103

103

106

GENERAL

ESSAY

ON

CALCAREOUS MANURES.

CHAPTER I.

PART I-Theory.

DESCRIPTION OF EARTHS AND

SOILS.

slowly imbibing the water, are distended enough to fill the space occupied before.

Calcareous earth, or carbonate of lime,* is lime combined with carbonic acid, and may be converted into pure or quick-lime by heat-and quickIt is very necessary that we should correctly lime, by exposure to the air, soon returns to its distinguish earths and soils and their many varie- former state of calcareous earth. It forms marble, ties: yet these terms are continually misapplied-limestone, chalk, and shells, with very small adand even among authors of high authority, no mixtures of other substances. Thus the term two agree in their definitions, or modes of classifi- calcareous earth will not be used here to include cation. Where such differences exist, and no one either lime in its pure state, or any of the numerknown method is so free from material imperfec-ous combinations which lime forms with the vations, as to be referred to as a common standard, it rious acids, except that one (carbonate of lime) becomes necessary for every one who treats of which is beyond comparison the most abundant soils, to define for himself-though perhaps he is throughout the world, and most important as an thereby adding to the general mass of confusion ingredient of soils. Pure lime attracts all acids so already existing. This necessity must be my powerfully, that it is never presented by nature exapology for whatever is new or unauthorized in cept in combination with some one of them, and the following definitions.

generally with the carbonic acid. When this The earths important to agriculture, and which compound is thrown into any stronger acid, as form nearly the whole of the known globe, are muriatic, nitric, or even strong vinegar-the lime only three-silicious aluminous, and calcareous. being more powerfully attracted, unites with, and Silicious earths, in its state of absolute purity, is dissolved by the stronger acid, and lets go the forms rock crystal. The whitest and purest sand carbonic, which escapes, with effervescence, in the may be considered as silicious earth in agriculture, form of air. In this manner, the carbonate of though none is presented by nature entirely free lime, or calcareous earth, may not only be easily from other ingredients. It is composed of very distinguished from silicious, and aluminous earth, hard particles, not soluble in any common acid, but also from all other combinations of lime. [See and which cannot be made coherent by mixing Appendix A.†} with water. Any degree of coherence, or any shade of color that sand may exhibit, is owing to *Carbonate of lime is the chemical name for the the presence of other substances. The solidity of with lime. The names of all the thousands of different substance formed by the combination of carbonic acid the particles of sand renders them impenetrable to substances (neutral salts) which are formed by the water, which passes between them as through a combination of each of the many acids with each of sieve. The hardness of its particles, and their the various earths, alkalis, and metals, are formed by loose arrangement, make sand incapable of ab- one uniform rule, which is as simple and easy to be unsorbing moisture from the atmosphere, or of re-derstood and remembered, as it is useful. To avoid taining any valuable vapor or fluid, with which it repeated explanations in the course of this essay, the may have been in any manner supplied. Silicious rule will now be stated by which these compounds are earth is also quickly heated by the sun, which named. The termination of the name of the acid is adds to the rapidity with which it loses moisture. changed to the syllable ate, and then prefixed to the Aluminous or argillaceous earth, when dry, ad- particular earth, alkali, or metal with which the acid is united. With this explanation, any reader can at once heres to the tongue, absorbs water rapidly and understand what is meant by each of some thousands abundantly, and when wet, forms a tough paste, of terms, none of which might have been heard of besmooth and soapy to the touch. By burning it fore, and which (without this manner of being named) becomes as hard as stone. Clays derive their ad- would be too numerous to be fixed in the most retenhesiveness from their proportion of aluminous tive memory. Thus, it will be readily understood earth. This also is white when pure, but is gene- that the carbonate of magnesia is a compound of the rally colored deeply and variously-red, yellow, or carbonic acid and magnesia-the sulphate of lime, a blue-by metallic substances. When drying, compound of sulphuric acid and lime-the sulphate of iron, a compound of sulphuric acid and iron-and in aluminous earth shrinks greatly-it becomes a like manner for all other terms so formed. mass of very hard lumps, of various sizes, sepa- The note referred to in the appendix A, will suprated by cracks and fissures, which become so ply some remarks and explanations which a scientific many little reservoirs of standing water, when reader would correctly consider as a deficiency if enfilled by rains, and remain so, until the lumps, by tirely omitted, but which, if added to the text above,

