GUANO
Should the use of guano induce us to disregard other manures?
Where and in what manner is the best guano deposited?
Guano as a manure has become world renowned. The worn-out tobacco lands of Virginia, and other fields in many parts of the country, which seemed to have yielded to the effect of an ignorant course of cultivation, and to have sunk to their final repose, have in many cases been revived to the production of excellent crops, and have had their value multiplied many fold by the use of guano. Although an excellent manure, it should not cause us to lose sight of those valuable materials which exist on almost every farm. Every ton of guano imported into the United States is an addition to our national wealth, but every ton of stable-manure, or poultry-dung, or night soil evaporated or carried away in rivers, is equally a deduction from our riches. If the imported manure is to really benefit us, we must not allow it to occasion the neglect and consequent loss of our domestic fertilizers.
The Peruvian guano (which is considered the best) is brought from islands near the coast of Peru. The birds which frequent these islands live almost entirely on fish, and drop their excrements here in a climate where rain is almost unknown, and where, from the dryness of the air, there is but little loss sustained by the manure. It is brought to this country in large quantities, and is an excellent fertilizer, superior even to night soil.
How should it be prepared for use?
It should be mixed with an absorbent before being used, unless it is plowed deeply under the soil, as it contains much ammonia which would be lost from evaporation. It would probably also injure plants. The best way to use guano, is in connection with sulphuric acid and bones, as will be described hereafter.
The composition of the various kinds of guano may be found in the section on analysis.
CHAPTER VII
OTHER ORGANIC MANURES
The number of organic manures is almost countless. The most common of these have been described in the previous chapters on the excrements of animals. The more prominent of the remaining ones will now be considered. As a universal rule, it may be stated that all organic matter (every thing which has had vegetable or animal life) is capable of fertilizing plants.
DEAD ANIMALS
What are the chief fertilizing constituents of dead animals?
What becomes of these when exposed to the atmosphere?
How may this be prevented?
The bodies of animals contain much nitrogen, as well as valuable quantities, the phosphates and other inorganic materials required in the growth of plants. On their decay, the nitrogen is resolved into ammonia,28 and the mineral matters become valuable as food for the inorganic parts of plants.
If the decomposition of animal bodies takes place in exposed situations, and without proper precautions, the ammonia escapes into the atmosphere, and much of the mineral portion is leached out by rains. The use of absorbents, such as charcoal-dust, prepared muck, etc., will entirely prevent evaporation, and will in a great measure serve as a protection against leaching.
If a dead horse be cut in pieces and mixed with ten loads of muck, the whole mass will, in a single season, become a most valuable compost. Small animals, such as dogs, cats, etc., may be with advantage buried by the roots of grape-vines or trees.
BONES
Of what do the bones of animals consist?
What is gelatine?
Describe the fertilizing qualities of fish.
The bones of animals contain phosphate of lime and gelatine. The gelatine is a nitrogenous substance, and produces ammonia on its decomposition. This subject will be spoken of more fully under the head of 'phosphate of lime' in the chapter on mineral manures, as the treatment of bones is more directly with reference to the fertilizing value of their inorganic matter.
FISH
In many localities near the sea-shore large quantities of fish are caught and applied to the soil. These make excellent manure. They contain much nitrogen, which renders them strongly ammoniacal on decomposition. Their bones consist of phosphate and carbonate of lime; and, being naturally soft, they decompose in the soil with great facility, and become available to plants. The scales of fish contain valuable quantities of nitrogen, phosphate of lime, etc., all of which are highly useful.
Refuse fishy matters from markets and from the house are well worth saving. These and fish caught for manure may be made into compost with prepared muck, etc.; and, as they putrefy rapidly, they soon become ready for use. They may be added to the compost of stable manure with great advantage.
Should these be applied as a top dressing to the soil?
What are the fertilizing properties of woollen rags?
What is the best way to use them?
