In Dr. _Woodward_’s Case, upon his Hypothesis, the Three Proportions of
Seeds, _viz._ Barley, Oats, and Pease, might be sown all together in
the same Acre of Ground, the same Year, and make Three as good Crops as
if sown singly in Three successive Years, and his Two Crops of Wheat
in one Year likewise. But every Farmer can tell, that these Three
Proportions of Seed would not yield half the Crop together, as one
would do single; and would scarce produce more than to shew what Grains
were sown, and which, of the Sorts were the strongest and the most able
Robber.
Though this Failure would, in Truth, be from no other Cause than want
of the sufficient Quantity of Food, which those Three Crops required;
yet, perhaps, the Doctor might think, that all Three Crops might
succeed together very well, taking each its proper Nourishment, were it
not for want of Room, Air, and Sun.
I have been credibly inform’d, that on One Perch of Ground there has
grown a Bushel of Corn, which is Twenty Quarters to an Acre. Mr.
_Houghton_ relates Twenty-six, and even Thirty Quarters, of Wheat on
One Acre. There have certainly grown Twelve Quarters of Barley to an
Acre, throughout a whole Field: Therefore, unless a Crop exceed the
least of these, or indeed the greatest of them (if the Relation be
true), a Crop cannot fail for want of Room; for one Acre (be it of what
Nature it will, as to the Soil of it) must have as much room for a Crop
to grow on, as any other Acre.
Then there was room for all Dr. _Woodward_’s Three Crops together, to
produce as much as Three common Crops do. Yet all these together will
scarce yield one Quarter of Corn, tho’ there is room, at least, for
Twelve.
The same _Air_ and _Sun_ that had Room to do their Office to Mr.
_Houghton_’s Acre, why should they not have Room to do the same to
Doctor _Woodward_’s Acre, when the Three Crops growing on it at once,
through pretty good ones, might require less Room than Mr. _Houghton_’s
Crop did?
I perceive that those Authors, who explain _Vegetation_, by saying
the Earth imbibes certain Qualities from the Air, and by specific
Qualities, and the like, do also lay a great Stress upon the
_perpendicular_ Growth of _Vegetables_; seeming to fansy there is
little else necessary to a good Crop, but Room.
Mr. _Bradley_, in his Arguments concerning the Value of an Hill, does
implicitly say as much.
But if they would but consider the Diameters of the Stems, with the
Measure of the Surface of an Acre, they would be convinced, that many,
even of Mr. _Houghton_’s Crops, might stand in a perpendicular Posture
upon an Acre, and Room be left.
One true Cause of a Crop’s failing, is want of a Quantity of Food to
maintain the Quantity of Vegetables, which the Food should nourish.
When the Quantity of Food which is sufficient for another Species (that
requires less), but not for that which last grew, to grow again the
next Year, then that other is beneficial to be planted after it.
The Second true Cause is from the Constitution of Plants; some require
more Food than others, and some are of a stronger Make, and better able
to penetrate the Earth, and forage for themselves.
Therefore Oats may succeed a Crop of Wheat on strong Land, with once
plowing, when Barley will not; because Barley is not so well able to
penetrate as Oats, or Beans, or Pease, are.
So a Pear-tree may succeed a Plum-tree, when another Plum-tree cannot;
because a Pear is a much stronger Tree, and grows to a much greater
Bulk; so inclined to be a Giant, that ’tis hard to make it a Dwarf; and
will penetrate and force its Way thro’ the untill’d Earth, where the
other cannot; being of a weaker and less robust Constitution, not so
well able to shift for itself.
The Pear could penetrate Pores, that the other could not. Mr. _Evelyn_
says, in his Discourse of Forest-trees, ‘That a Pear will strike Root
thro’ the roughest and most impenetrable Rocks and Clifts of Stone
itself.’ He says likewise, in his _Pomona_, ‘That Pears will thrive
where neither Apple or other Fruit could in Appearance be expected.’