Calcareous earth in its different forms has been supposed to compose as much as one-eighth part of the crust of the globe. Very extensive plains in France and England are of chalk, pure enough to be nearly barren, and to prove that pure calcareous earth would be entirely so. No chalk is to be found in our country-and it is only from European authors that we can know any thing of its agricultural characters, when nearly pure, or when forming a very large proportion of the surface of the land. The whiteness of chalk repels the rays of the sun, while its loose particles permit water to pass through, as easily as sand:† and thus calcareous earth is remarkable for possessing some of the worst qualities of both the other earths, and which it serves to cure in them (as will hereafter be shown) when used as a manure.

Most of those who have applied chemistry to agriculture, consider magnesia as one of the important earths. Magnesia, like lime, is never found pure, but always combined with some acid, and its most general form is the carbonate of magnesia. But even in this, its usual and natural state, it exists in such very small quantities in soils, and is found so rarely, that its name seems a useless addition to the list of the earths of agriculture. For all practical purposes, gypsum (though only another combination of lime,) would more properly be arranged as a distinct earth, or element of soils, as it is found in far greater abundance and purity, and certainly affects some soils and plants in a far more important manner than has yet been attributed to magnesia, in its natural form.

All the earths, when as pure as they are ever furnished by nature, are entirely barren, as might be inferred from the description of their qualities: nor would any addition of putrescent manures§ enable either of the earths to support healthy vegetable life.

some one valuable crop-as some plants require a degree of closeness, and others of openness in the soil, which would cause other plants to decline or perish.

Soil seldom extends more than a few inches beiow the surface, as on the surface only are received those natural supplies of vegetable and animal matters, which are necessary to constitute soil. Valleys subject to inundation have soils brought from higher lands, and deposited by the water, and therefore are of much greater depth. Below the soil is the subsoil, which is also a mixture of two or more earths, but is as barren as the unmixed earths, because it contains very little putrescent matter, the only food for plants.

The qualities and value of soils depend on the proportions of their ingredients. We can easily comprehend in what manner silicious and aluminous earths, by their mixture, serve to cure the defects of each other-the open, loose, thirsty, and hot nature of sand being corrected by, and correcting in turn, the close, adhesive, and water holding qualities of aluminous earth. This curative operation is merely mechanical-and in that manner it seems likely that calcareous earth, when in large proportions, also acts, and aids the corrective powers of both the other earths. This however is only supposition, as I have met with scarcely any such natural soil.

But besides the mechanical effects of calcareous earth, (which perhaps are weaker than those of the other two,) that earth has chemical powers far more effectual in altering the texture of soils, and for which a comparatively small quantity is amply sufficient. The chemical action of calcareous earth as an ingredient of soils, will be fully treated of hereafter: it is only mentioned in this place to avoid the apparent contradiction which might be inferred, if, in a general description of calcareous earth, I had omitted all allusion to qualities that will afterwards be brought forward as all important.

