experiments of Dr. Voelcker, made upon large quantities of manure, treated in various manners, for the purpose of noting results from careful analyses from time to time are interesting. It was shown that the great loss occurring to barn yard manure in the process of rotting is not the escape of ammonia into the air, for it was found that this was light, but the principal loss is in the washing out of the soluble portions by the rain. In the climate of England where evapora tion is slow, and rain falls often, this would take place to a greater extent than here, since we must use means to keep it moist enough during summer while in England, they have to guard against leaching. The idea is to keep the whole mass moist, but not dripping. The following table gives tlie composition in pounds of an exper imental heap of manure at four different periods, showing the changes that occurred: It is to be observed that during the first six rnonths, although the weight of the manure largely diminished, the loss was almost exelu .ively confined to the insoluble organic roatters ; while soluble matters had increased, and the ammonia remained undiminished. But durin the hot summer weather all the most valuabre matters had undergone diminution. The con clusions to which they lead are these: Farm-yard manure, in its fresh state, contains but a small quantity of ammonia, most of its nitrogen being there as insoluble nitrogenous matters. But as the decomposition advances the ammonia increases, and a quantity of organic matter becomes soluble. For this reason the manure should be preserved in such a manner as to pre vent the escape of the soluble portions which are the most valuable. This can be effected by keeping it in water tight pits, or under cover; but in the latter case the manure, particularly if it contain a large proportion of litter, is not sufficiently moist to admit of its ready fermen tation, and water must be added in sufficient quantity to promote that change. The worst of all modes of keeping manure is to pile it in heaps in the corners of the fields, for under such cir cumstances it is most liable to loss; and if the manure must be carted out, it is better to spread it upon the soil at once, because when this is done fermentation is stopped; and as there is very little free ammonia the loss is small, and the soluble matters are uniformly washed iuto the soil by the rain. Dr Voelcker is of opinion that the most advantageous mode of applying the manure would be in all cases to leave it on the surface to be washed into the soil, by which means its distribution is more uniform than if it be plowed in. The most disadvantageous mode of making manure is to produce it by cattle in open yards, for in this way at least two-tbirds of the valuable matters are lost after a year's exposure. Liquid manures are the soluble portions of any substance containing plant food in combination witb water. Thus, the drainings of the barn yard into any depression that becomes puddled so as to retain water, is liquid manure, but the proper way to obtain it is to prepare a tank into which it may leach without waste. Dr.Voelcker, made extensive experiments on the changes which liquid manure undergoes in soils of known composition. The following were the conclusions arrived at : Liquid manure, in contact with soil, undergoes a num ber of chemical changes.
These changes are greater in tbe case of clay and cal careous soils, than in the case of sandy soils.
Passed through clay, and calcareous soils, liquid manure leaves a considerable quantity of ammonia in the soil.
Under the same circumstances, liquid manure parts likewise w tilt potash and phosphoric acid.
Sandy soils remove from liquid manure but little am monia, and likewise not much potash.
With the exception of purely sandy soils, liquid manure, as used in practice, leaves the greater portion of all the most valuable fertilizing matters in the generality of soils. The comparative power of different soils to remove ammonia, potash, and phosphoric acid from liquid ma nure, differs greatly.
Liquid manure passed through sandy soils rich in sol uble silica takes up soluble silica.
Soils that absorbed much ammonia also absorbed much potash, and the soils which absorbed little ammonia also absorbed little potash.
Soda salts (common salt) are either not at all removed by liquid menu, e, or only to a small extent.
Chloiine, and generally sulphuric acid, remain unal tered in quantity in liquid manure passed through dif ferent soils.
In most cases liquid manure left in contact with different soils becomes richer in lime.
The proportion of lime which liquid manure takes up from the soils with which it is brought in contact does not altogether correspond with the relative proportions of lime in the different soils.
