Manures
The use of Manures is to supply nutritive matter for encouraging and sustaining plant growth; any substance, therefore, added to the soil which has the power, either directly or indirectly, of increasing its fertility, may be considered as a Manure. It may contribute directly, by supplying what is requisite, or indirectly, by its action on other substances that might be already present, but not in a suitable state for being absorbed. Growth in plants cannot take place without the main constituent parts of which they are composed being extracted from the earth; and as the production of crops annually necessitates the withdrawal of an enormous supply of certain elements from the soil, it is evident that, were they not restored by some means, exhaustion would, sooner or later, take place. Manures contain, in a concentrated form, the elements requisite for the sustenance of plants, some being much stronger than others, according to the proportion of powerful constituents, combined either in a natural or an artificial manner, in their preparation. The strength of Manures, and their special adaptability for certain crops, must always be a guide to the gardener in disposing of them to the best advantage. In their application to plants at an improper time, or in an improper way, direct harm, or possibly death, may be caused, while the same application, at a suitable season, might be attended with beneficial results. According to experiments which have been made, "all substances entering into the composition of vegetable Manure, or food, must be in a state of fluidity, or in the form of gas or air. The great object, therefore, in the application of Manure, should be to make it afford as much soluble matter as possible to the roots of the plant, and that in a slow and gradual manner, so that it may be entirely consumed in forming its soft and organised parts." Substances of animal or vegetable origin must, therefore, undergo a process of decomposition before they can become absorbed for the nourishment of plants. This may partly take place before they are applied to the soil, or, in some cases, it may be entirely effected afterwards. It is not intended here to describe the nature of different changes which take place chemically, in consequence of the exposure of various substances to the air, or from their being placed in contact with each other. Changes must and do take place naturally; for practical purposes, it matters not so much how they are caused, as how far they succeed in accomplishing their intended purpose in promoting fertility in the soil to which they are applied. All Manures may be, and usually are, divided into two classes. Those composed of vegetable or animal substances of any description are termed Organic; and others, which are of mineral origin, are termed Inorganic.
A few of the different kinds most in use are briefly enumerated below. An excellent plan of applying strong Manures is to mix a proportion with, in many cases, several times its bulk of soil or garden refuse, and so form a fertilising compost, which may be applied to almost any garden crop with excellent results. Composts thus prepared become useful in two ways: the powerful properties of the Manure, when intermixed with soil, become partially absorbed by the latter, and are rendered less harmful; and the decomposition of all the vegetable matter is also at the same time hastened.
I. Organic Manures.
Blood. This is extremely powerful as a Manure. It is rich in nitrogen; but the chemical composition varies somewhat, according to the different animals from which it is obtained. Blood is most safely applied to land after being dried, or when mixed with earthy substances to form a compost.
Bones. Both for field and garden crops, as well as for fruit and other trees, grown in pots or in borders, bones are extensively employed as Manure. When used in merely a crushed state, their decomposition is usually slow, consequently, the fertilising properties are lasting. If reduced to a powder, and applied, the results are observable in a much shorter time. Bones may be dissolved by throwing them into a compact heap, moistening, and then covering them with earth. In this condition, they soon ferment and crumble, and when thus reduced they may be applied to the land. Crushed bones may be advantageously used with nearly an equal amount of ashes, or with one-third their weight of gypsum. Bone Manure is specially beneficial to crops of Turnips.
Farmyard Manure. By this term reference is made to Manure collected from various sources on a farm. The excrements of different animals possess special fertilising properties, and may be kept separate for particular purposes. For ordinary uses, Farmyard Manures are best mixed together, as then a larger number of different constituents are included in the whole, and are consequently available as plant food. The liquid, as well as the solid, portions, should be retained for affording moisture, to cause a slight fermentation, and also for its own enriching properties. Violent heating by fermentation should not be allowed, but partial decomposition of such Manure before adding it to the soil will render the parts more soluble, and in a better state for being readily absorbed. The value of good Farmyard Manure to all crops, and the method of applying it to land is so well known, that no further reference is necessary.
Fish. Fish are sometimes used as Manure. Their decomposition is very rapid, and the quantity applied to land must be limited, on account of its strength. Fish are more safely used as Manure if mixed in a compost of soil and refuse, so that the powerful fertilising properties may be evenly distributed throughout.
Garden Refuse. Such refuse as Cabbage leaves, Turnip tops, and green vegetable matter of almost any description, is valuable as Manure, if dug in when green. If left to decompose first on the surface, many important gases will escape into the air.
