Tillage is breaking and dividing the Ground by Spade, Plough, Hoe, or other Instruments, which divide by a Sort of Attrition (or Contusion) as Dung does by Fermentation[22].
[22]Neque enim aliud est Colere quam Resolvere, & Fermentare Terram. Columella.
And since the artificial Pasture of Plants is made and increas’d by Pulveration, ’tis no Matter whether it be by the Ferment of Dung, the Attrition of the Plough, the Contusion of the Roller, or by any other Instrument or Means whatsoever, except by Fire, which carries away all the Cement of that which is burnt.
By Dung we are limited to the Quantity of it we can procure, which in most Places is too scanty: But by Tillage, we can inlarge our Field of subterranean Pasture without Limitation, tho’ the external Surface of it be confin’d within narrow Bounds: Tillage may extend the Earth’s internal Superficies, in proportion to the Division of its Parts; and as Division is infinite, so may that Superficies be.
Every Time the Earth is broken by any Sort of Tillage, or Division, there must arise some new Superficies of the broken Parts, which never has been open before. For when the Parts of Earth are once united and incorporated together, ’tis morally impossible, that they, or any of them, should be broken again, only in the same Places; for to do that, such Parts must have again the same numerical Figures and Dimensions they had before such Breaking, which even by an infinite Division could never be likely to happen: As the Letters of a Distichon, cut out and mixt, if they should be thrown up never so often, would never be likely to fall into the same Order and Position with one another, so as to recompose the same Distich.
Although the internal Superficies may have been drain’d by a preceding Crop, and the next Plowing may move many of the before divided Parts, without new-breaking them; yet such as are new-broken, have, at such Places where they are so broken, a new Superficies, which never was, or did exist before; because we cannot reasonably suppose, that any of those Parts can have in all places (if in any Places) the same Figure and Dimensions twice.
For as Matter is divisible ad infinitum, the Places or Lines whereat ’tis so divisible, must be, in relation to Number, infinite, that is to say, without Number; and must have at every Division Superficies of Parts of infinite Variety[23] in Figure and Dimensions.
[23]Their Variety is such, that ’tis next to impossible, any two Pieces, or Clods, in a Thousand Acres of till’d Ground, should have the same Figure, and equal Dimensions, or that any Piece should exactly tally with any other, except with that from whence it was broken off.
And because ’tis morally impossible, the same Figure and Dimensions should happen twice to any one Part, we need not wonder, how the Earth, every time of Tilling, should afford a new internal Superficies (or artificial Pasture); and that the till’d Soil has in it an inexhaustible Fund, which by a sufficient Division (being capable of an infinite one) may be produc’d.
Tillage (as well as Dung) is beneficial to all Sorts of Land[24]. Light Land, being naturally hollow, has larger Pores, which are the Cause of its Lightness: This, when it is by any Means sufficiently divided, the Parts being brought nearer together, becomes, for a time, Bulk for Bulk, heavier; i. e. The same Quantity will be contain’d in less Room, and so is made to partake of the Nature and Benefits of strong Land, viz. to keep out too much Heat and Cold, and the like.
[24]’Tis of late fully prov’d, by the Experience of many Farmers, that two or three additional Plowings will supply the Place of Dung, even in the old Husbandry, if they be perform’d at proper Seasons: and the hiring Price of three Plowings, after Land has been thrice plow’d before, is but Twelve Shillings, whereas a Dunging will cost three Pounds: This was accidentally discovered in my Neighbourhood, by the Practice of a poor Farmer, who, when he had prepared his Land for Barley, and could not procure Seed to sow it, plow’d it on till Wheat Seed-Time, and (by means of such additional Plowing) without Dung, had so good a Crop of Wheat, that it was judg’d to be more than the Inheritance of the Land it grew on.
The same Effect follows when they prepare Land for Turneps, since they are come in Fashion, and sow them several Times upon several Plowings, the Fly as often taking them off; they have from such extraordinary Tillage a good Crop of Wheat, instead of the lost Turneps, without the Help of Dung; hence double-plowing is now become frequent in this Country.
The Reason why Land is enrich’d by lying long unplow’d, is that so very few Vegetables are carried off it, very little being produc’d; the Exhaustion is less than what is added by the Atmosphere, Cattle, &c. But when ’tis plow’d, a vastly greater Quantity of Vegetables is produc’d, and carried off, more than by the old Husbandry is return’d to it.
But strong Land, being naturally less porous, is made for a Time lighter (as well as richer) by a good Division; the Separation of its Parts makes it more porous, and causes it to take up more Room than it does in its natural State; and then it partakes of all the Benefits of lighter Land.
