Two more earthings are usually given, but it is questionable whether even one be necessary in soil of average depth, unless there be a very wide interval between the drills, and it is certain that much earthing in dry and shallow soil is injurious ; for by withdrawing the earth from contiguity to the fibres which ramify and penetrate far in loose soil, and laying it on the head of the drill, and in the high ridgelet form, it is applied where it is useless for the nourishment of the tubers, and in a position that favours the rapid escape of moisture, which in such soil it ought to be an object to retain. In deep land, more particularly if it be of tenacious quality, the furrows at each side of the drill will be in general seasons most serviceable as drains, as well as for furnishing earth to support the sterns, while the moisture will be sufficiently retained for the roots.
Experiments have led to the inference that in soil of a. loose porous quality there is probably a greater produce by not affording any (or a very slight) moulding, but by digging instead between the rows; for deep and perfect pulverisation, next to an adequate allow ance of rich manure, is the main cause of a large produce. In propor tion to the deficiency of manure will be the necessity for opening the soil beneath, to allow the fibres, which may be distinctly traced to a depth incredible to those who have not followed their ramifications, to extract all the nourishment which the subsoil may afford. If there be an abundance of nutriment above, neither the necessity nor perhaps the inclination for penetrating deeply can exist, and in such cases the operation of earthing by the plough, as long as it can be introduced without injury to the stems, may be useful in many ways, but un questionably by guarding them from the effects of storm in exposed, and from excessive wetness in low situations. Besides, in regulating this point, regard should always be had to the quality of the potato, for the tubers of some varieties have a tendency to push to the surface, while others tend into the earth, and therefore require a different treatment.
But in all cases the earth should be rendered as loose and friable as possible, by spade, or plough ; and where labour is easily emu mantled, the spade will be found to ho the more etlicacioult implement In the first course of treatment after the plants are well up.
Some plant one or two pets in the centre of every square yard, but In sueb cameo great and continued earthing, until each square presents the form of a pyramid, is contemplated; and, if our preceding remarks be correct, this treatment is only applicable to deep and retentive soils. Great returns have no doubt been thus obtained, but by this mode there is the least possible Incorporation of the manure with the soil.
In minute husbandry, such as that exemplified In labourers' allot ments, which excludes the plough altogether, the ordinary and best practice is to lay the sets in rows, after a very deep winter digging. marked with a garden.line. The workman digs precisely as In a
garden.plot for cabbages : he clears a little drill, lays the seta straight, puts a sufficiency of manure over them, and then covers from the next spit, which ho digs with a spade or a three-pronged fork flattened at the end., levelling and pulverising as he advances to the distance at which he again puts down his lino and forms a new drill. Thus the entire piece is thoroughly loosened, the manure perfectly covered, and every facility given for the hand-hoeing in due course.
The next stage of the potato is that in which it blossoms. It has been recommended to pluck off the flowers. Excessive blossoming is no doubt injurious, but experience has generally proved that the extra cost is hardly defrayed by the additional produce obtained. If the flowers are plucked off, they should be nipped in the early bud.
When the crop is fully ripe, which is indicated by the withering of the stalks, and when the land is free from stones, labourers, in the proportion of about twenty to one plough (half of these being usually men, and the remainder women or young persona), should be set to pull up the stalks, and carefully collect the tubers which may be attached to them, before the plough proceeds in its operation. When it is prepared for work, the men, with prongs flattened at the extremity, are placed at such distances from each other as will give them proper time to fork out the potatoes cleanly for the pickers, who are also stationed at exact distances with a basket between every pair, into which they gather the potatoes.
The common airing-plough may be employed in three ways :—First, in taking off a slice from each side of every drill, and leaving it to the workmen to open out the centre with their prongs ; or in its third movement it may turn up this centre, under which the main body of the tubers lie, which is more expeditiously and easily done if the earth be in fit condition. Second, a double mould-board plough with a long sack, and divested of its coulter, may be drawn by two strong horses through the centre of the drills, and completely under the level of the tubers, so as to avoid injuring them, by which means the work-people will be kept exceedingly busy ; and if the land be in good friable order, this is the most expeditious mode, and, providing there is a perfect harrowing afterwards, the crop will be taken out with sufficient clean liness. Third, the crop may be taken up by prongs or long narrow spades without the plough. In wet weather this More tedious but far eider method is frequently adopted, and if the drills be short and the headrigga under crop also, it is the most desirable, effectual, and economical mode. In removing the produce in this manner, it is obvious that the number of gatherers should be much less in propor tion to the men than under the other circumstances. The headriggs should evidently be the first parts of the field cleared, to make a free space for the ploughs in the boutings, and for the carts.