Delaware gazette. [volume] (Delaware, Ohio) 1855-1886, 1858-03-05
Rotation of crOps.

The practical good OF rotation of crops 10
well known, but the pffilosoPhic reasons.
though much written about have not been
fully and satisfactorily explained.
There are two theories. The first or sr>
cretory theory accounts for the phenomena
thus One crop does better where it follows
another, because every plant leaves in the
soil certain excretory matters, that arc not
friendly to other plants of its own species;
while they are appropriate food for different
plants. Plants seem endowed with some
thing of the same instinct as animals, and
avoid their own f9ces or the dead matter
thrown from their own bark and roots. Un-
til these are decomposed, and removed from
the earth by other plants, or by gradual ef-
fects of decomposition, the same crop can
not be advantageously planted in the same.
soil. Hence in raising bulbous flowers, like
the hyacinth which grows in water, there
must be frequent change Of water. IN on
der TO remove the excretory matter throws
off from the roots of the plant. The same
foul water, however, is found to be q good
stimulant to other kinds of plants, and will
sometimes make them flourish better than
pure warer. 1t is also well known fast
that nurse rmen find il difficult 10 make a
| second crop of young apple trees grow
where they have been grown before. Even
with heavy mnnuring, they find it better pol
icy to take piece Of ground that has been
/ occupied with some other crop. II there
are exceptions to the advantage of rotation.
| as there seems to be in the case of the on
ion, and some other garden crops, il is in
case of gross feeders, where grest deal OF
manure is used which, by its fermentation in
the soil, de composes the excretory matter Uf
the crops of the proceeding season. The on
| ion crop is almost always heavily manured.
and dressed with ashes, which furnish lims
and potash, two powerful alkslies, that act
with great rnpidty upon all vegetable fiber.
| So much for this theory.
The second theory may be stated thus
Each plant absorbs some essential coBstitu-
ent from the soil, which, in time, becomss
exhausted. Ii, for instance, the whoa.
plant demands phosphate OF lime, and there
| is bu; small quantity in the soil, it fails 10
be perfectly developed when it cannot find
full supply of this mineral. 1t must be re-
stored 6y the application of manure or BY a
fallow, or the growth If some other crop
that does not require much phosphate d
lime for lis perfect development. Another
example is frequently given Of roots drops.
which usually contain considerable quanti-
ties of alkalies. This theory sUppOses 4
root crop to exhaust the ready formed aka
lies in soil, and that alkaline mauures must
be added or a change OF crops be made, while
a further disenegration Of the soil is setting
at liberty new supplies of ak allies.
We think there is some truth in both OF
the theories as above stated, but that neith-
er of them, and especially not the second
one, will fully account for the advantages Of
a rotation.
1t is probably the exhaustion Of the or
9anic or vegetable matters in the soil, more
by one crop than another, that chiefly has
to do with the benefit OF change of crops.
The main points in these theories were die
cussed in our MANURE articles In the last VOL
ume.
A rotation is not only demanded for the
sake OF furnishing a new pasture ground for
the roots of plants, but to prevent the ins
crease dip redatory grubs and insects. The iu-
stinct OF these wonderful creatures leads them
to deposit their eggs where the young, when
hatched, will find their fuvorite food in read
mess. The intelligence Of man circumvents
this instinct, by changing the crop, and cut
ting off The supplies of the young grub.
The light lands of England are common
ly cultivated under four or five course sys-
TEN. The four courses begins with fallow
ground, manured lst year, turnips fed on;
I'd, oats or barley; 81, grass seed; Ath'
wheat. The fifth course is: turnips; oats
or barley; clover; peas; wheat.
On heavy clAys the rotation is usually fall
low, with manure; wheat; peas; wheat ma
nured; clover; oats or wheat.
There is, perhaps, no point in good hus-
brndry that calls fo- the examination OF
American farmers more urgently than this.
, II has wrought wonders in England, aud
there can be httle doubt that il would work
} quite as favorable a change in our own agu-
) culture. It is common fault with US, %
| keep our land too long in one crop. Grass
, no, untrequently, occupies the same Geld Tor
3 eight or ten years, until less than half ton
Z of hay is cut to the acre.
, We have seen large tracts OF excellent
] light land made barren, by cropping with
G rye in alternate years. The same result tol'
6 lows with wheat snd buckwheat. Now i'
the time for farmers to mature their plane
for the coming season and TO enter upon
8 iudieiOus rotation OF sroP''
e 20.