*

The mixture of the three earths in due proportions, will correct the defects of all, and with a sufficiency of animal or vegetable matter, putres- It seems most proper to class and name soils accent, and soluble in water, a soil is formed in cording to their predominant earthy ingredients, by which plants can extend their roots freely, yet be which term, I mean those ingredients which exert firmly supported, and derive all their needful sup- the greatest power, and most strongly mark the plies of air, water, and warmth, without being character of the soil. The predominant ingreoppressed by too much of either. Such is the na- dient (in this sense,) is not always the most abuntural surface of almost all the habitable world: and dant, and frequently is the least. If the most though the qualities and value of soils are as va- abundant was considered the predominant ingrerious as the proportions of their ingredients are in-dient, and gave its name to the soil, then almost numerable, yet they are mostly so constituted, that every one should be called silicious, as that earth is no one earthly ingredient is so abundant, but that seldom equalled in quantity by all the others the texture of the soil is mechanically suited to united. If the earthy parts of a soil were twothirds silicious, and one-third of aluminous earth, would predominate over the opposing qualities of the peculiar qualities of the smaller ingredient the sand, and the mixture would be a tenacious clay. If the same soil had contained only onetwentieth part of calcareous earth, that ingredient would have had more marked effects on the soil, than could have been produced by either doubling, or diminishing to half their quantity, the silicious and aluminous earths, which formed the great bulk of the soil. If soils were named according to certain proportions of their ingredients, (as proposed by Davy,†) a correct, though limited ana

would have been useless and perhaps embarrassing to
readers in general.
* Cleaveland's Mineralogy-On Carbonate of Lime.
Cours Complet d'Agriculture, etc. par l'Abbé

Rozier-Terres.

Davy's Agr. Chem. page 110. Phil. Ed, 1821. § Putrescent or enriching manures, are those formed of vegetable and animal matters, capable of putrefying, and thereby furnishing soluble food to plants. Farm-yard and stable manure, and the weeds and other growth of the fields left to die and rot on them, are almost the only enriching manures that have been used as yet in this country,

The texture of a soil means the disposition of its parts, which produces such sensible qualities, as being close, adhesive, open, friable, &c.

proposed by Rozier-See article "
*Which is the plan of the nomenclature of soils
Terres," Cours
Complet d'Agriculture, etc. † Agr. Chem. p. 139,

lysis of a soil would be required, before its name | count of the poorest natural soils in our own poor or character could be given-and even then the country, which are as remarkable for their produname and character would often disagree. But cing luxuriant growths of pines, and broom grass, every farmer can know what are the most marked as for their unproductiveness in every cultivated or good or bad qualities of his soils, as shown under valuable crop. We are so accustomed to these tillage, and those qualities can be easily traced to facts, that we scarcely think of their singularity; their predominant ingredients. By compounding nor of the impropriety of calling any land barren, a few terms, various shades of difference may be which will produce a rapid growth of any one designated with sufficient precision. A few ex- plant. Indeed, by the rapidity of that growth, (or amples will be sufficient to show how all may be the fitness of the soil for its production,) we have applied:in some measure formed a standard of the poverty of the soil.

A silicious or sandy soil has such a proportion of silicious earth as to show more of its peculiar pro- With some exceptions to every general charac perties than those of any other ingredient. It ter, the tide-water district of Virginia may be dewould be more or less objectionable for its loose- scribed as generally level, sandy, poor, and free ness, heat, and want of power to retain either from any fixed rock, or any other than stones moisture or putrescent manure-and not for tough-rounded apparently by the attrition of water. On ness, liability to become hard after wet ploughing, or any other quality of aluminous earth.

In like manner, an aluminous or clayey soil, would show most strongly the faults of aluminous earth, though more than half its bulk might be of silicious.

The term loam is not essential to this plan, but it is convenient, as it will prevent the necessity of frequent compounds of other terms. It will be used for all soils formed with such proportions of sand and aluminous earth, as not to be light enough to be called sandy, nor stiff enough for clay soil. Sandy loam and clayey loum would express its two extremes-and loamy sand would be still lighter than the former, and loamy clay stiffer than the latter.

