Elements of scientific and practical agriculture

Front matter

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Preface

In the following treatise it has been the aim of the author to render the various investigations as simple, natural, and easilyunderstood as possible, and to establish and illustrate them in a plain and familiar manner, without descending to mere puerility. He trusts the methods by which he establishes the processes causing the first soil on the face of the earth, the formation of the secondary rocks, and succeeding formations, and the modes he has employed in explaining the theory and practice of farm cultivation, as well as the causes of the different kinds of soils, etc., will divest those subjects of much of the taystcry that has long enveloped them.

In like manner, using freely what has been done by previous writers, he has endeavored to simplify those elementary prin-- ciples which underlie the Various operations of practical and profitable husbandry.

Much absolute novelty, except in the mode of exposition) cannot now be expected in a work on the Elements of Scientific and Practical Agriculture. Some of the matter, however) the author thinks, is entirely new, while others are for the first time systematically arranged, clearly developed, and fully explained in familiar language.

With regard to the useful application of the science of agriculture to practical farming, there is no difference of opinion among men of sound judgment, and it is only with that subject this elementary work has any concern.

The use of technical terras has been avoided as much as possible. The derivation and meaning of a few words, whicli may not be familiar to all, liave been given at the end of the vi PREFACEl.

book for the convenience of those who may not have a dictionary at hand.

Questions have also been added, which arc merely suggestive, Wlien the work is used for a text-book, the teacher should bo particular to bring out the salient points of each subject, and encourage the pupil to amplify and illustrate his statements in his own words, bearing in mind that the most interesting subject becomes dry and irksome if not thoroughly understood.

It may be assumed as self-evident that agricultural instruction, to be a national benefit, must be accessible to the people, especially the cultivators of the soil. It may also be assumed that this end can be best attained through the public schools, by )neans of a suitable text-book. With this end in View, this work is given to the public. How successful the author has been in supplying the need, the people must judge.

The desire of the author has been to supply a useful, reliable, and compi-ehensive book at as moderate a price aS possible; and he believes lie has given in this work a very large amount of matter in proportion to its size.

Cumberland, Md., February, 1887.

Contents

FIBST DIVISION.

CHAPTER. PAGE.

T. The Chief Object of Agriculture, ... 11

Chapter I. Chief Object Of Agricultural Science

The various operations employed in cultivating the land, so as to make it yield vegetable food abundantly, is called Agriculture. The great object of agriculture is to produce from a given space the greatest quantity of certain kinds of vegetation, with a due regard to the quality of the produce, at the lowest cost, without exhausting the soil.

The sciences of Chemistry, Botany, and Geology are of great value and importance to the cultivator of the soil, as they furnish the means of knowing the different classes of agricultural plants, how they feed, the quantities of the different substances each kind of plant requires, from Avhence they obtain their food, from whence the soil came in which they grow, and how the farmer can best aid the plant in getting an ample supply of food.

We propose to call to our aid only so much of these sciences as may be deemed necessary for the correct understanding of the growth of plants, the tillage of the soil, and the reasons for the practice of intelligent farmers. . . ,

Metaphysics and the fine arts were carefully stiidied by the Greeks and Eomans, in -which they reached a high standard of perfection; but the natural sciences, the offspring of the inductive system, Avere ignored by them.

Until 1820 (Sir Humphrey 'i\i\\) and 1840 (Baron Liebig) agriculture had no scientific basis; it was a mere experimental art. Eflecls were ascertained, but causes were unknown. Happily, chemical analysis and philosophic sagacity at last shed light on the subject. To science we owe most of the comforts of life — ■ such as health, clothing, literature, and locomotion. There is no good reason why the production of our greatest necessity — food — should be excluded from its influence.

Agricultural labor, beyond any doubt, develops man's physique; but it has also been said that it develops the muscles at the expense of the brain. Under the scientific and practical system of farming, no such charge can be maintained; because both brain and muscle are stimulated to activity by the multiplicity of operations, and the varied intellectual inquiries necessary to bring the cultivation of the soil and the growing of crops to a successful issue. Each is thus accorded fair play, and both attain a well developed proportion.