Guano. This valuable and well-known Manure, obtained principally from islands off the coast of Peru, and various other places on the coast of South America, is the excrement of sea-birds. It has been deposited there during the course of centuries, and, since being discovered, its exportation has been so extensively practised as to cause uneasiness lest the supply should become exhausted. The quality of Guano obtained from different places varies considerably; that which is supposed to be the best comes from the Chincha Islands, where the supply has, in consequence, been greatly diminished. The chief fertilising properties of Guano having been ascertained by analysis, various artificial manures are now prepared as substitutes, which are very similar in many respects. Pure Guano is far too caustic for use by itself. It should be mixed with about six times its bulk of loamy or charred soil. Thus prepared, it may be used at the rate of about 4cwt. per acre, or, in a small way, as a top-dressing, by spreading thinly and evenly over the surface. For the purpose of watering plants, the proportion of Guano that may be mixed with water varies according to the sort of plant for which it is required. About 1oz. to two gallons of water may generally be used with safety; some plants will, however, bear a stronger solution.
Horn Shavings, &c. The refuse obtained from the parings of horses' feet at the shoeing forge, and also all the shavings &c., made in the manufacture of various articles from horns, are most valuable as Manures. Horn Shavings are readily mixed in any compost, and are most beneficially employed in those prepared for fruit trees, or for any plants which have to be grown in pots. If the particles are not very small, they last a long time without becoming wholly decomposed.
Leaves. These are invaluable as Manure when reduced to a state of mould by a process of gradual decay. They are most beneficially applied to heavy soils and to plants whose roots require somewhat more than ordinary encouragement. Mixed with stable litter, they tend to prevent violent fermentation, and retain, instead, a moderate amount of heat for a much longer period. See also Leaf Mould.
Liquid Manure. Manure of almost any description is quicker in its action, and may be employed most effectually, in a liquid state. It has, also, the advantage that it may be applied at any season when nourishment is required, either by growing crops or plants in pots. Urine is generally too powerful for use by itself as a liquid manure; diluted with water, to the extent of two or three parts of the latter to one of the former, it may usually be safely applied. Water collected from a heap of farmyard Manure, exposed to rain, contains in solution many most important fertilising properties, and is, consequently, very valuable. Cow-dung is readily obtained, and forms one of the best and least harmful of substances for preparing Liquid Manure to be applied to crops or plants of any description. It possesses none of the caustic principles so prevalent in chemical preparations, or, at least, not a sufficient quantity to cause injury when properly used with plants requiring a stimulant. It should be thrown in a large tub, and stirred occasionally, to render the water which is added a dark brown colour. The excrement of sheep, deer, fowls, pigeons; &c., are all of a more concentrated and powerful nature than cow-dung; consequently, they must only be used in more limited quantities. Soot is one of the best substances for Liquid Manure, as it always tends to produce a fine dark colour and healthy foliage. It should be placed in a bag, and left soaking in a tub of water, which may be used most effectually in a clear state. Liquid Manure is frequently made by adding a small portion of some highly concentrated preparation to a can of water, and applying it at once to the plants it is intended to stimulate. This is a ready and a clean method of preparing it, but one which requires some caution in guarding against the dose being too strong. Guano, as previously stated, may be used at the rate of 1oz. to two gallons of water; with many plants a stronger solution will do no harm; but this knowledge must be gained by experience. Sulphate of ammonia may be used in a similar proportion. All chemical Manures intended for use when dissolved in water, should be tried first in a weak solution, and the strength increased gradually if results warrant it. Liquid Manures, being ready for immediate absorption by plants, are most effectually employed when the latter are in an active state, and in want of a stimulant for assisting the development of their crops, or for sustaining their growth. A tank for collecting the drainings from dunghills, or for the special preparation of Liquid Manure, is very useful in or near a kitchen garden, as a supply may always be kept in readiness for use, and the possibility of waste can also be prevented. A slate tank being practically indestructible, is much better than a tub, but one is not always procurable. It might be 6ft. deep, partially sunk into the ground, and provided with a wooden covering, to prevent leaves falling in, and also to preclude the contents from being exposed to view. A perforated partition is sometimes provided, the solid portions of the Manure being kept on one side, and any of the liquid dipped from the other as it is required. A water supply, either in connection with, or in close proximity to, Liquid Manure tanks, is very important where a large quantity is used.
Malt Dust. This forms a very good Manure, and those who have used it speak highly of its qualities. It must be kept as dry as possible, and used in a fresh state. Being quick in action, it proves valuable as a top-dressing to fruit and other trees; but its effects are not of a permanent character when otherwise applied.