Liquid manure passed through a sandy soil greatly defictent in lime became poorer in lime; thus showing that the property of soils, of storing up food for plants, is not confined to ammonia, potash, or phosphoric acid, but that it is a property which manifests itself in a variety of ways. Thus suits rich in lime yield this substance to liquid manure. Again, potash usually is remo, ed from liquid manure left in contact with soils; but in particnlar Lases liquid manure may even become richer in potash after filtration through soil.
Very soluble saline fertilizing compqnnds are probably injurious to vegetation when supplied too abundantly to the land.
All moderately fertile soils have the power of rendering the more important soluble fertilizing matters much less soluble; but in none of the experiments were ammonia, potash, phosphoric acid and otber compounds that enter into the composition of the ashes of our cnitivated crops, rendered perfectly insoluble.
It does not appear probable that plants take np mineral food from the soil in the shape of totally insoluble com binations.
In surface manuring, not always practicable, but when so, always effective and economical, since fresh manure may be used, as in the case of fallows, meadows, pastures, orchards, etc., we save the elements of strength in the manure and really get the benefits of liquid manuring. In relation to this matter, Mr. Bright, a well known horticulturist, and writing on manuring from a horticultural stand point, says: The practice of top-dressing, or of surface-manuring, has long been the favorite method employed by all intelligent gardeners within the circle of my acquaintance. We have long ago learned that masses of rich, nitrogenous manures are not what plants require about their roots, hut that manures are applied much more successfully (and less injuriously) by top-dressing, either in solid or liquid form. Nature never manures her plants with crude masses of concentrated fer tilizing substances, but imparts her stimulating and mineral food in a state of the most minute division—almost infinitesimal—chiefly from the surface of the earth. No wonder so many fruit trees have been killed, so many grape vines destroyed or rendered barren by excess of wood, in consequence of the heavy manuring at the roots so universally recommended by writers on gardening and horticulture. The great objec tion to surface-manuring is founded upon the probable loss of ammonia, caused by the expo sure of decaying manures upon the surface of the earth. But this loss has been shown, by sound reasoning, and by facts deduced from practical experience, to he much less than is commonly apprehended ; while the benefits aris ing from surface-manuring in other respects, more than counterbalance any p ssible loss of ammonia from this practice. In the first place, when manures are exposed upon the surface of the earth, even in hot weather, decomposition no longer goes on so rapidly as when the same manures are kept in a; heap, and the ammonia that is produced is gradually carried into the soil by rains. The other soluble substances, as potash, lime, the phosphates, etc., are of course not lost, because they are not volatile. Nor are these soluble and valuable substances lost to plants by being carried into the soil before they are needed by growing plants. It has been con clusively shown by eminent scientific authorities that any good soil. containing a fair proportion of clay and carbon, is capable of taking up and retaining effectually ammonia„ lime, potash, soda, etc., in a soluble form, so that little, if any, passes off in the under-drainage water of such soils. These substances, it is true, may wash from the surface, hut they can not pass through a good soil and go off in the drainage water. By surface-manuring we mulch the ground, and render it cooler in summer and warmer in winter. More shade is an important element in culture—so important that some writers have thought shade alone to be equiva lent to manure. A piece of soil heavily shaded by surface-manuring actually decomposes like a manure heap--that is, it undergoes a sort of putrefaction or chemical change, which sets free its chemical constituents, unlocks, as it were, its locked-up manurial treasures, and fits its natural elements to become the food of plants. Darkness, moisture and air are the con ditions required for veaetable and mineral de composition, for under bthese conditions decay is quick. These conditions are produced in the soil by surface-manuring. Then, again,when the surface-manure decomposes, its elements are washed into the soil in a state of solution pre cisely fitted to meet the wants of plants, and they become active agents in promoting further decomposition and chemical changes in the body of the soil. Manure, then, chiefly upon the sur face. Do not waste your manures by mixing them deeply with the soil. Plant shallow. Keep roots of all trees, plants, and vines as near .the surface as possible. There are weighty reasons for the position assumed in preceding sentence, says our authority, and he reiterates most forcibly, plant then shallow. Let your