The Bible says: "The sleep of a laboring man is sweet." If the farmer could but realize how greatly blessed he is in this particular, by the character of his labor and surroundings, he would not desire to exchange places wdth the nerve-strained sons of commerce, or the followers of the phantom, Dives — the merchant princes of the cities, or the brokers of Wall street. No one leads a life more in harmony with the divine command given to our first parents than the tiller of. the

SCIENTIFIC AND PilACTICAL AGEICULTUKE. 13

soil; and no one can follow a more peaceful, enjoyable, and healthful pursuit, or has a freer and fuller opportunity for the profitable exercise of intelligence and contemplation of the wonderful goodness of God.

Chapter II. The Growth Of Plants

Plants can only grow when they have a proper supply of the materials they need for building up their various parts; they, like animated beings, require food ; and although in a wild state, they can obtain all the nourishment they require from the air, and from the soil in which they grow; yet, when we produce them in particular places, and in great quantities, for the use of man, we must take great care that they be supplied with food proper for them, and sufficient in quantity. We shall endeavor, in this work, to explain clearly the principles which regulate the supply of food to the plant, and the way by which tlie farmer is able to assist the plant in obtaining it.

The prime object of agriculture, then, is to grow and multiply plants ; therefore, it will be necessary for us to inquire, at the outset, what plants are composed of, and how they grow.

It will be observed that all agricultural plants, such as wheat, clover, beets, potatoes, etc., consist of two principal parts. The root, which is pale colored, growing downward into the soil, and irregularly branched; the stem, or top, which is generally green, grows up into the air, sending out branches in a more regular manner, and produces leaves, flowers, and fruit. Some plants are grown by the farmer for their roots, as turnips; others for their leaves and stems, as cloYer and grass ; and others for their fruit and seeds, as corn, wheat, beans, and peas. The farmer, therefore, talks of root crops, green crops, grain crops, and fruit crops.

Some roots are thick, and grow straight downwards, sending off slender branching fibres, as carrots and beets; others are entirely fibrous, as the grasses. The uses of the roots are to take in nourishment, and fix the l)lant in the soil. Roots are sometimes much longer than the stems. The roots of wheat have been traced to a depth of seven feet, and those of corn have been known to extend a distance of fifteen feet from the stem. The ends of the root-fibers are fine and delicate, and covered with minute hairs, into and through which the nourishment of the plant enters, and finds its way up into the stem.

The stem generally grows upward into the air; but in a few the stem lies on the surface, and in others it runs partly underground. The potato is, in reality, a thickened part of an underground stem, the eyes of which are simply buds. The stem is sometimes hollow, as in wheat, and is always made up of bundles of long cells and vessels, through which water and other substances, taken in from the soil by the roots, pass up into the leaves.

The most important organs connected with the life and growth of all plants are their leaves. A leaf is a thin layer of minute cells spread out to the air, strengthened with ribs or veins, made up of stouter cells or vessels, and covered on both sides with a fine membrane, nearly transparent. In these membranes are minute openings, called pores, through which the plant takes in air and gives off water and gases.

When a plant is full grown, flowers appear upon its branches. Some plants, as the carrot and turnip, take

SCIENTIFIC AKD PEACTICAL AGEICULTUEE. 15

two years to produce their flowers. The first year the root grows thick and fleshy, the tops bearing only leaves. The second year the plant pushes forth a strong stem; it is then said to have "run to seed." The store of nourishment laid up in the fleshy root, during its first year's growth, is consumed in producing the flowering stem, fruit, and seed, after which the root will be found stringy and spongy, and useless for food.

All agricultural plants put forth flowers, but some are very small and dull colored. When the outside of the flower falls off", the middle part grows into fruit, which contains the seed. A grain of wheat is properly a fruit containing one seed; a bean-pod is a fruit containing several seeds.