Night-soil. An extremely powerful Manure, and one which is rich in nitrogen. Its proper application to crops is generally attended with good results, but Night-soil is not used nearly so much as it might be, partly on account of its offensive odour. This may be effectually taken away by mixing with a deodorizer, such as dry earth, sifted ashes, or, better still, charcoal, or charred peat. Quicklime is frequently recommended, and answers for the purpose; but it, at the same time, dispels a large proportion of ammonia, which is a great loss to the manurial properties. Night-soil should be prepared in a compost for applying to garden crops; mixed with dry earth or charcoal-dust, it may be used lightly as a top-dressing for fruit-trees, especially vines, and for many vigorous-growing trees or plants.
Sea Weeds. In a fresh state, these are frequently used as Manure near the coast, either for digging in the ground or for a top-dressing. The effect on crops is not a lasting one. When burnt, Sea Weeds yield a large proportion of ash, which is peculiarly rich in soda, and consequently valuable as a Manure.
Soot. The fertilising properties of Soot are very valuable. It has an advantage over many other Manures, as it can hardly be misapplied. It should be kept dry until required for use. As a Manure for land, it may be applied at the rate of twenty bushels, or more, to an acre. Soot may be sown with advantage along the drills intended for Turnip, Onion, Carrot, and similar seeds, as, apart from its manurial properties, it materially assists to keep down the larvae of destructive insects.
Woollen Rags or Refuse. In some places, these are used with great success as a fertiliser for Potatoes and all green crops; but, as they are slow in decomposing, the effect produced is extended over a considerable period. The Rags should be chopped up in small pieces, and buried in the soil. II. Inorganic Manures.
Ammonia. One of the chief component parts of Manures, and one which has a powerful stimulating action on the growth of plants. It is formed by the decay of organic matter in the soil, and also in the air; and, being very soluble in water, is rapidly brought to a suitable state for assisting vegetation, by a plentiful supply of nitrogen. Ammonia may be supplied to plants by the application of organic Manures capable of forming it, or by the use of ammoniacal salts. These latter must be cautiously employed, as they are extremely powerful, and their effects are almost immediate. As a dressing for land, they may be applied at the rate of about 2 1/2cwt. per acre, in moist weather, or just before rain, which will quickly carry them into the earth.
Ashes. Wood Ashes, and any small pieces of Charcoal that may be left as the remains of a fire, form excellent Manures, suitable for applying by themselves, or intermixing with others which are of a stronger nature. Wood ashes, being usually rich in potash, are specially valuable to plants requiring this element; but they will not supply the want of organic Manure. Charcoal has the important property of absorbing ammonia and other gases, and again giving them off for the nourishment of plants On this account, it is valuable as a deodorizer. Coal Ashes are valuable as manure in some cases, although inferior to the ashes obtained from wood and vegetables. If they contain many cinders, from not having been thoroughly burned, they are more suited to heavy than to light soils, as they tend to mechanical division, which, though beneficial to the former, may be injurious to the latter. Peat Ashes are also of great benefit. The peat must be thrown out, dried, and then burnt until it becomes charred through, and reduced to cinders. These latter form a valuable dressing for the soil.
Gypsum, or Sulphate of Lime, has been applied with success to crops of Turnips, Potatoes, &c., in quantities of one bushel on sandy, to five or six bushels on clay soil. It acts most beneficially on soils which are naturally dry, or have been made so by artificial drainage. It is not much employed as a Manure in this country.
Lime is a valuable Manure for some soils and plants; but to others its application proves very injurious. See Lime.
Liquor of Ammonia, at the rate of 1oz. to 4 gallons of water, has also a beneficial effect; but, as the strength varies, it should not be applied in larger quantities.
Marls. These are composed of carbonate of lime, mixed with clay, sand, or loam, and frequently with sulphate and phosphate of lime. They are adapted to the improvement of soils which are not already sufficiently charged with lime. Marl is improved by exposure to the sun, and especially to the frosts of winter, before spreading it on the land.
Nitrate of Soda. A powerful Manure, used to a considerable extent, and deemed especially beneficial to grain crops; it is found in large quantities, in beds, and as an incrustation on the soil in some parts of South America. It is imported into this country as a chemical Manure, and also for manufacturing purposes. Its effects are rapid, and very similar to those produced by ammonia.
Salt. On some soils no apparent benefit is derived from the use of Salt. Such lands as are near the sea-coast, and occasionally receive deposits from the salt spray, which is often carried far inland by storms; or such as contain chlorine and soda in any other form, and in sufficient abundance for meeting the requirements of crops, are not affected by it. But in other situations, when used at the rate of five to ten bushels per acre, very material results have followed. Its great affinity for water has the effect of attracting dews and atmospheric vapour to the growing vegetation. Salt is also useful for destroying slugs, worms, and larvae.