Fish (like all other nitrogenous manures) should never be applied as a top dressing, unless previously mixed with a good absorbent of ammonia, but should when used alone be immediately plowed under to considerable depth, to prevent the evaporation—and consequent loss—of their fertilizing gases.
WOOLLEN RAGS, ETC
Woollen rags, hair, waste of woollen factories, etc., contain both nitrogen and phosphate of lime; and, like all other matters containing these ingredients, are excellent manures, but must be used in such a way as to prevent the escape of their fertilizing gases. They decompose slowly, and are therefore considered a lasting manure. Like all lasting manures, however, they are slow in their effects, and the most advantageous way to use them is to compost them with stable manure, or with some other rapidly fermenting substance, which will hasten their decomposition and render them sooner available.
Rags, hair, etc., thus treated, will in a short time be reduced to such a condition that they may be immediately used by plants instead of lying in the soil to be slowly taken up. It is better in all cases to have manures act quickly and give an immediate return for their cost, than to lie for a long time in the soil before their influence is felt.
What is their value compared with that of farm-yard manure?
How should old leather be treated?
Describe the manurial properties of tanners' refuse.
How should they be treated?
Are horn piths, etc. valuable?
A pound of woollen rags is worth, as a manure, twice as much as is paid for good linen shreds for paper making; still, while the latter are always preserved, the former are thrown away, although considered by good judges to be worth forty times as much as barn-yard manure.
Old leather should not be thrown away. It decomposes very slowly, and consequently is of but a little value; but, if put at the roots of young trees, it will in time produce appreciable effects.
Tanners' and curriers' refuse, and all other animal offal, including that of the slaughter-house, is well worth attention, as it contains more or less of those two most important ingredients of manures, nitrogen and phosphate of lime.
It is unnecessary to add that, in common with all other animal manures, these substances must be either composted, or immediately plowed under the soil. Horn piths, and horn shavings, if decomposed in compost, with substances which ferment rapidly, make very good manure, and are worth fully the price charged for them.
ORGANIC MANURES OF VEGETABLE ORIGIN
Muck, the most important of the purely vegetable manures, has been already sufficiently described. It should be particularly borne in mind that, when first taken from the swamp it is often sour, or cold, but that if exposed for a long time to the air, or if well treated with lime, unleached ashes, the lime and salt mixture, or any other alkali, its acids will be neutralized (or overcome), and it becomes a good application to any soil, except peat or other soils already containing large quantities of organic matter. In applying muck to the soil (as has been before stated), it should be made a vehicle for carrying ammoniacal manures.
SPENT TAN BARK
Why is decomposed bark more fertilizing than that of decayed wood?
Spent tan bark, if previously decomposed by the use of the lime and salt mixture, or potash, answers all the purposes of prepared muck, but is more difficult of decomposition.
How may bark be decomposed?
Why should tan bark be composted with an alkali?
Why is it good for mulching?
Is sawdust of any value?
The bark of trees contains a larger proportion of inorganic matter than the wood, and much of this, on the decomposition of the bark, becomes available as manure. The chemical effect on the bark, of using it in the tanning of leather, is such as to render it difficult to be rotted by the ordinary means, but, by the use of the lime and salt mixture it may be reduced to the finest condition, and becomes a most excellent manure. It probably contains small quantities of nitrogen (obtained from the leather), which adds to its value. Unless tan bark be composted with lime, or some other alkali, it may produce injurious effects from the tannic acid which it is liable to contain. Alkaline substances will neutralize this acid, and prevent it from being injurious.
One great benefit resulting from the use of spent tan bark, is due to its power of absorbing moisture from the atmosphere. For this reason it is very valuable for mulching29 young trees and plants when first set out.
SAWDUST
Why is sawdust a good addition to the pig-stye?
What is the peculiarity of sawdust from the beech, etc.?
What is a peculiarity of soot?
Why may soot be used as a top dressing without losing its ammonia?