soil be deep and dry, but plant near the surface as much as possible. Top-dress your gTass, after mowing in July or August, under a burningsum mer sun ; top-dress in the fall, before and during the autumn rains ; manure the surface while snow is on the ground, while the March winds blow, and while the April rains fall. Manure your grass, instead of your corn and wheat, broadcast at any time when you have manure and leisure, and you will be abundantly satisfied with the result. In the application of farm-yard manures, criti cally carried.out in the United States, there have been but comparatively few well digested exper iments. In Europe the case is different. There they have experimented largely and with barn yard and commercial manures. The Superin tendent of the Kansas Agricultural College farm made the following experiment, to determine the value of green manure both, as against yield on poor land with manure and as against yield upon naturally rich soil, and also, as between manure and no manure on homogeneous and fer tile soil with the following results, illustrating its decisive value even on the more fertile of western soils: One half of field No. 7 of the Kan sas State Agricultural College farm is a badly washed hill-side, washed to the underlying red and yellow clay. The other half of the field is second bottom; the soil a deep alluvium, rich and black. A sharper contrast in one field could hardly be imagined. This contrast furnished an, opportunity for testing the relative merits of manure, an opportunity that was gladly im proved. Early in May the clay hill-side was dressed with green stable manure, at about the rate of thirty tons per acre, which was immedi ately plowed under to the depth of five or six inches, the nature of the soil not permitting a deeper furrow. Even at this shallow depth. the soil rolled up after the plow in hard, sticky masses, upon which harrow and roller had but little effect. Many who saw the field at this time expressed the opinion that the hill-side would not produce even corn nubbins. After plowing, the clay hill-side was top-dressed with a compost of rotted manure, ashes, and old mor tar, at the rate of fifteen two-horse loads per acre, after which the whole surface was repeat edly harrowed and rolled. As soon as this was finished the whole field, the lower half having been plowed to the depth of eight inches and thoroughly harrowed in the mean time, was, marked off and planted with corn, the Milton or Mammoth Dent. No manure was used upon the lower part of the field. Both parts were cultivated alike. The land was new, this being the second crop from the sod. The crap was harvested the last of Novemher, and returned forty-five bushels per acre from the lower land and sixty-five bushels per acre from the manured clay hill-side, an advance of forty-five per centum in favor of the washed hill-side, and attributable alone to the effect of the manure. In the earlier part of the season this field was frequently trespassed upon by cattle, and prob ably one-third of the crop was thus deStroyed. As. the two parts of the field suffered alike, the result pro rata is the same, and we have in contrast the poorest and best of our Kansas soils. The poorer, treated with manure at the cost of $11 per acre, exceeding by forty-five per centum the yield of the better soil without manure. It would be difficult to more strongly illustrate the effect- of home-made fertilizers upon Kansas clays. The contrast in this single instance, however, may be too well defined for general application. Fields Nos. 5 and 6 of the Col lege farm present no such contrast, being iden tical in soil and situation, the division being entirely arbitrary, and only indicated by a narrow drive. These two fields are a fair representation of prairie loam, conforming essentially to the soil of the second bottom of field No. 7. Field No. 5 received an application of green stable-manure, at the rate of forty,tons per acre. No. 6 received no manure. Cultivation essen tially the same. Result: the yield of sound corn upon field No. 5 was 100.1 bushels per acre, as ascertained by actual measurement by a commit tee of disinterested persons. The return from No. 6 was between sixty and sixty-five bushels per acre, or an increase of fifty-eight and one third to sixty-six and two-thirds per centum per acre, due solely to the use of manure. At the Michigan Agricultural College the follow ing results were obtained : One acre of very light sandy soil was Selected from a clover field, the second year from seeding and mowed once in 1867. This acre was equally divided into sixteen plots, and manures were applied to every alter nate plot, as follows: The two composts of muck and ashes, and the two of muck and lime, having been carefully mixed, under