I can scarce think, that a large Plant takes in larger Particles than
a small one, for its Nourishment: If it did, I can’t believe, that the
Thyme could have starv’d the Apricot-tree; it must have left the larger
Particles of Food for that Tree, which probably would have sufficed
to keep it alive: I rather think, that great and small Plants are
sustain’d by the same minute Particles; for, as the fine Particles of
Oats will nourish an Ox, so they will nourish a Tom-tit, or a Mite.
Some Plants are of an hotter Constitution, and have a quicker
Digestion, like Cormorants or Pigeons, devouring more greedily, and
a greater Quantity of Food, than those of a colder Temperature, of
equal Bulk, whose Sap, having a more languid Motion, in proportion
to the less Degree of Heat in it, sends off fewer Recrements; and
therefore a less Supply of Food is required in their room. This may
make some Difference in the one’s succeeding the other; because the
hot-constitution’d leaves not enough for its own Species to succeed
again, but leaves enough for a Species of a colder Constitution to
succeed it.
But the Third and chiefest Cause of the Benefit of changing Sorts is
Quantity of Tillage, in proportion to which the Food will be produced.
The true Cause why Wheat is not (especially on any strong Soil) to be
sown immediately after Wheat, is, That the first Wheat standing almost
a Year on the Ground, by which it must grow harder; and Wheat Seed-time
being soon after Harvest in _England_, there is not Space of Time to
till the Land so much as a second Crop of Wheat requires.
Tho’ sometimes in poorer Land, that is lighter, Wheat has succeeded
Wheat with tolerable Success; when I have seen, on very rich strong
Land, the first Crop lost by being much too big, and one following it
immediately, quite lost by the Poorness of it, and not worth cutting.
This was enough to satisfy, that the Tillage which was so much easier
perform’d in less Time, sufficed for the light Land, but not for the
strong: and, if the strong Land could have been brought into as good
Tilth as the light (like as in the new Husbandry it may), it would have
produced a much better second Crop than the light Land did.
From all that has been said, these may be laid down as Maxims; _viz._
That the same Quantity of Tillage will produce the same Quantity of
Food in the same Land[209]; and that the same Quantity of Food will
maintain the same Quantity of Vegetables.
[209] And _cæteris paribus_; for when the Land has been more
exhausted, more Tillage (or Dung) or Rest will be required to
produce the same Quantity of Food, than when the Land hath been
less exhausted. By Tillage is here meant, not only the Number of
Plowings, but the Degree of Division or Pulveration of the Soil;
or, if perchance the Soil is extraordinary much exhausted by many
Crops, without proper Tillage between them, the greater Degree of
Pulveration, by Plowing or Dung (which is only a _Succedaneum_ of
Tillage), and also a longer Time of Exposure, may be necessary to
counterpoise that extraordinary Exhaustion.
’Tis seen, that the same Sort of Weeds, which once come naturally in
a Soil, if suffer’d to grow, will always prosper in proportion to the
Tillage and Manure bestow’d upon it, without any Change. And so are all
manner of Plants, that have been yet try’d by the new Husbandry, seen
to do.
A Vineyard, if not tilled, will soon decay, even in rich Ground, as may
be seen in those in _France_, lying intermingled as our Lands do in
common Fields. Those Lands of Vines, which by reason of some Law-suit
depending about the Property of them, or otherwise, lie a Year or two
untilled, produce no Grapes, send out no Shoots hardly: the Leaves look
yellow, and seem dead, in Comparison of those on each Side of them;
which, being tilled, are full of Fruit, send out an hundred times more
Wood, and their Leaves are large and flourishing; and continue to do
the same annually for Ages, if the Plough or Hoe do not neglect them.
No Change of Sorts is needful in them, if the same annual Quantity of
Tillage (which appears to provide the same annual Quantity of Food) be
continued to the Vines.