Sawdust in its natural state is of very little value to the land, but when decomposed, as may be done by the same method as was described for tan bark, it is of some importance, as it contains a large quantity of carbon. Its ash, too, which becomes available, contains soluble inorganic matter, and in this way it acts as a direct manure. So far as concerns the value of the ash, however, the bark is superior to sawdust. Sawdust may be partially rotted by mixing it with strong manure (as hog manure), while it acts as a divisor, and prevents the too rapid action of this when applied to the soil. Some kinds of sawdust, such as that from beech wood, form acetic acid on their decomposition, and these should be treated with, at least, a sufficient quantity of lime to correct the acid.
Soot is a good manure. It contains much carbon, and has, thus far, all of the beneficial effects of charcoal dust. The sulphur, which is one of its constituents, not only serves as food for plants, but, from its odor, is a good protection against some insects. By throwing a handful of soot on a melon vine, or young cabbage plant, it will keep away many insects.
Soot contains some ammonia, and as this is in the form of a sulphate, it is not volatile, and consequently does not evaporate when the soot is applied as a top dressing, which is the almost universal custom.
GREEN CROPS
What plants are most used as green crops?
What office is performed by the roots of green crops?
How do such manures increase the organic matter of soils?
Green crops, to plow under, are in many places largely raised, and are always beneficial. The plants most used for this purpose, in our country, are clover, buckwheat, and peas. These plants have very long roots, which they send deep in the soil, to draw up mineral matter for their support. This mineral matter is deposited in the plant. The leaves and roots receive carbonic acid and ammonia from the air, and from water. In this manner they obtain their carbon. When the crop is turned under the soil, it decomposes, and the carbon, as well as the mineral ingredients obtained from the subsoil, are deposited in the surface soil, and become of use to succeeding crops. The hollow stalks of the buckwheat and pea, serve as tubes, in the soil, for the passage of air, and thus, in heavy soils, give a much needed circulation of atmospheric fertilizers.
What office is performed by the straw of the buckwheat and pea?
What treatment may be substituted for the use of green crops?
Which course should be adopted in high farming?
Why is the use of green crops preferable in ordinary cultivation?
Name some other valuable manures.
Although green crops are of great benefit, and are managed with little labor, there is no doubt but the same results may be more economically produced. A few loads of prepared muck will do more towards increasing the organic matter in the soil, than a very heavy crop of clover, while it would be ready for immediate cultivation, instead of having to lie idle during the year required in the production and decomposition of the green crop. The effect of the roots penetrating the subsoil is, as we have seen, to draw up inorganic matter, to be deposited within reach of the roots of future crops. In the next section we shall show that this end may be much more efficiently attained by the use of the sub-soil plow, which makes a passage for the roots into the subsoil, where they can obtain for themselves what would, in the other case, be brought up for them by the roots of the green crop.
The offices of the hollow straws may be performed by a system of ridging and back furrowing, having previously covered the soil with leaves, or other refuse organic material.
In high farming, where the object of the cultivator is to make a profitable investment of labor, these last named methods will be found most expedient; but, if the farmer have a large quantity of land, and can afford but a limited amount of labor, the raising of green crops, to be plowed under in the fall, will probably be adopted.
Before closing this chapter, it may be well to remark that there are various other fertilizers, such as the ammoniacal liquor of gas-houses, soapers' wastes, bleachers' lye, lees of old oil casks, etc., which we have not space to consider at length, but which are all valuable as additions to the compost heap, or as applications, in a liquid form, to the soil.
What are the advantages arising from burying manure in its green state?
Which is generally preferable, this course, or composting? Why?
In many cases (when heavy manuring is practised), it may be well to apply organic manures to the soil in a green state, turn them under, and allow them to undergo decomposition in the ground. The advantages of this system are, that the heat, resulting from the chemical changes, will hasten the growth of plants, by making the soil warmer; the carbonic acid formed will be presented to the roots instead of escaping into the atmosphere; and if the soil be heavy, the rising of the gases will tend to loosen it, and the leaving vacant of the spaces occupied by the solid matters will, on their being resolved into gases, render the soil of a more porous character. As a general rule, however, in ordinary farming, where the amount of manure applied is only sufficient for the supply of food to the crop, it is undoubtedly better to have it previously decomposed—cooked as it were, for the uses of the plants—as they can then obtain the required amount of nutriment as fast as needed.