Chapter III. Seeds And Their Geemination

A SEED contains the young plant and sufBcient nourishment, usually consisting of starch or oil, to support the young plant until it is able to support itself. The embryo consists of a plumule, or young bud, from which the stem will grow up into the air; a radicle, or young root, from which the main root will grow down into the soil; and one and sometimes two seed-leaves, which push up above the soil and become the first green leaves of the plant.

Three things arc necessary to enable a seed to begin to grow: (1) Moisture, which is absorbed by the seed, causing it to enlarge and burst its hard outside case; (2) Warmth, of which some require much more than others in the first stage of germination; and (3) Air, from Avhich tlie seed derives oxygen and carbonic acid gas. When a seed, therefore, is kept moist and warm in the air, it will begin to grow, no matter whether it be placed in the soil or not; but, as it lias to obtain most of its food from the soil as soon as its own store is exhausted, it is best to sow it in the soil at once, being particular to see that it can obtain enough moisture, warmth, and air. The seed then becomes swollen, the young bud enlarges and bursts through the outer skin, the plumule rises into the air, carrying with it the seed-leaf or leaves, or opening out its young green leaves to the sunlight while the radicle descends into the soil, sending off minute branching fibers. The oxygen of the air acts upon the stored-up food in such a way that the oil and starch are converted into a kind of sugar.

That solid substances can be dissolved in water, is difficult for the learner to realize; yet we see instances of it every day in the case of easily dissolved substances, as sugar and salt. A lump of sugar put into a glass of water soon disappears ; still we know it is there, and its presence is easily detected by the taste. Most of the sparkling spring water which we drink has lime, magnesia, iron, and other substances in it; yet it looks clear and bright to the eye. All the substances which constitute the food of plants must be dissolved in water, in this clear and complete manner, before they can be taken up by the rootlets of plants.

SCIEifTIFIC AND PEACTICAL AGEICULTUKE. 17

Chapter IV. Roots Of Plakts And How They Take In Food

If you loosen the earth around and under the root of any young plant, and carefully pull it up, wash off the soil gently in a pan of water, and then examine the root, you will observe it to consist of a number of wMtisll fibers, growing finer and whiter towards the tips. These fibers, put under a strong magnifying glass, will be seen to be hollow tubes, closed at the ends, and having very thin walls. It is through the delicate skin of these hairs on the root-fibers that the plant absorbs the clear water in which its food is dissolved. As the roots grow older and thicker, they lose their hairs, and their outermost layer becomes hard and forms a rind or bark, while the taking in of the water containing the food is carried on by the hairs and cells, upon newer fibers, branching out and spreading v.'ider and deeper into the soil.

In poor soils root-hairs are found to be more abundant than on fibers growing on good soil, because more eff'ort is required to be put forth by the plant in finding food from the thinly distributed nourishment than in good soil, where all the materials required are at hand in abundant supply. But the young student naturally asks : If no openings exist in these hair-fibers, how can the water get in? The following experiment will remove any doubt that may exist on this point: Take a small glass funnel and tie tightly over the mouth of it a piece cf bladder or very thin India rubber, such as is used for children's balloons; now j)Oiir into it some water, in which sugar or salt is dissolved, and dip the covered end into a basin of clean water. After a time it Avill be found that the liquid in the tube has risen, and, on tasting the water in the basin, some of the sugar or salt will be found to have penetrated the membrane. Thus it is proved that fluids, separated ])y a membrane, are able to pass through and diffuse into one another, though there arc no holes to be found in the dividing membrane, even by the most powerful microscope.

Chapter V. What Plants Ake Composed Of

We shall now examine into the composition of plants, and ascertain what becomes of the water and substances, held in solution, which they have drunk up or absorbed. In a green growing plant the most abundant substance is water. Fresh meadow grass contains from seventy-five to eighty-five per cent, of water, while in turnips more than ninety per cent, is found. Therefore, one hundred pounds of fresh grass, when made into hay, will weigh about twenty-five pounds; and, if completely dried in an oven, will weigh only about fifteen pounds.

