Then, too, the effects of excessive cold and heat in various places are similar; thus, for instance, Thrace is fruitful in corn, by reason of the cold, while Africa and Egypt are so in consequence of the heat that prevails there. At Chalcia,[2847] an island belonging to the Rhodians, there is a certain place which is so remarkably fertile, that after reaping the barley that has been sown at the ordinary time, and gathering it in, they immediately sow a fresh crop, and reap it at the same time as the other corn. A gravelly soil is found best suited for the olive in the district of Venafrum,[2848] while one of extreme richness is required for it in Bætica. The wines of Pucinum[2849] are ripened upon a rock, and the vines of Cæcubum[2850] are moistened by the waters of the Pomptine[2851] marshes; so great are the differences that have been detected by human experience in the various soils. Cæsar Vopiscus, when pleading a cause before the Censors, said that the fields of Rosia[2852] are the very marrow[2853] of Italy, and that a stake, left in the ground there one day, would be found covered by the grass the next:[2854] the soil, however, is only esteemed there for the purposes of pasturage. Still, however, Nature has willed that we should not remain uninstructed, and has made full admission as to existing defects in soil, even in cases where she has failed to give us equal information as to its good qualities: we shall begin, therefore, by speaking of the defects that are found in various soils.
(5.) If it is the wish of a person to test whether a soil is bitter, or whether it is thin and meagre, the fact may be easily ascertained from the presence of black and undergrown herbs. If, again, the herbage shoots up dry and stunted, it shows that the soil is cold, and if sad and languid, that it is moist and slimy. The eye, too, is able to judge whether it is a red earth or whether it is argillaceous, both of them extremely difficult to work, and apt to load the harrow or ploughshare with enormous clods; though at the same time it should be borne in mind that the soil which entails the greatest amount of labour is not always productive of the smallest amount of profit. So, too, on the other hand, the eye can distinguish a soil that is mixed with ashes or with white sand, while earth that is sterile and dense may be easily detected by its peculiar hardness, at even a single stroke of the mattock.
Cato,[2855] briefly and in his peculiar manner, characterizes the defects that exist in the various soils. “Take care,” he says, “where the earth is rotten not to shake it either with carts or by driving cattle over it.” Now what are we to suppose that this term “rotten” means, as applied to a soil, about which he is so vastly apprehensive as to almost forbid our setting foot upon it? Let us only form a comparison by thinking what it is that constitutes rottenness in wood, and we shall find that the faults which are held by him in such aversion are the being arid, full of holes, rough, white, mouldy, worm-eaten, in fact, just like pumice-stone; and thus has Cato said more in a single word than we could have possibly found means to express in a description, however long. Indeed, if we could find means of expressing the various defects that exist in soils, we should find that there are some of them that are old, not with age (for age cannot[2856] be concerned in relation to the earth), but of their own nature, and are hence unfruitful and powerless for every purpose from the first. The same writer,[2857] too, considers that as the very best of soils, which, situate at the foot of a declivity, runs out into a champaign country, taking a southward direction; such, in fact, being the aspect of the whole of Italy:[2858] he says[2859] also, that the earth generally known as black[2860] earth is of a tender nature, and is consequently the most easily worked and the best for cereals. If we only appreciate with due care the signification of this word “tender,”[2861] we shall find that it expresses its intended meaning remarkably well, and that in this word is comprised every quality that is desirable for the purposes of cultivation. In a tender soil we shall find fertility combined with moderation, a softness and a pliancy easily adapted to cultivation, and an equal absence of humidity and of dryness. Earth of this nature will shine again after the plough-share has passed through it, just as Homer,[2862] that great fountain-head of all genius, has described it sculptured by the Divinity[2863] upon the arms [of Achilles], adding, too, a thing that is truly marvellous, that it was of a blackish hue, though gold was the material in which it was wrought. This, too, is that kind of earth, which, when newly turned up, attracts the ravenous birds that follow the plough-share, the ravens even going so far as to peck at the heels of the ploughman.
We may in this place appropriately make mention of an opinion that has been pronounced by an Italian writer also with reference to a matter of luxury. Cicero,[2864] that other luminary of literature, has made the following remark: “Those unguents which have a taste of earth[2865] are better,” says he, “than those which smack of saffron;” it seeming to him more to the purpose to express himself by the word “taste”[2866] than “smell.” And such is the fact, no doubt; that soil is the best which has the flavour of a perfume.[2867] If the question should be put to us, what is this odour of the earth that is held in such estimation, our answer is, that it is the same that is often to be recognized at the moment of sunset, without the necessity even of turning up the ground, at the spots where the extremities of the rainbow[2868] have been observed to meet the earth; as also when, after long-continued drought, the rain has soaked the ground. Then it is that the earth exhales this divine odour, that is so peculiarly its own, and to which, imparted to it by the sun, there is no perfume, however sweet, that can possibly be compared. It is this odour that the earth, when turned up, ought to emit, and which, when once found, can never deceive a person; and this will be found the best criterion for judging of the quality of the soil. Such, too, is the odour that is usually perceived on land newly cleared,[2869] when an ancient forest has been just cut down; its excellence is a thing that is universally admitted.