ABSORPTION OF MOISTURE
It is often convenient to know the relative power of different manures to absorb moisture from the atmosphere, especially when we wish to manure lands that suffer from drought. The following results are given by C. W. Johnson, in his essay on salt, (pp. 8 and 19). In these experiments the animal manures were employed without any admixture of straw.
[AF] Working Farmer, vol. 1, p. 55.
Muck is a most excellent absorbent of moisture, when thoroughly decomposed.
DISTRIBUTION OF MANURES
The following table from Johnson, on manures, will be found convenient in the distribution of manures.
By its assistance the farmer will know how many loads of manure he requires, dividing each load into a stated number of heaps, and placing them at certain distances. In this manner manure may be applied evenly, and calculation may be made as to the amount, per acre, which a certain quantity will supply.30
Example 1.—Required, the number of loads necessary to manure an acre of ground, dividing each load into six heaps, and placing them at a distance of 4½ yards from each other? The answer by the table is 39¾.
Example 2.—A farmer has a field containing 5½ acres, over which he wishes to spread 82 loads of dung. Now 82 divided by 5½, gives 15 loads per acre; and by referring to the table, it will be seen that the desired object may be accomplished, by making 4 heaps of a load, and placing them 9 yards apart, or by 9 heaps at 6 yards, as may be thought advisable.
CHAPTER VIII
MINERAL MANURES
How many kinds of action have inorganic manures?
What is the first of these? The second? Third? Fourth?
Do all mineral manures possess all of these qualities?
The second class of manures named in the general division of the subject, in the early part of this chapter, comprises those of a mineral character, or inorganic manures.
These manures have four kinds of action when applied to the soil.
1st. They furnish food for the inorganic part of plants.
2d. They prepare matters already in the soil, for assimilation by roots.
3d. They improve the mechanical condition of the soil.
4th. They absorb ammonia.
Some of the mineral manures produce in the soil only one of these effects, and others are efficient in two or all of them.
The principles to be considered in the use of mineral manures are essentially given in the first two sections of this book. It may be well, however, to repeat them briefly in this connection, and to give the reasons why any of these manures are needed, from which we may learn what rules are to be observed in their application.
Relate what you know of the properties of vegetable ashes?
How does this relate to the fertility of the soil?
According to what two rules may we apply mineral manures?
What course would you pursue to raise potatoes on a soil containing a very little phosphoric acid and no potash?
1st. Those which are used as food by plants. It will be recollected that the ash left after burning plants, and which formed a part of their structures, has a certain chemical composition; that is, it consists of alkalies, acids, and neutrals. It was also stated that the ashes of plants of the same kind are always of about the same composition, while the ashes of different kinds of plants may vary materially. Different parts of the same plant too, as we learned, are supplied with different kinds of ash.
For instance, clover, on being burned, leaves an ash containing lime, as one of its principal ingredients, while the ash of potatoes contains more of potash than of any thing else.
In the second section (on soils), we learned that some soils contain every thing necessary to make the ashes of all plants, and in sufficient quantity to supply what is required, while other soils are either entirely deficient in one or more ingredients, or contain so little of them that they are unfertile for certain plants.
Would you manure it in the same way for wheat?
Why?