But what in the Vineyards proves this Thesis most fully is, That where
they constantly till the low Vines with the Plough, which is almost
the same with the Hoe-plough, the Stems are planted about Four Feet
asunder, chequerwise; so that they plow them Four ways. When any of
these Plants happen to die, new ones are immediately planted in their
room, and exactly in the Points or Angles where the other have rotted;
else, if planted out of those Angles, they would stand in the Way of
the Plough: These young Vines, I say, so planted in the very Graves,
as it were, of their Predecessors, grow, thrive, and prosper well,
the Soil being thus constantly tilled: And if a Plum-tree, or any
other Plant, had such Tillage, it might as well succeed one of its own
Species, as those Vines do.
’Tis observed, that White-thorns will not prosper, set in the Gaps
of a White thorn Hedge: But I have seen the Banks of such Gaps dug
and thrown down one Summer, and made up again, and White-thorns there
replanted the following Winter, with good Success.
But note, That the annual plowing the Vines is more beneficial than the
one Summer Tillage of the Banks, the Vines having it repeated to them
yearly.
I have, by Experience and Observation, found it to be a Rule, That long
Tap-rooted Plants, as Clover and St. Foin, will not succeed immediately
after those of their own or any other Species of long Tap-roots,
so well as after horizontal-rooted Plants; but, on the contrary,
horizontal will succeed those Tap-roots as well or better than they
will succeed horizontal.
I confess, this Observation did, for a great while, cheat me into the
common Belief, That different Species of Plants feed on different Food;
till I was delivered from that Error, by taking Notice, that those
Tap-roots would thrive exceedingly well after Turneps, which have also
pretty long Tap-roots, though Turneps never thrive well immediately
after Clover[210], or St. Foin: I found the true Cause of this
Exception to that Rule to be chiefly the different Tillage[211].
[210] But when Clover has been fed by Cattle, the Ground being
good, and well tilled, Turneps may thrive immediately after Clover:
Therefore this is an Exception to the general Rule.
[211] Very mellow rich Land is so full of vegetable Food, that ’tis
an Exception to most Rules; and therefore I speak not of that.
Land must be well tilled for Turneps, which also are commonly hoed;
they stand scarce ever above Three-quarters of a Year, and are then fed
on the Ground; and then the succeeding Crop of Corn has, by that means,
the Benefit of twice as much Tillage from the Hoe, as otherwise would
be given to it; and the Broad Clover, or St. Foin, sown with the Corn
(if the Corn be not so big as to kill it), will enjoy, in its Turn, a
Proportion of the extraordinary Tillage, and of the Dung of Cattle,
which feed the Turneps, and thrive accordingly: But Broad Clover and
St. Foin, being perennial Plants, stand on the Ground so long, that it
lies several Years untilled; so that Turneps, sown immediately after
these, do fail, for want of their due Tillage, for which there is
not sufficient time, by plowing often enough; because, by the common
Ploughs, it requires Two or Three Years to make it fine enough for
Turneps, or for a Repetition of Clover, or St. Foin, in strong or
swerdy Land.
Another Reason why any Crop succeeds well after Turneps (and besides
their being spent on the Ground where they grow) is their cold
Constitution, by which they are maintained with less Food than another
Plant of the same Bulk.
The _Parenchyma_, or fleshy Part of a Turnep, consisting of a watry
Substance, which cools the Vessels, whereby the Sap’s Motion is very
slow, in proportion to the very low Degree of Heat it has, and sends
off its Recrements in the same Proportion likewise; and therefore
requires the less of the terrene Nourishment to supply those Recrements.
