Clarksville chronicle. (Clarksville, Tenn.) 1857-1865, 1858-03-12
ACRICUL

TUE RoTATIoN OF CRops.--The practi-
cal good Of the rotation Of crops is we'll
known, but the philosephic reasons, though
much written about have not been yet full J
~ and satisfactorily explained
There are TIVE theories. The fret or cr-
eretory theory Hccounts for the phenomena
thus; One crop docs better where it fol-
lows onother, because every plant leaves I
in the soil certain excretory matters, that
are not friendly TO other plants of its own
species; while they are appropriate food
for different plants Plants seem endow
ed with something Of the same instinct as
animals, and avoid their own feces or
the dead matter thrown from their own
bark and roots. Until these are decompo
sed, and removed from the earth by other
plants, or BY the gradual effects Of decom
position, the crop cannot be advantageous
" planted in the same soil. Hence in raj
sing dubious flowers, like the hyacinth
which grows in water, there must be fire.
quent change of the water, in order to re-
move the excretory matter thrown off from
the roots of the plant. The same foul wa
ter, however, is found TO be good stimu
liant to other kinds of plants, and will some
water It is also a well known fact that
nurserymen find it difficult to make sec
ond crop Of young apple trees grow, where
they have been grown before. Even with
heavy manuring, they find it better policy
to take piece Of ground that has been oc-
cupied with some other crop. Ifthere are
exceptions to the advantages ofrotation, as
there seems to be in the case Of the onion,
and some other garden crops, it is in case
of grass feeders, where a great deal of me-
nure is used, which, by its fermentation
in the soil, decomposes the excretory mat
ter of the crops of the preceding sea-
son. The onion crop is almost always
heavily MANFRED, and dressed with ashes,
which furnish lime and potash, two power
full alkalies, that act with great rapidity
upon all vegetable fibre. SO much for the
theory.
The second theory may be stated thus
Each plant absorbs some essential constit-
uent from the soil, which in time, becomes
exhausted. If, for instance, the wheat
plant demand phosphate of lime, and there
is but small quantity in the soil, it fails
to be perfectly developed when it cannot
find full supply of this mineral. 1t must
be restored by the application of manure
or by fallow, or the growth of some 9TH
er crop that does not require much phos-
plate of lime for its perfect developments.
Another example is frequently given Of
root crops which usually contain consid-
cradle quantities of alkalies. This theory
supposes a root crop to exhaust the ready
formed alkalies in soil, and that alkaline
manure must be added or change of crops
be made, while a further disintegration OF
the soil is setting at liberty new supplies
of alkalies.
We think there is some truth in both
of the theories as above stated, but that
neither Of them, and especially not the sec.
ond one, will fully account for the advan
tages of rotation.
1t is probably the exhaustion of the or.
ganic or vegetable matters in the soil, more
by one crop than another, that chiefly ha!
todo with the benefit of change of crop
A rotation is not only demanded for the
sake Of furnishing new pasture GROUND
for the roots of plants, but to prevent the
increase of predatory grubs and insects
The instinct of these creatures leads then
10 deposite their eggs where the young
when Matched, will find their favorte fooC
in readiness. The intelligence of mar
circumvents this instinct, by changing thu
crop, and cutting of the supplies of tn,
young grub.
The light lands of England are com
monty cultivated under a four or fv
course system. The four courses begin
with fallow ground, MANFRED LIST year
turnips fed off; I'd, oats or barley 3D.
grass seed; 4th, wheat. The fifth cours
is: turnips; oats or barley; clover; peas
wheat
On heavy clays the rotation is usual
fallow, with manure wheat beans; whea
MANFRED; clover; oats or wheat
There is, perhaps, no point in good hus
bandry that calls for the examination @
American farmers more urgently than this
1t has wrought wonders in England, an
there can be little doubt that it would wor
quite as favorable change in our own ae
rioulture. 1t is common fault wit
us to keep our land too long in one croI
Grass, not uufrequently, occupies the sam
held for eight or ten years, until less tina
half ton of hay is cut to the acre.
We have seen a large tract of exceler
light land made barren, by cropping wit
rye in alternate years. The same resu
follows with wheat and buckwheat. No
is the time for farmers to mature the
plans fer the coming season, and to ente
upon judieious rotation of crops,