From this, we see that we may pursue either one of two courses. After we know the exact composition of the soil—which we can learn only from correct analysis—we may manure it with a view either to making it fertile for all kinds of plants or only for one particular plant. For instance, we may find that a soil contains a very little phosphoric acid, and no potash. If we wish to raise potatoes on such a soil, we have only to apply potash (if the soil is good in other particulars), which is largely required by this plant, though it needs but little phosphoric acid; while, if we wish to make it fertile for wheat, and all other plants, we must apply more phosphoric acid as well as potash. As a universal rule, it may be stated that to render a soil fertile for any particular plant, we must supply it (unless it already contains them) with those matters which are necessary to make the ash of that plant; and, if we would render it capable of producing all kinds of plants, it must be furnished with the materials required in the formation of all kinds of vegetable ashes.
It is not absolutely necessary to have the soil analyzed before it can be cultivated with success, but it is the cheapest way.
How is the fertility of the soil to be maintained, if the crops are sold?
What rule is given for general treatment?
Give an instance of matters in the soil that are to be rendered available by mineral manures?
We might proceed from an analysis of the plant required (which will be found in Section V.), and apply to the soil in the form of manure every thing that is necessary for the formation of the ash of that plant. This would give a good crop on any soil that was in the proper mechanical condition, and contained enough organic matter; but a moment's reflection will show that, if the soil contained a large amount of potash, or of phosphate of lime, it would not be necessary to make an application of more of these ingredients—at an expense of perhaps three times the cost of an analysis. It is true that, if the crop is sold, and it is desired to maintain the fertility of the soil, the full amount of the ash must be applied, either before or after the crop is grown; but, in the ordinary use of crops for feeding purposes, a large part of the ash will exist in the excrements of the animals; so that the judicious farmer will be able to manure his land with more economy than if he had to apply to each crop the whole amount and variety required for its ash. The best rule for practical manuring is probably to strengthen the soil in its weaker points, and prevent the stronger ones from becoming weaker. In this way, the soil may be raised to the highest state of fertility, and be fully maintained in its productive powers.
2d. Those manures which render available matter already contained in the soil.
How may silica be developed?
How does lime affect soils containing coarse particles?
How do mineral manures sometimes improve the mechanical texture of the soil?
Silica (or sand), it will be recollected, exists in all soils; but, in its pure state, is not capable of being dissolved, and therefore cannot be used by plants. The alkalies (as has been stated), have the power of combining with this silica, making compounds, which are called silicates. These are readily dissolved by water, and are available in vegetable growth. Now, if a soil is deficient in these soluble silicates, it is well known that grain, etc., grown on it, not being able to obtain the material which gives them strength, will fall down or lodge; but, if such measures be taken, as will render the sand soluble, the straw will be strong and healthy. Alkalies used for this purpose, come under the head of those manures which develope the natural resources of the soil.
Again, much of the mineral matter in the soil is combined within particles, and is therefore out of the reach of roots. Lime, among other thing, has the effect of causing these particles to crumble and expose their constituents to the demand of roots. Therefore, lime has for one of its offices the development of the fertilizing ingredients of the soil.
3d. Those manures which improve the mechanical condition of the soil.
The alkalies, in combining with sand, commence their action on the surfaces of the particles, and roughen them—rust them as it were. This roughening of particles of the soil prevents them from moving among each other as easily as they do when they are smooth, and thus keeps the soil from being compacted by heavy rains, as it is liable to be in its natural condition. In this way, the mechanical texture of the soil is improved.
It has just been said that lime causes the pulverization of the particles of the soil; and thus, by making it finer, improves its mechanical condition.
Some mineral manures, as plaster and salt, have the power of absorbing moisture from the atmosphere; and this is a mechanical improvement to dry soils.
Name some mineral manures which absorb ammonia?
4th. Those mineral manures which have the power of absorbing ammonia.
Plaster, chloride of lime, alumina (clay), etc., are large absorbents of ammonia, whether arising from the fermentation of animal manures or washed down from the atmosphere by rains. The ammonia thus absorbed is of course very important in the vegetation of crops.
Having now explained the reasons why mineral manures are necessary, and the manner in which they produce their effects, we will proceed to examine the various deficiencies of soils and the character of many kinds of this class of fertilizers.