OPERATIONS.] AGRICULTUB E 337 ward the bottom than by using a turn-wrest plough across the slope. It is while giving this deep autumn furrow that the subsoil plough is used. It follows in the wake of the common plough, and breaks and stirs the subsoil, but without raising it to the surface. This is a laborious operation, and engrosses too much of the horse-power of the farm to admit of large breadths being overtaken in any one season. In all indurated subsoils, however, it repays its cost ; for when once thoroughly done, it diminishes the labour of ordinary ploughings for several succeeding rota tions, aids the drainage, and adds to the fertility of the soil. It is in the performance of this deep autumn tillage and breaking up of the subsoil, that the steam-engine, with appropriate tackle, has begun to play an important part, and for which it will probably one day supersede all other msans. Section 2. Harrowing, &c. The harrow, cultivator, and roller, are all more simple in their action and more easily managed than the plough. Har rowing is most effective when the horses step briskly along. The tines are then not merely drawn through the soil, but, in their combined swinging and forward movement, strike into it with considerable force. It is with reference to this that a single application of this implement is called a stroke of the harrows. Rollers are used to aid in pulveris ing and cleaning the soil, by bruising clods and lumps of tangled roots and earth which the other implements have brought a-top ; in smoothing the surface for the reception of small seeds, or the better operation of the scythe and other implements ; and for consolidating soil that is too loose in its texture. Except for the latter purpose, light rollers are much superior to heavy ones. When it is wanted, for example, to bruise clots of quickens, that the after harrowing may more thoroughly free the roots from the adhering earth, a light cast-iron roller, say of 5 cwt., drawn by one horse, effects this purpose as thoroughly as one double the weight drawn by a pair, and does it, moreover, in much less time, at less than half the expense, and without in juriously consolidating the free soil. These light rollers are conveniently worked in pairs, the ploughman driving one horse and leading the other. With a pair of active horses, and such rollers, a good deal more than doiible the space can be rolled in a day, than by yoking them both to one heavy one of the same length of cylinder. For mere clod-crushing, provided the clods are moist, the Norwegian harrow is superior to any roller ; and for compressing a loose surface or checking wire-worm, serrated or smooth- edged discs, such as Crosskill s or Cambridge s, are better than smooth cylinders of the same weight, so that the heavy smooth roller, requiring two or more horses to draw it, is superseded by better implements for all purposes where rollers are used at all, unless it be for the rolling of the grass-lands. As a general rule, none of these tillage operations can be performed to advantage when the soil is wet. When rain falls inopportunely there is a strong temptation to push on the field operations, before the soil has recovered the proper state of dryness. When this is done the farmer almost invariably finds in the issue that the more haste he makes the worse he speeds. Soils with a good deal of clay in their composition are peculiarly susceptible of injury in this way. Nice discrimination is needed to handle them aright. They require, moreover, a full stock of well-conditioned horses, that the work may be pushed rapidly through in favourable weather. To manage such soils success fully, especially when root crops are grown, tries the skill of the farmer to the utmost. So at least it has hitherto been ; but with steam-power to aid him, there is now a probability that the clay land farmer, by being able to break up his soil without treading it, and to get through with a large extent of tillage when his land is in trim for it, may find it practicable to grow root crops on equal terms with the occupier of freer soil. Section 3. Fallowing. When, by such operations as have now been described. land has been reclaimed from its natural state, and rendered fit for the purposes of the husbandman, it is everywhere so charged with the germs of weeds, most of which possess in a remarkable degree the power of reproduction and multiplication, that it is only by the most incessant and vigorous efforts he can restrain them from encroaching upon his cultivated crops, and regaining entire possession of the soil. He can do much towards this by ordinary tillage, and by sowing his crops in rows, and hoeing in the inter vals during the early stages of their growth. But if his efforts are restricted to such measures only, the battle will soon go against him. Besides this, all arable soils in which clay predominates, particularly when undrained, have such a determined tendency to become compact and soured, that under ordinary efforts they fail to yield a genial seed bed. There is a necessity, therefore, for having recourse, from time to time, to that ameliorating process of lengthened tillage called fallowing. This process begins in autumn, immediately after the removal from the ground of the cereal crop, which had been sown upon the land newly broken up from clover lea or natural sward, and extends either to the time for sowing turnips and analogous crops in the following spring, or is continued during the entire summer in preparation for autumn-sown wheat We shall first describe that modification of the fallowing process by which the soil is prepared for the sowing of drilled green crops, and then the more prolonged form of it usually called summer or naked fallow. Green Crop Fallow. The object aimed at being the thorough disintegration and cleaning of the soil, the usual practice is to begin by ploughing as deeply as is found practicable. This first or autumn furrow is accordingly turned over to a depth of 8 or 9 inches ; or by using a stronger plough drawn by three or four horses, it is carried to 1 2 inches in depth ; and in some cases, by following with a subsoil plough in the wake of the common one, the soil is stirred to the depth of 14 or 16 inches. All cultivators are agreed as to the importance of thus deeply and effectually disintegrating all soils that are naturally dry or thoroughly drained. In the case of undrained lands, and even of very unctuous clays, although well drained, such deep stirring of the soil in autumn does but increase its capacity of retaining the rains of winter, and of being thereby more effectually soured, and is therefore to be avoided. Assuming, however, that we have to do with soil thoroughly drained and moderately friable, it is undoubtedly beneficial to loosen it deeply and thoroughly at this stage. But before this deep ploughing is set about, it will be worth while to consider well its bearing upon the cleaning part of the process. On carefully examining the fields at the time of reaping the grain-crops, and from week to week thereafter, the roots of the couch- grass are found at first lying close to the surface ; but in stantly, on their getting the ground to themselves, they begin to send out fresh fibres, and to push their shoots deeply into the soil. In these circumstances, to proceed at once, according to the customary practice, to plough deeply, allows these weeds much time to increase, while this laborious and tedious operation is going on; and although, when performed, it gives some present check to their progress, by burying them under a mass of loosened soil, it not only increases the difficulty of their after removal, but places them out of the reach of frost, and in the beat
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