The water contained in the plant is not stationary, but is passing through the plant, from cell to cell, until it reaches the leaves, where, being spread out to tlie air, it is quickly evaporated through the minute openings, which we before explained as abounding in its covering membrane. A healthy medium sized cabbage has been found to evaporate nearly a pint of Avater in twelve hours; and it lias been calculated that an acre of

SCIENTIFIC AI^D PRACTICAL AGRICULTURll. dS

cabbages -will give out in the course of twelve hours, by evaporation, more than ten tuns of water.

The frame-work of the plant, of which the walls of the cells are made, consists of a substance called cellulose, the most familiar form of which we see in paper or hornets' nests. We may consider, then, the plant to be constructed and built up of an infinite number of minute paper boxes, closed on all sides; and the water, with its contents, oozes through the sides of these boxes, from one to another, till it reaches the leaves; and on its way back from the leaves, each retains that portion of the nutriment which it needed and passes the rest on to its neighbors.

Another very abundant substance is starch. This is in the form of minute grains, stored up in many of the small boxes or cells, which are often packed full of them. A potato consists almost entirely of cells packed and crowded full of starch granules. Starch can be very easily converted into sugar, and in many plants sugar is very plentiful, as in the sweet fruits, sugar cane, in the cells of the beet-root, and sap of the sugar maple. When barley is made into malt, the warmth and moisture cause the starch to be turned into sugar.

Chapter VI. The Organic Compounds

All the substances mentioned in the former chapter, namely, water, Cellulose, starch, sugar, and oil, are found by chemists to be composed of three elements, or simple substances, viz., carbon, oxygen, and hydrogen. Water is composed of oxygen and hydrogen; cellulose, sugar, starch, and oil are each

20 , JILEMENTS OF

composed of carbon, oxygen, and hydrogen, and, in the plant, are often changed from the one to the other.

There are two substances in the phint which must be specially mentioned, and which are made up of four elements, viz., carbon, oxygen, hydrogen, and nitrogen. The first of tliese substances is called protoplasm, a kind of jelly-like material found in all living cells, which, under the microscope, is seen to turn round and round in its cell, and is really the life substance in the plant; and the second is called chlorophyll, or leaf-green, which is formed out of protoplasm by the action of sunlight, and is found in all the green parts of the plant. If a plant is kept from the light it turns yellow and then white. You have all witnessed this in the growths made by potatoes in the cellar, and the blanched stalks of celery, which is caused by earthing them up; because, in the absence of liglit, no leaf-green is formed.

All the substances of the plant which we have been considering, whether formed of three elements or four, are called organic compounds, because they go to make up the principal part of all organized beings — that is, plants and animals having special mem.bers or organs.

Chapter VII. The Ixorganic Substances

If avo take a plant and dry it, and then burn it, all the organic substances disappear and mingle with tlie air, again to be used by otlier plants; and the inorganic, or fixed substances, remain as ashes, which are, in reality, the mineral matters contained in the plant; and these, when analyzed, are found to consist of a number of compounds which are found in many minerals as well as in animals and plants.

The following table shows the materials found in plants:

ORGAKIC. IKORGANIC.

Silica.

Potash.

Soda.

Lime.

Phosphoric Acid.

Carbonic Acid.

Sulphuric Acid.

Magnesia.

Oxide of Iron.

Chlorine.

NOX-NITROGENOUS.

Carbon, Oxygen, Hydrogen only

Starch.

Gum.

Sugar.

Cellulose (or woody fiber' _ Oil.

NITROGENOUS.

Carbon, Oxygen, Hydrogen, and Ni-

Albumen.

Fibrine (gluten), trof'en I Casein (legumen).

Most of these are the common names of substances with which you are familiar.

