Part 11

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 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.

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, 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.

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, to this Effect, viz.

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; 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.’

i. e. Stirr’d often.

This artificial Dust, 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 obsequious to the Husbandmen, and to bring forth Roots and Plants, which otherwise require the lighted and hollowest Mould.”

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.