The weekly Portage sentinel. [volume] (Ravenna, Ohio) 1854-1861, 1858-03-04
AHEMmd
ISRotatioh OfCrOps.

is well known, but the philOsodhic reasOns'
though much written about, have not yet
been fully and satisfactorily explained.
There are two theories. The frst or ex'
cretory theory accounts for the phenomena
+. thus: One crop does better where it ioi'
lows another, because every plant leaves in
The soil certain excretory matters, that are
not friendly to the other plants Of its own
species; while they are appropriate food for
different plsnts. Plants seem endowed with
something Of the same instinct as animals,
and avoid their own foees or the dead mat.
ter thrown from their own bark and roots.-
Until these ere decomposed, and removed
from the earth BY o'her plants, or BY the
gradual effects OF decomposition, the same
crop cannot be adyantogeously planted in
the same soil Hence in raising bulbous
flowers, like the hyacinth, which grows in
water, there must be a frequent change Of
the water, in order to remove the excretory
matter thrown of from the roots Of the
plant, tbs same foul water, however, is
found to be good stimulsnt to other kinds
Of plants, and win sometimes make them
flourish better than pure water. It is also
well known fact that nurssrymen find it
difficult 10 make second crop Of young ap
pie trsestgrow, whore they have been grown
before. Even with heavy manuring they
find il better policy to take piece of ground
that has been occupied with some other
crop. If there are exceptions to the advan.
tages of rotation, as there seems to be in
the case of the onion, and some other gard n
crops, it is in case Of gross feeders, where
great deal of manure is used, which, BY its
fermentation in the soil. decomposes the ex-
cretory matter Of the crops Of the preceding
year. The onion crop is almost always
heavily manured, and dressed with ashes,
which furnish lime and potash, two power
ful alkalies, that act wi h great rapidly upon
all vegetable fiber. So much for the
theory. .-aar' a'
The second theory may be stated thus:-
Each plant Absorbs some essential conStitu
ent from the soil, which, in time, becomes
exhausted. II, for instance, the wheat plant
demand phosphate Of lime, and there is but a
small quantity in the soil. il fails to be per.
fsetly 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 other crop that doeI
not require much phosphate of lime for it
perfect development. Another example il
frequently given ofroot crops, Which u'ualy
contain considerable quantities Of ukalies
This theory rupposes a root crop to exhaus
the ready formed alkolies in the soil, an,
that alkaline manures must be added or
change Of crops must be made, while a fur
ther disintsgration of the soil is setting a
liberty newly formed supplies Of alkalies.
We think there is some truth in both @
the theories as above stated, but that neithe
Of them, and especially not the second one
will fully account for the advantage Of th,
rotation.
1t is probably the exhaustion Of the organ
ic or vegetable matters in the soil, more By
ono crop than another, that chiefly has to do
with the benefit of change of crops. The
main points in these theories were discussed
in our articles on manure in last volume.
A rotation 10 not only demanded for ths
sake Of furnishing new pasture ground fol
the roots of plants, but to prevent the in
crease Of predatory grubs and insects. The
instinct of the wonderful creatures leads
them to deposit their eggs where the young
when hatched, will find their favorite food IN
readiness. The intelligence Of man circum
vents this instinct, by changing the crop
and cutting off the supplies Of the young
grub.
The light lands Of England are commonly
cultivated under four or Eve acre course
system. The four courses begins with fal.
low ground, manured frst year, turnips fed
of; second, oats or barley; third, grass
seed; fourth, wheat. The fifth course is:
turnips, oats or barley, clover, peas, wheat.
On heavy clays the rotation is usually fal.
low, with manu- z; wheat, beans, wheat ma.
nured, clover, oats or wheat.
There is, perhaps, no point of good hus.
bandry that call for the examination Of
American farmers more urgently than this.
1t has wrought wonders in England, and
there can be but little doubt that it would
work quite as favorable q change in our
own agriculture. 1t is common fault
with US. to keep our land tso long in one
crop. Grass, not unfrequently, occupies
the same field for eight or ten years in sue.
cession, until less than half ton of hay ID
cut to the acre.
We have seen large tracts Of excellent
light land made barren, by cropping with
rye in alternate years. The same result
follows with wheat aud buckwheat. Now
is the time for our farmers TO mature thai
plans for the coming season, and to ente
upon q judicious rotation Of crops Prairi
Farmer.