lime and so on, until the heap reached the height of five feet, a convenient width, and length enough to embrace the whole quantity of the muck. In about three weeks a powerful decomposition was apparent, and the heap was nicely overhauled, nothing more being done to it till it was loaded the next Spring for spreading. The compost was spread on the plowed surface of a dry sandy loam at the rate of aboutfifteen cords to the acre, and harrowed in. The land was planted with corn and the crop was more than sixty bushels to the acre."
Other writers assert that they "have decomposed with this mixture, spent tan, saw dust, corn stalks, swamp muck, leaves from the woods, indeed every variety of inert substance, and inmuch shorter time than it could be done by any other means." (Working Farmer, Vol. III. p. 280.)
Some experiments that have a bearing on the efficacy of this compost will be detailed presently.
There is no doubt that the soluble and more active (caustic) forms of alkaline bodies exert a powerful decomposing and solvent action on peat. It is asserted too that thenearly insoluble and less active matters of this kind, also have an effect, though a less complete and rapid one. Thus,carbonate of limein the various forms of chalk, shell marl,[6]old mortar, leached ashes and peat ashes, (for in all these it is the chief and most "alkaline"ingredient,) is recommended to compost with peat. Let us inquire whether carbonate of lime can really exert any noticeable influence in improving the fertilizing quality of peat.
In the case of vitriol peats, carbonate of lime is the cheapest and most appropriate means of destroying the noxious sulphate of protoxide of iron, and correcting their deleterious quality. When carbonate of lime is brought in contact with sulphate of protoxide of iron, the two bodies mutually decompose, with formation of sulphate of lime (gypsum) and carbonate of protoxide of iron. The latter substance absorbs oxygen from the air with the utmost avidity, and passes into the peroxide of iron, which is entirely inert.
The admixture of any earthy matter with peat, will facilitate its decomposition, and make it more active chemically, in so far as it promotes the separation of the particles of the peat from each other, and the consequent access of air. This benefit may well amount to something when we add to peat one-fifth of its bulk of marl or leached ashes, but the question comes up: Do these insoluble mild alkalies exert any direct action? Would not as much soil of any kind be equally efficacious, by promoting to an equal degree the contact of oxygen from the atmosphere?
There are two ways in which carbonate of lime may exert a chemical action on the organic matters of peat. Carbonate of lime, itself, in the forms we have mentioned, is commonly called insoluble in water. It is, however, soluble to a very slight extent; it dissolves, namely, in about 30,000 times its weight of pure water. It is nearly thirty times more soluble in water saturated with carbonic acid; and this solution has distinct alkaline characters. Since the water contained in a heap of peat must be considerably impregnated with carbonic acid, it follows thatwhen carbonate of lime is present, the latter must form a solution, very dilute indeed, but still capable of some direct effect on the organic matters of the peat, when it acts through a long space of time. Again, it is possible that the solution of carbonate of lime in carbonic acid, may act to liberate some ammonia from the soluble portions of the peat, and this ammonia may react on the remainder of the peat to produce the same effects as it does in the case of a compost made with animal matters.
Whether the effects thus theoretically possible, amount to anything practically important, is a question of great interest. It often happens that opinions entertained by practical men, not only by farmers, but by mechanics and artisans as well, are founded on so untrustworthy a basis, are supported by trials so destitute of precision, that their accuracy may well be doubted, and from all the accounts I have met with, it does not seem to have been well established, practically, that composts made with carbonate of lime, are better than the peat and carbonate used separately.
Carbonate of lime (leached ashes, shell marl, etc.), is very well to usein conjunction withpeat, to furnish a substance or substances needful to the growth of plants, and supply the deficiencies of peat as regards composition. Although in the agricultural papers, numerous accounts of the efficacy of such mixtures are given, we do not learn from them whether these bodies exert any such good effect upon the peat itself, as to warrant the trouble of making acompost.
4.—Experiments by the author on the effect of alkaline bodies in developing the fertilizing power of Peat.
During the summer of 1862, the author undertook a series of experiments with a view of ascertaining the effect of various composting materials upon peat.
Two bushels of peat were obtained from a heap that had been weathering for some time on the "Beaver Meadow," near New Haven. This was thoroughly air-dried, then crushed by the hand, and finally rubbed through a moderately fine sieve. In this way, the peat was brought to a perfectly homogeneous condition.
Twelve-quart flower-pots, new from the warehouse, were filled as described below; the trials being made in duplicate:—
Pots 1 and 2 contained each 270 grammes of peat.
Pots 3 and 4 contained each 270 grammes of peat, mixed-with 10 grammes of ashes of young grass.
Pots 5 and 6 contained each 270 grammes of peat, 10 grammes of ashes, and 10 grammes of carbonate of lime.
Pots 7 and 8 contained each 270 grammes of peat, 10 grammes of ashes, and 10 grammes of slaked (hydrate of) lime.
Pots 9 and 10 contained each 270 grammes of peat, 10 grammes of ashes, and 5 grammes of lime, slaked with strong solution of common salt.
Pots 11 and 12 contained each 270 grammes of peat, 10 grammes of ashes, and 3 grammes of Peruvian guano.
In each case the materials were thoroughly mixed together, and so much water was cautiously added as served to wet them thoroughly. Five kernels of dwarf (pop) corn were planted in each pot, the weight of each planting being carefully ascertained.
The pots were disposed in a glazed case within a cold grapery,[7]and were watered when needful with pure water. The seeds sprouted duly, and developed into healthy plants. The plants served thus as tests of thechemical effect of carbonate of lime, of slaked lime, and of salt and lime mixture, on the peat. The guano pots enabled making a comparison with a well-known fertilizer. The plants were allowed to grow until those best developed, enlarged above, not at the expense of the peat, etc., but of their own lower leaves, as shown by the withering of the latter. They were then cut, and, after drying in the air, were weighed with the subjoined results.