When strong Land is plow’d, and not sufficiently, so that the Parts remain gross, ’tis said to be rough, and it has not the Benefit of Tillage; because most of the artificial Pores (or Interstices) are too large; and then it partakes of the Inconveniences of the hollow Land untill’d.
For when the light Land is plow’d but once, that is not sufficient to diminish its natural Hollowness (or Pores;) and, for Want of more Tillage, the Parts into which ’tis divided by that once (or perhaps twice) Plowing, remain too large; and consequently the artificial Pores are large also, and, in that respect, are like the ill-till’d strong Land.
Light-land, having naturally less internal Superficies, seems to require the more Tillage[25] or Dung to enrich it; as when the poor, hollow, thin Downs have their upper Part (which is the best) burnt, whereby all, (except a Caput Mortuum) is carried away; yet the Salts of this spread upon that barren Part of the Staple, which is unburnt, divide it into so very minute Particles, that their Pasture will nourish two or three good Crops of Corn: But then the Plough, even with a considerable Quantity of Dung, is never able afterwards to make a Division equal to what those Salts have done; and therefore such burnt Land remains barren.
[25]As for puffy Land, which naturally swells up, instead of subsiding, tho’ its Hollowness is much abated by Tillage, yet it is thought little better than barren Land, and unprofitable for Corn: But what we usually call Light-land, is only comparatively so, in Respect of that which is heavier and stronger. And this Sort of Light land becomes much lighter by being ill-till’d; the unbroken Pieces of Turf underneath undissolved, forming large Cavities, increase its Hollowness, and consequently its Lightness: I have often known this Sort of Land despis’d by its Owners, who fear’d to give it due Tillage, which they thought would make it so light, that the Wind would blow it away; but whenever such has been thoroughly till’d, it never fail’d to become much stronger than before; and considering that ’tis till’d with less Expence than very strong Land, it is, for several Sorts of Corn, found to be more profitable than Land of greater Strength and Richness, that is more difficult to be till’d.
And I am apt to think, that this Sort of Light-land acquires more Cement, by having its external Superficies often changed, and exposed to the Dews, and other Benefits of the Atmosphere, as well as by the Increase of (its internal Superficies, which is the Surfaces of all the divided Parts of Earth, or) the Pasture of Plants; the one being augmented by the other; i. e., that into the more Parts the Earth is broken, the more Cement will it attain, from the Sulphur, which is brought by the Dews.
Artificial Pores cannot be too small, because Roots may the more easily enter the Soil that has them, quite contrary to natural Pores; for these may be, and generally are, too small, and too hard for the Entrance of all weak Roots, and for the free Entrance of strong Roots.
Insufficient Tillage leaves strong Land with its natural Pores too small, and its artificial ones too large. It leaves Light-land, with its natural and artificial Pores both too large.
Pores that are too small in hard Ground, will not easily permit Roots to enter them.
Pores that are too large in any Sort of Land, can be of little other Use to Roots, but only to give them Passage to other Cavities more proper for them; and if in any Place they lie open to the Air, they are dry’d up, and spoil’d, before they reach them.
For fibrous Roots (which alone maintain the Plant; the other Roots serve for receiving the Chyle from them, and convey it to the Stem) can take in no Nourishment from any Cavity, unless they come into Contact with[26], and press against, all the Superficies of that Cavity, which includes them; for it dispenses the Food to their Lacteals by such Pressure only: But a fibrous Root is not so press’d by the Superficies of a Cavity whose Diameter is greater than that of the Root.
[26]Roots cannot have any Nourishment from Cavities of the Earth that are too large to press against them, except what Water, when ’tis in great Quantity, brings to them, which is imbibed by the gentle Pressure of the Water; but when the Water is gone, those large Cavities being empty, the Pressure ceases; and this is the Reason, that when Land has few other but such large Cavities, the Plants in it always suffer more by dry Weather, than in Land which by Dung or Tillage has more minute and fewer large Cavities.
There may be some Moisture on the Superficies of large Cavities; but without Pressure the fibrous Roots cannot reach it; and very little or no Pressure can be made to one Part of the Root’s Superficies, unless the Whole that is included be pressed.
If it be objected that a Charlock-Plant, when pulled up, and thrown upon the Ground, will grow thereon; this proves nothing against the Necessity of Pressure, &c. for the Weight of that Plant presses some of its Roots so closely against the Ground, that they send out (unless the Weather be very dry) new Fibres into the Earth; and there they are pressed in all their Superficies; without which Fibres the Plant doth not grow.
The Surfaces of great Clods form Declivities on every Side of them, and large Cavities, which are as Sinks to convey, what Rain and Dew bring, too quickly downwards to below the plow’d Part.
The first and second Plowings with common Ploughs scarce deserve the Name of Tillage; they rather serve to prepare the Land for Tillage.