shelter, in February 1868, and shoveled over from time to time, till properly incorporated. On plot 1, one load of muck and leached ashes, mixed in the propor tion of five loads of muck to two loads of ashes; on plot 3, one load of muck mixed with quick lime slaked with water, in the proportion of five loads of muck to ten bushels of lime ; on plot 5, one load of muck and quicklime slaked with a saturated solution of common salt, in the propor tion of five loads of muck to ten bushels of lime ; on plot 7, one load of muck and wood ashes, in the proportion of five loads of muck to one load of ashes; on plot 9, one load of muck; on plot 11, one-half bushel of ashes and one-eighth bushel of gypsum; on plot 13, one-half bushel of ashes ; on plot 15, one-eighth bushel of gypsum. The following table exhibits results in pounds: According to this exhibit, the total products of the unmanured plots, respectively considered, ranged from one and one-sixth ton to two and one-seventh tons of hay, reckoning 2,240 pounds to the ton. It will be seen. by reference to the widely-ranging products of the unmanured plots, that the soil was, in the first place, quite unequal in productiveness. Caution. is, therefore, required in drawing conclusions from these results. The statement of gain arising from each applied manure is estimated by comparison with the yield of adjoining unmanured plots. The prom inent points of the exhibit are these: The muck and leached ashes, the gypsum, and the muck and wood ashes gave the largest products; the ashes and gypsum were less effective than the gypsum alone; a loss resulted from the applied mixture of muck and lime slaked with brine. The following results will be interesting as show ing experiments in England with manures of various kinds, both domestic and commercial: The first is a selection from a report of experi ments made by _Messrs. H. F. and A. Harwood, of Ipswich, England, in 1872, on light land which had been cropped in 1870 with wheat, manured with ten tons of farm-yard dung per acre, aud in 1871 with barley, maimed with rive cwt. of mixed artificial manures per acre. This barley crop having been removed, equal plots were nteasured off, various manures applied, at a cost of €3 10s, per acre, in each ease, and wheat sown. Other plots were marked off for barley. The table. on page 627 gives the descriptions of manures and the quantities applied per acre, and the results obtained. The superphosphate received by wheat plots 14 and 15 contained, respeetively, twenty-eight per cent. and seven teen per cent. of soluble phosphates. In addi tion to the merchantable grain represented in the column of yield, there was a small amount of refuse grain, the value of which is ineluded in the statements of total values of the crops. Applications of this exhibit to American practice will, of course, be modified by prices of manures and values of grain and straw in different loealities. English experimentalists have found that in gen eral not one-half of the nitrogen of such manures as guano, ammonia. salts, and nitrate of soda, is recovered in the increase of the crop to which they are applied. As to the residue, a portion may remain comparatively inactive in the soil, and a considerable .portion may, under condi tions favorable to drainage, be carried away and lost. With a view to these points, experiments were commenced at Rothamsted, England, in 1871, to determine whether any economical advantage can be gained by applying such manures in comparatively small quantities near the seed, instead of larger amounts broadcast and harrowed in. In the following tabulated experiment with wheat, the plots measured one quarter of an acre each, and the amount of seed in each case was one bushel per acre. The fertilizers in this and the barley experiment were intimately mixed with ashes of burned clay before applica tion. The 146 pounds sulphate of ammonia applied on plot two contained nitrogen equal to that contained in tif teen bushels of wheat, With straw in proportion, and the imperfect recovery of the nitrogen is indicated by the fact that the yield on this plot was only seven and three fourths bushels per acre in excess of that of the unmanured plot. That the soil can not he ex pected to return any large additional percentage of the nitrogen in seasons subsequent to that of the application has been already shown by experiments at Rothamsted. In his report for 1864, Mr. Lawes says that the unexhausted residue of nitrogen supplied in ammonia salts was but very partially and very slowly recovered in increase of crop in succeeding years, even with liberal applications of such mineral manures as were very effective to crops when used in conjunction with newly applied ammonia salts. The subjoined is a tabulation of experiments on barley. The plots were one-half of an acre each; amount of seed, three bushels per acre, except on plot five, which received one and a half bush els of seed per acre.