much the greater part of the lands, no stone of any kind is to be found, of larger size than gravel. Pines of different kinds form the greater part of a heavy cover to the silicious soils in their virgin state, and mix considerably with oaks, and other growth of clay land. Both these kinds of soil, after being exhausted of their little fertility by cultivation, and "turned out" to recruit, are soon covered by young pines which grow with vigor and luxuriance. This general description applies more particularly to the ridges which separate the slopes on different streams. The ridge lands are always level, and very poor-sometimes clayey, more generally sandy, but stiffer than would be inferred from the proportion of silicious earth they contain, which is caused by the fineness of its particles. Whortleberry bushes, as well as pines, are abundant on ridge lands-and numerous shallow basins are found, which are ponds of rain water in winter, but dry in summer. None of this large proportion of our lands, has paid the expense of clearing and cultivation, and much the greater part still remains under its native growth. Enough however has been cleared and cultivated in every neighborhood, to prove its utter worthlessness, under common management. The soils of ridge lands vary between sandy loam, and clayey loam. It is difficult to estimate their general product under cultivation; but judging from my own experience of such soils, the product may be from five bushels of corn, or as much of wheat, to the acre, on the most clayey soils, to twelve bushels of corn, and three ON THE SOILS, AND STATE OF AGRICULTURE of wheat on the most sandy if wheat were

In all compound names of soils, the last term should be considered as expressing the predominant earthy ingredient. Thus, a sandy loamy calcareous soil, would be nearer to loam than sand, and more marked by its calcareous ingredient than either. Other ingredients of soils besides the earths, or any accidental or rare quality affecting their character considerably, may be described with sufficient accuracy by such additional terms as these-a ferruginous gravelly silicious loam or a vegetable calcareous clay. [Appendix B.]

CHAPTER II.

OF THE TIDE-WATER DISTRICT OF VIR-
GINIA.

-" During several days of our jour"ney, no spot was seen that was not covered "with a luxuriant growth of large and beautiful "forest trees, except where they had been de"stroyed by the natives for the purpose of culti"vation. The least fertile of their pasture lands, "without seeding, are soon covered with grass "several feet in height; and unless prevented by "cultivation, a second growth of trees rapidly "springs up, which, without care or attention, at"tain their giant size in half the time that would "be expected on the best lands in England.".

there attempted to be made.

The slopes extend from the ridges to the streams, or to the alluvial bottoms, and include the whole interval between neighboring branches of the same stream. This class of soils forms another great body of lands-of a higher grade of fertility, though still far from valuable. It is generally more sandy than the poorer ridge land, and when long cultivated, is more or less deprived of its soil, by the washing of rains, on every slight declivity. The washing away of three or four inches in depth, exposes a steril subsoil (or forms a "gall") which continues thenceforth bare of all vegetation: a greater declivity of the surface serves to form gullies several feet in depth, the If the foregoing description was met with in a earth carried from which, covers and injures the "Journey through Hindoostan," or some equally adjacent lower land. Most of this kind of land unknown region, no European reader would doubt has been cleared, and greatly exhausted. Its virbut such lands were fertile in the highest degree- gin growth is often more of oak, hickory, and dogand even many of ourselves would receive the wood, than pine-but when turned out of cultivasame impression. Yet it is no exaggerated ac- tion, an unmixed growth of pine follows. Land

of this kind in general has very little durability; its | may differ on this head, there are but few who will usual best product of corn may be for a few crops, not concur in the opinion, that our system of culeighteen or twenty bushels-and even as much as ivation has been every year lessening the productive twenty-five bushels, from the highest grade. power of our lands in general-and that no one Wheat is seldom a productive or profitable crop county, no neighborhood, and but few particular on the slopes, the soil being generally too sandy. farms, have been at all enriched, since their first When such soils as these are called rich or valuable settlement and cultivation. Yet many of our farming (as most persons would describe them,) those operations have been much improved within the last terms must be considered as only comparative-fifteen or twenty years. Driven by necessity, propriand such an application of them proves that truly etors direct more personal attention to their farmsfertile and valuable soils, are very scarce in Lower better implements of husbandry are used-every Virginia. process is more perfectly performed-and whether well or ill directed, a spirit of inquiry and enterprise has been awakened, which before had no existence.