The third, fourth, and every subsequent Plowing, may be of more Benefit, and less Expence, than any of the preceding ones.
But the last Plowings will be more advantageously perform’d by Way of Hoeing, as in the following Chapters will appear.
For the finer Land is made by Tillage, the richer will it become, and the more Plants it will maintain.
It has been often observ’d, that when Part of a Ground has been better till’d than the rest, and the whole Ground constantly manag’d alike afterwards for six or seven Years successively; this Part that was but once better till’d, always produc’d a better Crop than the rest, and the Difference remain’d very visible every Harvest.
One Part being once made finer, the Dews did more enrich it; for they penetrate within and beyond the Superficies, whereto the Roots are able to enter: The fine Parts of the Earth are impregnate, throughout their whole Substance, with some of the Riches carried in by the Dews, and there reposited; until, by new Tillage, the Insides of those fine Parts become Superficies; and as the Corn drains them, they are again supply’d as before; but the rough large Parts cannot have that Benefit; the Dews not penetrating to their Centres, they remain poorer.
I think nothing can be said more strongly to confirm the Truth of this, than what is related by the Authors quoted by Mr. Evelyn[27], to this Effect, viz.
[27]In Pag. 17, 18, and 19, of his Phil. Discourse of Earth.
‘Take of the most barren Earth you can find, pulverize it well, and expose it abroad for a Year, incessantly agitated[28]; it will become so fertile as to receive an exotic Plant from the furthest Indies; and to cause all Vegetables to prosper in the most exalted Degree, and to bear their Fruit as kindly with us as in their natural Climates.’
[28]i. e. Stirr’d often.
This artificial Dust[29], he says, will entertain Plants which refuse Dung, and other violent Applications; and that it has a more nutritive Power than any artificial Dungs or Compost whatsoever: And further, that by this Toil of pulverizing, “’tis found, that Soil may be so strangely alter’d from its former Nature, as to render the harm and most uncivil Clay[30] obsequious to the Husbandmen, and to bring forth Roots and Plants, which otherwise require the lighted and hollowest Mould[31].”
[29]Tho’ it may be impossible for the Plough to reduce the whole Staple into so fine Powder, yet the more internal Superficies it makes, the more Dust will be made by the Atmosphere in Proportion; and great Clods perhaps are of no Use to Plants, but by that Dust they let fall, being thence extricated by the insensible Ferment of the nitrous Air; and the Surfaces of this artificial Dust must receive such Operations from the Air, before the utmost Fertility be obtain’d.
[30]But I take harsh uncivil Clay to be the least profitable of any to keep in Tillage.
[31]To this Dust, Namque hoc imitamur arando ought to be apply’d, and not to Putre Solum, which itself needs Tillage, as well as strong Land: But it seems the Antients did not observe the Difference between natural Pores (or Hollowness) and artificial ones, tho’ it is very great; as is shewn in Chap. of Pasture of Plants: ’Tis easier indeed to imitate this artificial Dust in hollow than in strong Land.
’Tis to be suppos’d, that the Indian Plants had their due Degrees of Heat and Moisture given them; and I should not chuse to bestow this Toil upon the poorest of Earth in a Field or Garden, tho’ that be the most sure wherein to make the Experiment[32].
[32]This is the most proper Trial of the Effect of Pulveration by pounding and grinding; but Land may be so barren, that Plough or Spade may not be sufficient to pulverize it to that Degree, which is necessary to give it the same Fertility, that Pounding in a Mortar, or grinding betwixt Marbles (as Colours are ground), can.
I never myself try’d this way of pounding or grinding, because impracticable in the Fields.
But I have had the Experience of a Multitude of Instances, which confirm it so far, that I am in no Doubt, that any Soil[33] (be it rich or poor) can ever be made too fine by Tillage[34].
[33]Land that is too hollow and light, having no Cement to join its Parts together, tho’ in Nature they are capable of infinite Division, yet in Practice the Plough cannot divide them to any Purpose, unless they were first join’d, but glides through without breaking them; being more like to the primary Particles of Water against the Plough, which are broken by no Force, than to Earth; it may be moved, but not broken by Tillage, and therefore ought not to be reputed arable; nor does it indeed deserve the Name of Land, but as the desart Sands of Lybia, to distinguish it from Sea.
[34]According to some, this Rule is only general, and not universal; for, say they, there’s a Sort of binding Gravel, that, when it is made fine, will, by a sudden Dash of Rain, run together like a Metal; and I have seen the same Accident in a particular Sort of white Land; but this very rarely happens to the latter: I never knew it above once, and that was after Barley was sown on it; the Hardness was only like a very thin Ice upon the Surface, which was some Hindrance to the coming up of the Barley, until the Harrow’s going over it once or twice broke that Ice or Crust, and then it came up very well.