This is seen, when a Bushel of Turneps, mixed with a Quantity of
Wheaten Flour, is made into Bread, and well baked: This Bushel of
Turneps gives but few Ounces Increase in Weight, more than the same
Quantity of Wheaten Flour made into Bread, and baked without any
Turneps. This shews there is in a Turnep very little Earth (which is
the most permanent Substance of a Plant); the Oven discharges in Vapour
near all but the largest Vessels: Its earthly Substance being so small,
is a Proof ’tis maintained by a small Quantity of Earth: and, upon
that Account also, of less Damage to the next Crop than another Plant
would be, which required more of the solid Nourishment to constitute
its firmer Body, as a Charlock does; for when a Charlock comes up,
contiguous to, and at the same time with a Turnep, it does so rob the
Turnep, that it attains not to be of the Weight of Five Ounces; when
a single Turnep, having no more Scope of Ground, and, in all respects
(but the Vicinity of the Charlock), equal, weighs Five Pounds, yet that
Charlock does not weigh One Pound.
And where Three Turneps coming up, and growing thus contiguous, will
weigh Four Pounds; a Charlock joined with Two or Three Turneps, all
together, will be less than one Pound, upon no less Space of Ground.
This Observation cannot be made, except where Turneps are drilled in
Rows; and there ’tis easy to demonstrate, that a Charlock, during the
time of its short Life, draws much more Earth than a Turnep of equal
Bulk, from an equal Quantity of Ground[212].
[212] ’Tis certain that Turneps, when they stand for Seed, suck and
impoverish the Ground exceedingly: For though they are of a cold
Constitution, and consequently consume less Food than Plants of an
hotter Constitution, and of the same Bulk; yet these Seed-turneps
being of so vast a Bulk, as sometimes Eighty Quarters of their Roots
grow on an Acre, and their Stalks have been measured Seven Feet high,
and their Roots having continued at near their full Bigness for
about Ten Months together, and then carried off, they drain the Land
more than a Crop of other Vegetables of a less Bulk, and an hotter
Constitution, and which live a less time; or than Wheat, which,
though it lives as long, is very small, except in the Four last
Months.
The true Cause why Clover and St. Foin do not succeed so well after
their own respective Species, or that of each other, as Corn, _&c._
can, is, that they take great Part of their Nourishment from below the
Plough’s Reach, so as that under Earth cannot be tilled deep enough,
but the upper Part may be tilled deep enough for the horizontal Roots
of Corn, _&c._ towards which, the Rotting of the Clover and St. Foin
Roots, when cut off by the Plough, do not a little contribute[213];
And there’s no doubt but that, if the under Earth could be as well
tilled for the Tap-roots, as the upper Earth is for the horizontal, the
Tap-roots would succeed one another as well as the horizontal would
succeed them, or those of their own Species, or as the Tap-roots do the
horizontal.
[213] That the Rotting of vegetable Roots in the Ground doth ferment
therein, and improve it for horizontal-rooted Plants, I am convinced
by an Accident; _viz._ My Man had plowed off the Earth close to the
Rows in a Field of extraordinary large Turneps designed for Seed.
This Earth was neglected to be thrown back to the Rows, until a
severe Frost in the Winter came, and killed the Turneps; upon which,
in the Spring, the Field was sown with Barley upon the Level, with
only _once_ plowing, and that cross-ways of the Rows. The Turneps
had stood so wide asunder, that the Spot whereon each had rotted,
appeared like the Spot whereon an Horse had urined in till’d Ground,
and was of a deeper Colour, and much higher, than the Barley that
grew round those Spots; and yet none of it was poor. As the Roots
of Clover, and St. Foin, are very much less; yet the greater Number
rotting in plowed Ground must be of great Use to a following Crop of
Corn.
I will here relate Two Examples of this in St. Foin: The one is,
That a Field of Twenty-five Acres drilled with St. Foin, except
Three Acres in the Middle of it, which was, at the same time, sown
with Hop-Clover; after Eight Years the whole Field was plowed up by
a Tenant, and sown with Corn: The St. Foin had been mowed yearly,
as the Hop-Clover was not mowed at all, but fed by Horses teddered
(or staked) thereon the First and Second Years; and after that had
nothing on it but poor natural Grass.