Potash is so called because it was first obtained by burning plants in a pot, then leaching the ashes and evaporating the water. Iron oxide is the rust seen upon iron when exposed to the air. Silica is the substance which we see in white sand, flint, and quartz-crystals. Ammonia is so called from its having been obtained from the camel-yards near the Temple of Jupiter Ammon, where the worshipers of that idol had congregated for many years; it is also called hartshorn, because of its having been obtained from the horns of the deer. All the inorganic substances named above contain oxygen, except chlorine and ammonia. Chlorine, when liberated from its compound, is a yellow, choking gas, but in the plant it is combined with potash or soda; when combined with the latter, it is called chloride of sodium, known to every person

Note.— Ammonia Is composed of Nitrogen and Hydrogen, and belongs to tbe organic elements.

as common salt. From the strong affinity which clilorinc has for water, if it be set free in a cellar which is damp and mouldy, it Avill destroy the mould and render the cellar sweet and healthful. If an earthen vessel, Avith about two pounds of common salt, be placed in a cellar, and an ounce of sulphuric acid poured over it, the chlorine will be set free from the soda and fill the cellar, Avliich should be tightly shut up for four or five hours. You must be careful not to breathe the gas, and to aerate the cellar thoroughly before entering it. A drink of water is the antidote to the effects caused by inhaling the gas.

The acids named in the table, when found in the plant, are combined with minerals, and are what chemists call phosphates, sulphates, and carbonates. Silica, also, sometimes forms an alliance with minerals, and these compounds are called silicates. We have, therefore, phosphate of potash, phosphate of lime, a very important compound, which constitutes the chief value of bone as a fertilizer; also, we have the sulphate of potash, sulphate of magnesia (epsom salts), sulphate of lime (gypsum and plaster of paris), corbonate of soda, and carbonate of lime (marble and chalk).

Chapter VIII. Plant Food

We may now take up the subject of plant food. All these su])stanccs, found in ]ilants that have grown from very small seeds, must have been obtained by them from without; and, to enable them to grow and be thrifty, they must be in reach of these substances.

As soon as plants have used up the noul-ishment provided for them in the seed, they require a supply of the following organic materials to build up their soft parts, viz. : Oxygen, hydrogen, carbon, and nitrogen; and the inorganic materials, to build up their frame-work or skeleton, viz.: Potash, soda, magnesia, lime, iron, phosphoric acid, sulphuric acid, silica, and chlorine.

Full-sized, healthy plants have been grown to complete maturity, without any soil at all, by suspending them, with their roots dipping, into avessel of water in which has been dissolved a supply of all these articles of plant food. Some exceedingly interesting experiments have been made in growing plants artificially, with food specially prepared and dissolved in water. Some may be desirous of trying the experiment, and, as it will be instructive as well as interesting, we shall describe in the next chapter one of the best modes of procedure, which has been successfully tested.

It is of great importance to keep in mind the sources from which plants derive their food:

First — Air. The air is mainly composed of two gases, nitrogen and oxygen, with a small portion of carbonic acid gas, which is itself a compound of oxygen and carbon, and still smaller quantities of ammonia and nitric acid; the former of which contains nitrogen and hydrogen, and the latter nitrogen and oxygen. Careful experiment has shown that none of the free nitrogen of the air is taken in by plants, and that, small as the carbonic acid is in the air, it is the source of almost all the carbon found in plants. The leaves absorb carbonic acid from the air, and then, under the influence of sunlight upon the Icaf-grcen, the carbonic acid is separated into its elements (carbon and oxygen); the

2i ELEMENTS OF

carbon i^ retained by the i)l;uit, which uses it in forming cellulose, starch, sugar, and otlier substances; Avhile the oxygen is given out to the air.

Oxygen is also, at times, absorbed from the air, esi^ecially when the jjlants are growing rapidly and coming into flower. The ammonia and nitric acid are washed down into the soil by the rains, and then taken in by the roots, supplying the plants with a small portion of nitrogen.

Second — Water. Pure water is a combination of oxygen and hydrogen. When water is used by the plant, its duty is chiefly to convey other matters, Avhich it holds in solution, to the root; but some of it is divided up and used by the plant in forming the starch and other organic matters. Rain water is the purest natural water known, having nothing dissolved in it but what it has washed down out of the air; but, as soon as it enters the soil, it begins to dissolve the mineral matters there, and carries them to the roots of plants.