The only very rich and durable soils below the falls of our rivers, are narrow strips of highland along their banks, and the lowlands formed by the alluvion of the numerous smaller streams which water our country. These alluvial bottoms, though highly productive, are lessened in value by being generally too sandy, and by the damage they suffer from being often inundated by floods of rain. The best highland soils seldom extend more than half a mile from the river's edgesometimes not fifty yards. These irregular margins are composed of loams of various qualities, But all highly valuable; and the best soils are scarcely to be surpassed, in their original fertility, and durability under severe tillage. Their nature and peculiarities will be again adverted to, and more fully described hereafter.

the newly cleared. Sound calculations of profit and loss, would induce us to reduce the extent of our present cultivation, by turning out every acre that yields less than the total cost of its tillage.

Throughout the country below the falls, and perhaps thirty miles above, if the best land be excluded, say one-tenth, the remaining nine-tenths will not yield an average product of ten bushels of corn to the acre; though that grain is best suited to our soils in general, and far exceeds in quantity all other kinds raised. Of course, the product of a large proportion of the land, would fall below this average. Such crops, in very many cases, cannot remunerate the cultivator. If our remaining woodland could be at once brought into cultivation, the gross product of the country would be greatly increased, but the net product very probably diminished-as the general poverty of these lands would cause more The simple statement of the general course of expense than profit to accompany their cultivation tillage to which our part of the country has been under the usual system. Yet every year we are subjected, is sufficient to prove that great impover-using all our exertions to clear woodland, and in ishment of the soil has been the inevitable conse- fact seldom increase either net or gross products quence. The small portion of rich river margins, because nearly as much old exhausted land was soon all cleared, and was tilled without cessa- is turned out of cultivation as is substituted by tion for many years. The clearing of the slopes was next commenced, and is not yet entirely completed. On these soils, the succession of crops was less rapid, or from necessity, tillage was sooner suspended. If not rich enough for tobacco when No political truth is better established than that first cleared, (or as soon as it ceased to be so,) the population of every country will increase, or land of its kind was planted in corn two or three diminish, according to its regular supply of food. years in succession, and afterwards every second We know from the census of 1830, compared with year. The intermediate year between the crops those of 1820 and 1810, that our population is of corn, the field was "rested" under a crop of nearly stationary, and in some counties, is actually wheat, if it would produce four or five bushels to lessening; and therefore it is certain, that our ag If the sandiness, or exhausted condition riculture is not increasing the amount of food, or of the soil, denied even this small product of the means of purchasing food-with all the assiswheat, that crop was probably not attempted-tance of the new land annually brought under culand instead of it, the field was exposed to close ture. In these circumstances, a surplus populagrazing, from the time of gathering one crop of tion, with all its deplorable consequences, is only corn, to that of preparing to plant another. No prevented by the great current of emigration which manure was applied, except on the tobacco lots; is continually flowing westward. No matter who and this rotation of a grain crop every year, and afterwards every second year, was kept up as long as the field would produce five bushels of corn to When reduced below that product, and to less than the necessary expense of cultivation, the land was turned out to recover under a new growth of pines. After twenty or thirty years, according to the convenience of the owner, the same land would be again cleared, and put under similar scourging tillage, which however would then much sooner end, as before, in exhaustion. Such a general system is not yet every where abandoned and many years have not passed, since such was the usual course on almost every

the acre.

the acre.

farm.

How much our country has been impoverished during the last fifty years, cannot be determined by any satisfactory testimony. But however we

emigrates, or with what motive-the enterprising or wealthy citizen who leaves us to seek richer lands and greater profits, and the slave sold and carried away on account of his owner's poverty, concur in producing the same result, though with very different degrees of benefit to those who remain. If this great and continued drain from our population was stopped, and our agriculture was not improved, want and misery would work to produce the same results. Births would diminish, and deaths would increase-and hunger and disease would keep down population to that number, that the average products of our agricultural and other labor could feed, and supply with other means of living.

A stranger to our situation and habits might well oppose to my statements the very reasonable bjection, that no man would, or could, long pur