I never had any other Sort of Land liable to this Misfortune: therefore can say nothing to the Gravel in that Case, nor how deep the Constipation may reach in it, nor what Remedy is most proper to prevent the ill Consequence of it: But if there should be two or three Exceptions out of One thousand Seventy-nine Millions One thousand and Sixty different Sorts of Earth (see Mr. Evelyn’s Terra, p. 2), ’twill be no great Matter.
But I think these are no real Exceptions against any Degree of Pulverizing; for it only shews, that some Sorts of Land, tho’ very few, are subject by Accident to lose too soon their Pulveration: And if the Fineness were no Benefit to that Land, such Loss of it would be no Injury to it.
For ’tis without Dispute, that one cubical Foot of this minute Powder may have more internal Superficies, than a thousand cubical Feet of the same, or any other Earth till’d in the common Manner; and, I believe no two arable Earths in the World do exceed one another in their natural Richness Twenty Times; that is, one cubical Foot of the richest is not able to produce an equal Quantity of Vegetables, cæteris paribus, to Twenty cubical Feet of the poorest; therefore ’tis not strange, that the poorest, when by pulverizing it has obtain’d One hundred Times the internal Superficies of the rich untill’d Land, it should exceed it in Fertility; or, if a Foot of the poorest was made to have Twenty Times the Superficies of a Foot of such rich Land, the poorest might produce an equal Quantity of Vegetables with the rich[35]. Besides, there is another extraordinary Advantage, when a Soil has a larger internal Superficies in a very little Compass; for then the Roots of Plants in it are better supply’d with Nourishment, being nearer to them on all Sides within Reach, than it can be when the Soil is less fine, as in common Tillage; and the Roots in the one must extend much further than in the other, to reach an equal Quantity of Nourishment: They must range and fill perhaps above twenty Times more Space to collect the same Quantity of Food.
[35]And very poor Land, well pulveriz’d, will produce better Corn than very rich will do, without Manure or Tillage. The Experiment may be made by paring off the Turf, and setting Corn in the whole Ground that is very rich; and that will shew how much the natural Pasture of the rich is inferior to the artificial Pasture of the poor Land; but then the poor must have this Proportion of Excess of internal Superficies continued to it, during the whole Time of their Growth, which cannot be done without frequently repeated Divisions of the Soil by Hoeing or Manure; else it might require forty Times the internal Superficies at the Time of Sowing, to keep twenty Times the internal Superficies of the rich till Harvest: For although the rich is continually losing some of its artificial Pasture, as well as the poor, yet by losing this equally, they still draw nearer and nearer to the first Inequality of their natural Pasture.
But poor Land, being lighter, has this Advantage, that it being more friable than the strong, requires less Labour to pulverize it; and therefore the Expence of it is much less, than in proportion to the Excess of Poorness of its internal Superficies.
But in this fine Soil, the most weak and tender Roots have free Passage to the utmost of their Extent, and have also an easy, due, and equal Pressure every-where, as in Water.
Hard Ground makes a too great Resistance, as Air makes a too little Resistance, to the Superficies of Roots.
Farmers, just when they have brought their Land into a Condition fit to be further till’d to much greater Advantage, leave off, supposing the Soil to be fine enough, when, with the Help of Harrows, they can cover the Seed; and afterwards with a Roller they break the Clods; to the End that, if a Crop succeed, they may be able to mow it, without being hinder’d by those Clods: By what I could ever find, this Instrument, call’d a Roller, is seldom beneficial to good Husbands; it rather untills the Land, and anticipates the subsiding of the Ground, which in strong Land happens too soon of itself[36].
[36]This Injury the Roller does, is only when tis used to press down the Earth after the Seed is sown; and is the greater, if Land be moist; but the Rolling of it in dry Weather, when ’tis to be immediately plow’d up again, is the most speedy Way to pulverize the Soil; and the Harrow is then very useful in pulling up the Clods, to the End that the Roller may the better come at them to crush them.
But more to blame are they, who neglect to give their Land due Plowing, trusting to the Harrow to make it fine; and when they have thrown in their Seed, go over it twenty Times with the Harrows[37] till the Horses have trodden it almost as hard as a Highway, which in moist Weather spoils the Crop; but on the contrary, the very Horses, when the Earth is moist, ought all to tread in the Furrows only, as in plowing with a Hoe-Plough they always do, when they use it instead of a common Plough.
[37]Nam veteres Romani dixerunt male subactum Agrum, qui satis Frugibus occandus sit.
Sed ut compluribus Iterationibus sic resolvatur vervactum in Pulverem, ut nullam vel exiguam desideret Occationem, cum seminaverimus. Col. Lib. 2. Cap. 4.