"I have no hesitation in expressing my preference of trench to subsoil ploughing: and I cannot see a single instance, with the sole exception of turning up a very bad subsoil in large quantity, in which there is any advantage attending subsoil, that cannot be enjoyed by trench ploughing: and for this single drawback of a very bad subsoil, trenching has the advantage of being performed in perfect safety, where subsoil ploughing could not be, without previous drainage.
"But whilst giving a preference to trench ploughing over subsoil, I am of opinion that it should not be generally attempted under any circumstances, however favourable, without previous thorough-draining, any more than subsoil ploughing; but when so drained, there is no mode of management, in my opinion, that will render land so soon amenable to the means of putting it in a high degree of fertility as trench ploughing."—Vol. i. p. 664.
We confess that, in the first of the above passages, Mr. Stephens appears to us to assume something of the tone of a partizan, which has always the effect of lessening the weight of an author's opinion with the intelligent reader who is in search of the truth only. What is advanced as the main advantage of trench-ploughing in the first passage—that it can be safely done without previous draining, is in the second wholly discarded by the advice, never to trench-plough without previous draining. At the same time it is confessed, that in the case of a bad subsoil, trench-ploughing may do much harm. Every practical man in fact knows that bringing up the subsoil in any quantity, he would in some districts render his fields in a great measure unproductive for years to come. On the other hand, we believe that the use of the subsoil-plough can never do harm upon drained land. We speak, of course, of soils upon which it is already conceded that either the one method or the other ought to be adopted. The utmost evil that can follow in any such case from the use of the subsoil-plough, is that the expense will be thrown away—the land cannot be rendered more unfruitful by it. Subsoiling, therefore, is the safer practice.
But in reality, there ought, as we have already stated, to be no opposition between the two methods. Each has its own special uses for which it can be best employed, and the skill of the farmer must be exercised in determining whether the circumstances in which he is placed are such as to call specially for the one or for the other instrument. If the subsoil be a rich black mould, or a continuation of the same alluvial or other fertile soil which forms the surface—it may be turned up at once by the trench-plough without hesitation. Or, if the subsoil be more or less full of lime, which has sunk from above, trenching may with equal safety be adopted. But, if the subsoil be more or less ferruginous—if it be of that yellow unproductive clay which in some cases extends over nearly whole counties—or of that hard, blue, stony till which requires the aid of the mattock to work out of the drains—or if it consist of a hard and stony, more or less impervious bed—in all these cases the use of the subsoil-plough is clearly indicated. In short, the young farmer can scarcely have a safer rule than this—to subsoil his land first, whenever there is a doubt of the soundness of the subsoil, or a fear that by bringing it to the surface, the fertility of the upper soil will be diminished. It is no reply to this safer practice to say that even Mr. Smith recommends turning up the subsoil afterwards, and that we have therefore a double expense to incur. For it is known, that after a time any subsoil so treated may be turned up with safety, and consequently there is no risk of loss by delaying this deeper ploughing for a few years; and in regard to the question of expense, it appears that the cost of both draining and subsoiling are generally repayed by the first two or three crops which succeed each improvement. What more, then, can be required? The expense is repaid—the land is, to a certain extent, permanently improved—no risk of loss has been incurred, and there still remains to the improving farmer—improving his own circumstances, as well as the quality of his land, by his prudent and skilful measures—there still remains the deeper ploughing, by which he can gradually bring new soil to the surface, as he sees it mellow, and become wholesome, under the joint influences which the drain and the subsoil-plough have brought to bear upon it.
There can, therefore, it is clear, be no universal rule for the use of the two valuable instruments in question, as each has its own defined sphere of action. This, we think, is the common-sense view of the case. But if any one insists upon having a universal rule which shall save him from thinking or observing for himself in all cases, then we should say—in all cases subsoil, because it is the safer.
With this subject the first volume of The Book of the Farm is brought to a close; but winter still continues, and in other winter-work of scarcely less importance the young farmer has still to be instructed. We have hitherto said nothing of the more expensive and beautiful embellishments of the book, because the most interesting of them are portraits of celebrated short-horns, working horses, sheep, and pigs—a subject of which the author begins to treat only at the commencement of the second volume. The feeding of stock is one of those parts of the winter's labours, in improving husbandry, upon which not only the immediate profit of the farmer, but the ultimate fertility of his land, in a great measure depends. The choice of his stock, and the best mode of treating and tending them, therefore, are subjects of the greatest consequence to the young farmer. In the choice of his stock he will be aided at once by the clear descriptions, and by the portraits so beautifully executed by Landseer and Sheriff, by which the letterpress is accompanied. In the subsequent treatment of them, and in the mode by which they may be most profitably, most quickly, or most economically fed in the winter season, he will be fully instructed in the succeeding chapters of the book.
Turnips and other roots are the principal food of cattle in the winter: a preliminary chapter, therefore, is devoted to the "drawing and storing of turnips and other roots." Had we our article to begin again, we could devote several pages, agreeably to ourselves, and not without interest, we believe, or without instruction, to our reader, in discussing a few of those points connected with the feeding of cattle, upon which, though the means of information are within their reach, practical men have hitherto permitted themselves to remain wholly ignorant. Of these points Mr. Stephens adverts to several, and suggests the advantage of additional experiments; but the whole subject requires revision, and, under the guidance of persons able to direct, who are acquainted with all that is yet known, or has as yet been done either in our own or in foreign countries, experiments will hereafter, no doubt, be made, by which many new truths, both theoretically and practically valuable, are sure to be elucidated.
We may advert, as an illustration, to the feeding properties of the turnip. It is usual to reckon the value of a crop of turnips by the number of tons per acre which it is found to yield when so many square yards of the produce are weighed. But this may be very fallacious in many ways. If they are white turnips, for instance, nine tons of small will contain as much nourishment as ten tons of large—or twenty-seven tons an acre of small turnips will feed as many sheep as thirty tons per acre of large turnips. Or if the crop be Swedes, the reverse will be the case, twenty-seven tons of large will feed as much stock as thirty tons of small.—(Vol. ii., p. 20.) Mr. Stephens points out other fallacies also, to which we cannot advert. One, however, he has passed over, of equal, we believe of greater, consequence than any other—we allude to the variable quantity of water which the turnip grown on different soils in different seasons is found to contain.
It is obvious, that in so far as the roots of the turnip, the carrot, and the potatoe, consist of water, they can serve the purposes of drink only—they cannot feed the animals to which they are given. Now, the quantity of water in the turnip is so great, that 100 tons sometimes contain only nine tons of dry feeding matter—more than nine-tenths of their weight consisting of water. But again, their constitution is so variable, that 100 tons sometimes contain more than twenty tons of dry food—or less than four-fifths of their weight of water. It is possible, therefore, that one acre of turnips, on which only twenty tons are growing, may feed as many sheep as another on which forty tons are produced. What, therefore, can be more uncertain than the feeding value of an acre of turnips as estimated by the weight? How much in the dark are buyers and sellers of this root? What wonder is there, that different writers should estimate so very differently the weight of turnips which ought to be given for the purpose of sustaining the condition, or of increasing the weight, of the several varieties of stock? Other roots exhibit similar differences; and even the potatoe, while it sometimes contains thirty tons of food in every hundred of raw roots, at others, contains no more than twenty—the same weight, namely, which exists at times in the turnip. [4]
[Footnote 4: For our authority on this subject, we refer to Johnston's Suggestion for Experiments in Practical Agriculture, No. 111. pp. 62 and 64, of which we have been favoured with an early copy by the author.]