MANURES.
Soils, manures, and preparing the soil—plowing, harrowing, &c.—are the three great subjects in any good agricultural work. We shall treat this subject under the following divisions:—
1. The substances of which manures are composed.
2. Preparation and saving of manures.
3. Time and modes of application.
4. The principles of their action upon plants.
Manures are of two classes—called putrescent and fossil. The putrescent are composed of decayed, or decaying, vegetable and animal substances. The fossil are those dug from the earth, as lime, marl, and gypsum. All vegetable substances not useful for other purposes are valuable for manure. Rotten wood, leaves, straw, and all the vegetable parts of stable manure, and any spoiled vegetables or grain, are all valuable. At the South, their immense quantities of cotton-seed are a mine of wealth, if properly prepared and applied as manure. Animal manures consist of the animal parts of stable manure, dry and liquid, parts of bones, brine, spoiled meat, kitchen slops, soapsuds, and all dead animals. In decaying, these substances all pass through a process of fermentation. Left exposed without suitable care, they become unhealthy and offensive. It is probable that a large share of the diseases suffered in the rural districts are caused by these impurities; and the impossibility of keeping large cities free from these substances is the cause of their increased mortality. In the country, a little timely caution and labor, in removing these substances and regulating their fermentation, would save much sickness; while the labor would pay a larger per-cent. profit than any other performed on the soil. No manures should be allowed to ferment, or decay, without being mixed or covered with enough common earth, sand, peat, or muck, to retain all the gases and exhalations of such putrescence. The smallest quantity that will answer is one load of earth to two of the decaying substances. The proportions reversed would be better: put one bushel of lime to two loads, two quarts of ground plaster, and half a bushel of ashes, and you have the very best compost heap. The following are brief general rules for the preparation of manures. It is always most economical to feed cattle in the stable or under cover, and never have manure exposed to the weather. But if cattle must be fed outdoor, let them be fed in a yard, lowest in the centre, that the liquids and washings may run into the centre, and be absorbed by straw and litter. Put manure on the land, or into heaps for compost, before very warm weather. Always feed sheep under cover, and keep their manure from rain; heap it together with earth in the spring, or apply it to the soil at once. Manure thrown out of a stable should be kept under cover, out of the rain, and not allowed to heat in winter; its best qualities are evaporated by fermentation in the yard. Manures often rained on in winter, or left in large piles without intermixture of earth, lime, plaster, and ashes, will ferment and waste. Construct your stables so that the liquid manure will run into a vat filled with earth; muck is best. Experiments have shown that the liquid manures are at least one sixth better than the solid. A gentleman dug a pit, thirty-six feet square and four feet deep, and walled it in on all sides. He filled his vat from a cultivated field, and so constructed his sewers from the stables adjoining that the urine saturated the whole. He kept fourteen head of cattle there for five months, allowing none but the liquid part of the manure to pass into the vat. He spread forty loads of this on an acre. For ten years he tried equal quantities of this and well rotted and prepared stable-manure, side by side, in the same field, and obtained great crops; but in no stage of their growth could he see that crops on the land manured from the stable were any better than those that had received only the soil from the vat. The latter were quite as good as the former. The contents of his vat manured seven acres, or half an acre to each creature stabled. The result is proof that one cow discharges urine sufficient in five months to manure abundantly half an acre of land. Save the solid manure equally well, and a cow will make manure enough, in five or six months, to increase a crop sufficiently to pay for herself. It is certainly safe to say, that a careful man can make the manure of a cow pay for her body every year. Is not this an important branch of farming operations? Few pay sufficient attention to it. Fowls should roost where their droppings may be mixed with common garden soil or loam. The manure from each fowl, carefully saved and judiciously applied, will pay for its body twice a year. The hogstye may be very productive of manure, one fourth better than that from the stable. Connected with your hogpen, have a yard fifteen feet square for every five hogs; let that yard have no floor. Throw the straw out of their sleeping-room frequently to make room for new; throw into the yard, also, all sorts of weeds, refuse vegetables, corn-husks, peapods, &c.; also the dirt that will naturally accumulate in the backyard of a dwelling, including sawdust, fine chips, cleanings of cellars, scrapings of ditches, and occasionally a load of loam, muck, or clay—and six loads of manure to each hog may be made, that will prove far better than any stable manure; it has been known to produce fifty bushels of corn to the acre, when stable-manure produced but forty bushels. Old wood, brush, and chips, should never be allowed to remain on uncultivated, useless land. Wood throws out the same amount of heat in decaying as it does when consumed as fuel. The action of that heat on the soil is highly beneficial, retaining it long in a mellow state: hence, all wood, too old to be of value for any other purpose, should be put in heaps, covered up till decomposed, and then applied to the soil, as other manures. For potatoes or vines, but especially melons, it is preferable to any other manure. Nothing is so good for muskmelons as old chips from the woodyard. Leaves of fruit and forest trees are also very good; blood and offal of animals, hair, hoofs, bones, horns, refuse feathers, woollen rags, mud from sewers, rivers, roads, swamps, or ponds, turf, ashes, old brine, soapsuds, all kinds of fish, oyster and clam shells—all are valuable, and no part of them should ever be thrown away or wasted; they are all good in compost heaps, or applied directly to the soil. Bones are best ground, but may be used whole, pounded, or chemically dissolved, or mixed with alternate layers of fresh horse-manure, they will be decomposed by the fermentation of the manure (see "Bones"). Perhaps there is as much imprudence in wasting manures as in any part of American domestic economy. One who leaves his stock without care, and so exposed to the weather as to lose half of them and injure the others, is not fit to be a farmer; yet, many waste manure that would produce plants for man and beast, of far more value than the loss of stock complained of, and yet no one notices it—it is a matter of course, exciting no surprise. Wastefulness in a family, if it be of bread, flour, or meat, is considered wicked and impoverishing; while ten times that amount may be wasted in manures, that would enrich the soil, and excite little or no disapprobation. We hope the agricultural periodicals will keep this subject before the people, until these mines of wealth will no longer be neglected or wasted.