The whole Field was managed alike, when plowed up; but the Three
Acres produced visibly worse Crops of Corn than the rest all round
it, which had produced St. Foin.
The other Example or Instance was, Where an Acre, Part of a Field,
was, by a Fancy, drilled with St. Foin in single Rows, about
Thirty-three Inches asunder, but was never hoed: After Seven Years
it was plowed up with the rest of the Field cross the Rows, and sown
with Oats upon the Back Three Months after plowing. These Rows were
as visible in the Oats, as if the St. Foin had been still remaining
there: The Oats in the Rows where the St. Foin had been, looked of
a deep green flourishing Colour, at first coming up, and until they
were about half a Foot high, and the Spaces between them looked
yellowish; but afterwards the Difference of their Colour disappeared,
all the Crop being very good. Upon this I imputed it to the Rotting
of the Roots, which by their Singleness were very large; and when the
different Colours disappeared, I suppose the Roots of all the Oats
had reached to the Benefit of the rotted Roots, which might also be
then spread farther into the Spaces; and I doubt not but that the
Rotting of Broad Clover-roots has the same Effect as of St. Foin, for
manuring of Land, especially when the Roots are large.
Some have objected against this Opinion, and say the Effect was
rather to be imputed to the Rows of St. Foin shadowing the Earth
under them, or else from their keeping the Earth under them free from
Couch-grass, of which the Intervals were full: But I think it more
probable, that the Couch-grass, having very long horizontal Roots,
might draw Nourishment from the Earth under the Rows, and from the
Intervals equally.
And as to the Shadow of the Rows, tho’, for the First and Second
Years, the St. Foin Plants were very large; yet, being afterwards,
for Five or Six Years, until plowed up, constantly fed by Cattle, and
being more sweet, was eaten very low, whilst the Couch-grass remained
intire in the Intervals, and shadowed them more than the Earth of the
Rows was shadowed by the St. Foin: Besides, the rotten Turneps, which
were freed from both these Objections, had the same Effect on the
Barley, as the St. Foin had on the Oats.
The under Earth, in some time, is replenished by what the Rains leave,
when they sink through it; and then Tap-rooted Plants may be there
nourished again, tho’ the upper Earth be drained by the Corn; so that
no Change is so beneficial, as that betwixt Tap-rooted Plants, and
those which have only horizontal ones. The former are provided for by
Rains, though not so speedily as the latter are by Tillage and Hoeing.
Pastures require no Change of Herbs; because they have annually the
same Supply of Food from the Dunging of Cattle that feed on them, and
from the Benefit of the Atmosphere.
Meadows hold out without Change of Species of Grass, tho’ a Crop be
carried off every Year; the Richness of that Soil, with the Help of the
Atmosphere, Dung of Cattle in feeding the After-Crop, or else Flooding,
from the overflowing of some River, some, or all of which, supply the
Place of the Plough to a Meadow.
Woods also hold out beyond Memory or Tradition, without changing Sorts
of Trees; and this by the Leaves, and perhaps old Wood, rotting on the
Soil annually, which operate as a Manure; because, as has been said,
Earth which has once passed any Vessels, is so changed, that, for a
long time after, it does not retain its Homogeneity[214] so much as
to mix with pure Earth, without fermenting; and by the Descent of the
Atmosphere, the Trees shadowing the Soil, to prevent the Re-ascent
of what that brings down; all this, resembling Tillage, continually
divides the Soil, and renews the Food equal to the Consumption of it
made by the Wood.
[214] Not that the Particles of Earth are strictly homogeneous, but
that they are much less heterogeneous, before they are altered by
Vessels, than afterwards.
And the last Argument I shall attempt to bring for Confirmation of
all I have advanced, is that which proves both the Truth and Use of
the rest; _viz._ That when any Sort of Vegetable, by the due Degrees
of Heat and Moisture it requires, is agreeable to a Soil, it may, by
the new Horse-hoeing Husbandry, be continued without ever changing the
Species.