Third — The soil. We have now seen what plants obtain from air and water; the rest of the nitrogen, and all the mineral or inorganic substances, must be obtained from the soil and brought to the roots clearly and completely dissolved in water.

Chapter IX. Experiment With Water Culture Of Plants

In order to make the experiment of growing a plant to perfect maturity, without being planted in the soil, take a wide-mouthed bottle, capable of holding one or two quarts. It must be fitted with a cork, and a hole

6CIEKTIFI0 AND PRACTICAL AGRICULTURE. 25

made in the centre of the cork, say half an inch in diameter, and an opening cut from it to the circumference, 60 tliat the phmt may be glided out and in easily when required. You will next cover the bottle with stout paper, and top or neck with black sealing wax. It is a most important matter that darkness be secured, for plants feed through the roots best in the dark, as well as to prevent any fungoid growth within the dining-room of the plant.

We have next to see to the preparation of the bill of fare, and there are many of such bills. We shall select the following one, as suitable for the purpose, which has been successfully used by a celebrated English chemist:

Take finely powdered burnt bone (three hundred grains), put in a glass flask with Avater (pint), and to it nitric acid is cautiously added, so as to dissolve the bone, the flask being heated. After this has been done, a solution of carbonate of potash is added to the hot liquor, until it becomes slightly turbid. This represents the only troublesome portion of the cooking arrangements, for it now only needs the three following bodies to be added*. Nitrate of potash, one hundred a-nd seventy grains; crystallized sulphate of magnesia, one hundred and seven grains; and chloride of potassium, forty-six grains, with water suflicient to make it up to a quart.

We have thus prepared a very large supply of plant food; for although in its concentrated condition it only represents a quart, yet it will really give about ten gallons when properly diluted. When we are going to use the food for..plants, we take about two tablespoonsful, and add it to a quart of distilled water, and mix in with it one drop of a strong solution of perchloride of iron. This weak and delicate liquid now represents a very valuable plant food, and in this condition it is ready for use.

The seed having been sprouted in sand, the young plant is washed and then suspended in the hole of the cork, by the aid of cotton, wool, or other similar soft substance, with its roots reaching down to ilio water and its leaf in the air. Until a green leaf appears, clean water is supplied; but on the appearance of the green leaf, the cork and plant are removed from the bottle, the water is poured away, and the bottle filled with the properly diluted food.

When the growth of the plant is slow, there need not be any fresh supply of food for fully fourteen days; but in hot weather, when the growth is active, it is necessary to give fresh supplies every seven days. On these occasions the bottle is emptied and an entirely fresh supply of the diluted food is given. In this way you will produce a perfect plant without putting it into the soil.

The experiments which have been carried out go far to prove that plants take their supplies in a very dilute form, and yet these homeopathic quantities are really necessary. Take, for example, the one drop of iron solution added to a quart of water, being a ratio of about one to twenty thousand, and yet this minute supply was absolutely necessary. It was discovered by the same chemist that, when this iron was omitted, the young plant became yellow and sickly; but it quickly became green, and assumed a luxuriant growth, when this minute quantity of iron solution was added.

In the preparation of these watery solutions it is necessary to use distilled v.ater if we want to arrive at accurate conclusions, because all natural supplies of water hold in solution more or less of the materials which plants require for food.

SCIENTIFIC AND PRACTICAL AGRICULTUEE. 27

Chapter X. How Plants Feed

Spring waters are sometimes sufficiently charged with the substances tliey have dissolyed in their passage among rocks an'd soils, so as to be capable of maintaining the growth of plants. Eain-water is also more or less impregnated with matters taken from the air as it falls, so that it cannot be considered perfectly pure.

The lesson we may learn from these facts are, that plants take in their mineral food in an exceedingly dilute condition and in a beautifully bright form; likewise we learn that if they do not receive all the materials they require, they soon show that they have some want by presenting a sickly appearance, which will, ere long, result in a cessation of growth, and ultimately in untimely death.