Application of Manures is a subject that has been much discussed, and respecting which, intelligent agriculturists differ materially. Some apply them extensively as a top-dressing for grass lands. This does much good, but probably one half of their virtues is lost by washing rains, and by evaporation. A better way is not to keep land down in grass long at a time, and, when under the plow, manure thoroughly. We knew a piece of light land that annually produced half a ton of hay per acre. The owner plowed it up, raised a crop, put a moderate quantity of stable-manure, and ten loads of leached ashes to the acre. We saw it in haying time, the third season after it had been manured and subsoiled and seeded down, and they were then taking fully three tons of timothy hay from an acre, which was the quantity it had yielded three years in succession, without any top-dressing. If a top-dressing of manure is to be applied, harrow the land quite thoroughly, and always apply the manure in the fall—it is worth twice as much as when applied in the spring. The rains and snows of winter cause it to sink into the soil, while the heat of spring and summer evaporate it. A mixture of plaster, lime, ashes, and a very little salt, sowed on meadows, immediately after haying, secures a good growth of feed, much sooner than it will come on other meadows. It also increases, quite considerably, the hay crop of the following season. It is a universal rule not to allow manure to lie long on the surface to which it is applied, before plowing in. Place manure in heaps, as large as will be convenient for spreading, and spread it just before the plow. Never spread manure one day to be plowed in the next. When manuring in the hill, have the planters follow the manure-cart. In manuring potatoes in the hill, drop the potatoes, and put the manure on them and cover at once. In a dry season, the yield will be double that of those planted in the usual way. For fall grains, plow in the manure, just before sowing the seed. This is better than plowing it in under the sod. If the land be not sod land, and you can plow the manure in only deep enough to cover it, and then, just before sowing the seed, plow again very deep, the effect is excellent. Apply manure to land in the fall, or just after harvest, and plow it in, let the land remain till spring, and then plow deep, and you get the best possible effect. On an onion crop, manure does the most good on the surface. On those raised from sets, or on any onions, after they get large enough to give room, put fine manure enough to keep down all weeds, and it will double the crop.
Gypsum is better sowed than in any other way. Mixed with a little lime and salt, or wood-ashes and salt, the effect on corn is better than from either alone. To hoed crops apply these articles twice, and always by sowing, and not by putting it around or upon the hills; the effect is much greater sowed, besides the labor that is saved. In applying guano, do not allow it to come in contact with the plants, as it is apt to destroy them.
It only remains to consider the principles on which manure acts upon soils, and produces growth in plants. The action of manure on the soil, by which it is enabled to retain and appropriate moisture, constitutes its main, if not its whole benefit. It may afford a stimulus to the roots of plants. Even the specific manures, that are supposed to supply organic matter to particular plants, may impart their benefits by their action upon the air and water. Facts are certainly at hand to show that the great and leading benefits of manures are in their control of moisture, and where that control is not needed, plants get a great growth on what we call poor soil. No manures, either fossil or putrescent, afford any considerable food for plants. Vegetation receives its growth mainly from water and from the atmosphere. Facts in support of this theory are abundant.
A trial was made to ascertain whence comes the matter of which a tree is composed. A quantity of kiln-dried earth was weighed and then put into a tight vessel. A willow shrub was also weighed and planted in that earth, and the vessel covered with perforated tin to keep out the dust; for a year and a half it was supplied only with pure water. The tree was then taken out, and found, by weight, to have gained one hundred and sixty pounds. The earth was then kiln-dried, as before, and weighed, and its weight was found to be only two ounces less than it was a year and a half before, when it was deposited there. The tree, then, must have received its growth, not from the soil, but from the water or the atmosphere, or both.
Another fact: take a load of manure, dry it thoroughly, and weigh it. Then moisten it and apply it to the soil, and it will increase the weight of vegetation from ten to thirty or forty times its own weight when dry, and yet most of that manure may still be found in the soil. Hence it can only feed plants in a very limited degree. Its action must be on air and water, or the control it gives the soil over those elements.