For the culture of the cereals, too, the same land is generally looked upon as the more improved the oftener it has been allowed to rest[2870] from cultivation, a thing that is not the case with vineyards; for which reason all the greater care is required in the selection of their site, if we would not have the opinions of those to appear well founded who entertain the notion that the soil of Italy is already worn out.[2871] In other kinds of soil the work of cultivation depends entirely upon the weather; as, for instance, in those which cannot be ploughed just after rain, because the natural exuberance of the earth renders it viscous and cloggy. On the other hand, in Byzacium, a district of Africa, and a champaign country of such singular fertility as to render grain one hundred and fifty fold,[2872] the soil is such, that in time of drought, not even bulls are able to plough it; while, on another occasion, just after a shower of rain, one poor ass, with an old woman to guide it, is quite sufficient,[2873] as ourselves we have witnessed, to do the ploughing. But as to amending one soil by the agency of another, as some persons recommend, by throwing rich earth over one that is poor and thin, or by laying a soaking light soil over one that is humid and unctuous, it is a labour of perfect madness.[2874] What can a man possibly hope for who cultivates such a soil as this?
CHAP. 4. (6.)—THE EIGHT KINDS OF EARTH BOASTED OF BY THE GAULS AND GREEKS.
There is another method, which has been invented both in Gaul and Britain, of enriching earth by the agency of itself, being * * * * and that kind known as marl.[2875] This soil is looked upon as containing a greater amount of fecundating principles, and acts as a fat in relation to the earth, just as we find glands existing in the body, which are formed by a condensation of the fatty particles into so many kernels. (7.) This mode of proceeding, too, has not been overlooked by the Greeks; indeed, what subject is there that they have not touched upon? They call by the name of leucargillon[2876] a white argillaceous earth which is used in the territory of Megara, but only where the soil is of a moist, cold nature.
It is only right that I should employ some degree of care and exactness in treating of this marl, which tends so greatly to enrich the soil of the Gallic provinces and the British islands. There were formerly but two varieties known, but more recently, with the progress of agricultural knowledge, several[2877] others have begun to be employed; there being, in fact, the white, the red, the columbine, the argillaceous, the tufaceous, and the sandy marls. It has also one of these two peculiarities, it is either rough or greasy to the touch; the proper mode of testing it being by the hand. Its uses, too, are of a twofold nature—it is employed for the production of the cereals only, or else for the enrichment of pasture land as well. The tufaceous[2878] kind is nutrimental to grain, and so is the white; if found in the vicinity of springs, it is fertile to an immeasurable extent; but if it is rough to the touch, when laid upon the land in too large a quantity, it is apt to burn up the soil. The next kind is the red marl, known as acaunumarga,[2879] consisting of stones mingled with a thin sandy earth. These stones are broken upon the land itself, and it is with considerable difficulty during the earlier years that the stalk of the corn is cut, in consequence of the presence of these stones; however, as it is remarkably light, it only costs for carriage one-half of the outlay required in using the other varieties. It is laid but very thinly on the surface, and it is generally thought that it is mixed with salt. Both of these varieties, when once laid on the land, will fertilize it for fifty[2880] years, whether for grain or for hay.
(8.) Of the marls that are found to be of an unctuous nature, the best is the white. There are several varieties of it: the most pungent and biting being the one already mentioned. Another kind, is the white chalk that is used for cleaning[2881] silver; it is taken from a considerable depth in the ground, the pits being sunk, in most instances, as much as one hundred feet. These pits are narrow at the mouth, but the shafts enlarge very considerably in the interior, as is the case in mines; it is in Britain more particularly that this chalk is employed. The good effects of it are found to last full eighty years; and there is no instance known of an agriculturist laying it twice on the same land during his life.[2882] A third variety of white marl is known as glisomarga;[2883] it consists of fullers’ chalk[2884] mixed with an unctuous earth, and is better for promoting the growth of hay than grain; so much so, in fact, that between harvest and the ensuing seed-time there is cut a most abundant crop of grass. While the corn is growing, however, it will allow no other plant to grow there. Its effects will last so long as thirty years; but if laid too thickly on the ground, it is apt to choke up the soil, just as if it had been covered with Signine[2885] cement. The Gauls give to the columbine marl in their language the name of eglecopala;[2886] it is taken up in solid blocks like stone, after which it is so loosened by the action of the sun and frost, as to split into laminæ of extreme thinness; this kind is equally beneficial for grass and grain. The sandy[2887] marl is employed if there is no other at hand, and on moist slimy soils, even when other kinds can be procured.
The Ubii are the only people that we know of, who, having an extremely fertile soil to cultivate, employ methods of enriching it; wherever the land may happen to be, they dig to a depth of three feet, and, taking up the earth, cover the soil with it in other places a foot in thickness; this method, however, to be beneficial, requires to be renewed at the end of every ten years. The Ædui and the Pictones have rendered their lands remarkably fertile by the aid of limestone, which is also found to be particularly beneficial to the olive and the vine.[2888] Every marl, however, requires to be laid on the land immediately after ploughing, in order that the soil may at once imbibe its properties; while at the same time, it requires a little manure as well, as it is apt, at first, to be of too acrid a nature, at least where it is not pasture land that it is laid upon; in addition to which, by its very freshness it may possibly injure the soil, whatever the nature of it may be; so much so, indeed, that the land is never fertile the first year after it has been employed. It is a matter of consideration also for what kind of soil the marl is required; if the soil is moist, a dry marl is best suited for it; and if dry, a rich unctuous marl. If, on the other hand, the land is of a medium quality, chalk or columbine[2889] marl is the best suited for it.