It is also matter of common observation that soil well manured, will continue moist for a long time after similar land by its side, but which has not been manured, is dried up. Hard coarse soils dry up very quickly, while soft, mellow, and friable ones will endure a long drought. The gases and moisture generated by the decomposition of manures produce this mellow state. Hence the necessity of having that decomposition take place under the soil, or of plowing in the manure.
Another important fact bearing on this question is, that what are regarded very poor soils, such as light sandy or gravelly land, will produce good crops in a season remarkable for the frequency of showers. On such soils crops are from twice to four times as large, in a wet season as in a dry, and yet there is an addition of nothing but moisture, and in such a manner, as not to have it stand and become stagnant among the roots of the plants.
Yet another evidence is in the strength of clay soils. A hard clay is very unproductive. But so disintegrated that plants can grow in it, it produces a great crop. This is because clay is of so close a texture, that when mixed with manure, turf, sand, or muck, although friable, it retains more moisture, than sand or ordinary loam. This is the reason of the superior fertility of land annually overflowed with water, as Egypt in the vicinity of the Nile. It is not that the Nile brings down deposites from the mountains of the Moon, so rich above all that is in the valleys below. The entire weight of all that a river deposites on ten acres would not equal in weight the increased vegetation of a single acre. The cause of the increased fertility is the fact that the deposite is so fine that it prevents rapid evaporation, and thus causes the soil to retain moisture for the large growth, and maturity of the plants.
One more evidence is found on our sandy pine plains. Our common forest-trees, as beech, maple, elm, or linden, will not flourish there. Such land will produce comparatively no corn, oats, or wheat. But rye that stands drought better than any other grain, grows tolerably well. But such plains always produce an enormous growth of pine timber, hardly equalled in the number of cords to the acre, by the heaviest-timbered land of the river bottoms. Why is this? Does a maple need so much more food than a pine, or is it in the habits of the trees? It is not in the richness or poverty of the soil, but in the adaptation of the trees to reach and appropriate moisture. The roots of the maple and beech, spread out near the surface of the ground. And it being a light, porous, sandy soil, it does not retain moisture enough to promote their growth. But whoever notices a pine-tree that has been turned up from the roots by the wind, will see that the roots run down almost perpendicularly ten or fifteen feet into the sand. There they find plenty of moisture and hence their great growth. This principle explains the comparative productiveness of all soils.
A soil composed of light muck, or a kind of peet-soil, will dry up soon. There is nothing to prevent rapid evaporation; hence it is always unproductive, for want of suitable moisture. Mix with it clay, to render its texture more firm, and it will retain the moisture, and be very productive. Clay alone is too solid to retain moisture; it runs off, as from a brick. Mix sand with it, and it becomes mellow, and retains moisture, and produces great growth. Sand allows so free and rapid an evaporation that it is unproductive. We say it leaches and is hungry, and so it is, because it has little power to retain water. Our manures do it good, only as they are calculated to aid it in controlling moisture. If we apply a light manure as we would to clay, it is comparatively useless; it adds no firmness to the texture of the soil, and hence does not increase its capacity for controlling water. On such land, the only good that manure does, is while decomposition is taking place in the soil, it renders it more moist, and hence more productive. Apply clay to such a soil, and it will increase its firmness and consequent capacity of retaining and appropriating moisture, and thus render it highly valuable. Dry straw manure is sometimes said to dry up land, and ruin crops. So of turf in a dry season. In a wet season they greatly increase the growth of crops. Now they contain just as much food for plants in one season as another. Hence a soil too easily impervious to the atmosphere, will be a poor soil, that is, will produce poorly, simply because it has no power to retain the necessary moisture.
We suppose these facts and reasons to establish our theory, that the principal benefit of manures, and of mixing different soils, is in the control they give over the moisture and the atmosphere. Hence the greatly increased crop of clover from the application of three quarters of a bushel of plaster to an acre. The increased weight of clover on five square rods, would outweigh the plaster applied, and still that plaster remains, in almost its full weight, on the soil. This principle explains the benefit of mulching trees, plants, or vegetables. This is the best means of preserving trees, the first year after transplanting, and of securing a great growth, of any kind of shrubs or plants. This may be done with common straw or leaves. Now wherein is their utility? Not in the nourishment they afford the plants, but in the fact that mulching so covers the surface as to prevent rapid evaporation. In such cases, it is the more abundant moisture that secures the greater growth.
Hence the first study of a soil culturist should be to ascertain how he shall so mix and manage the materials at his command, as to cause them to retain moisture for the longest time, without leaving water to stand about the roots of his plants. On this depends the whole importance of deep plowing and ditching. On this theory we may also account for the fact that certain plants prefer a certain kind of manure to all others. It is that those plants act in a certain manner on the soil requiring a specific action of manure to enable it to appropriate moisture and tax the atmosphere for their growth. This theory explains why too much manure is bad. Not because we give too much food to plants, but because excess of manure dries up the land. But whatever theory we adopt, we all agree in the utility of fertilizers. And the experience of practical farmers is of more value in aiding us to reach right conclusions, than all chemical essays on the subject that have ever been written.