The St. Cloud journal. [volume] (St. Cloud, Minn.) 1866-1876, 1871-11-02
ROTATION OF CROPS,

s'il, which, when the plants arr burned,
constitute their ashes. The amount
and nature Of the food they exist on is
thus ascer,aircd. IF cereal crups are
raised frequently off the same SOIL,
without anything being restored BY
manuring, the acerable produc, gradu-
ally diminishes, and after time it is
found that the produce in seed, which
was originally twelve to fifteen times
the amount OF what Was sown, is re-
duoed to Eve, and sometimcs to three
times the amount. The fertility Of the
soil is gradually diminished by tho rep
itition Of crops of the same klnd, be-.
cause they abstract annually a certain
class Of its ingredients. Tho exhaust
ing power is exercised by all crops, but
varies much. 1t may be said that every
plant diminishes the fertility OF the
soil in the spot Gu which it is grown,
unless some portion Of it IS returned to
the ground.
1t Is better to prevent the exhaust
ion of the soil than 10 endeavor to cure
1t. 1t is sometimes difficult to discov.
or what the land really requires. The
best method Of preventing the exhaust.
ion is BY introducing a judicious rota-
ton Of crops, which ore unlike one au-
other, and consequently do not require
exactly che sane kind OF Ingredients
to sustain their growth. In adopting
such rotation, we copy nature. In
the natural forest, many generations Of
broad.leaved trees live aud die, and sue.
coed others but the time comes at last
when general pestilence seems to as
sail them all. Their tops droop and
visher, their branches fall of, their
trunks rot; they die out, and mar
row leaved race succeeds them. THIS
race again has its term to existence,
which lasts perhaps several centuries ;
but death seizes i: TOO, and the broad
leaves OF the beech, the maple, tho ash,
aud the oak again cheer the eye. 1t is
30 10 the broad meadow the grass
changes, aud new varieties succeed
othes>ss tho field, increase in age.
The alienation Of crops, therefore,
possesses something of the dignity Of
. natural law; and man is evidently
right when he initiates, on asmaIl scale
some Of tho grand processes of nature.
Bot upon what do The good effects Of
rotation depend Why do the broad
leaves alternate With the narrow in the
ancient forest? Why does the grasses
change in the meadows aud pastures :?
Why does the farmer obtain a larger
produce, aud !or greater number OF
years by growing unlike crops alternate
ly, than By continuing year after year
to grow the same? The reason is not
merely that one crop carries off more,
and another crop less, Of the ingrcdi-
euts which crops derive from tho soil !;
but that one carries off more of one
thing, another crop moro Of another
Grain carries of phosphorus, straw
silica, aud the. bulk alkaline matter.
After several successful crops of the
same kind, tie surface soil through
which the roots are spread, becomes 50
devoid OF those subst ,nces which tho
crop specially requires, taat the plant
cannot extract tho necessary substance.
The roots do their best; they collect
As diligently as they can, but tie
supply Of food gives out before the
plant arrives at maturity. In the case
Of a grain crop, the first effect of a
scarcity, say Of pbosrhorio acid, is to
make The ear smaller, aud the number
OF grains less; the next, to continue
growth until frost arrests vegetation.
But suppose VIC alternate cereal crop,
which requires much phosphorus, with
grass CT clover crop, which requires
much silica, or root crop, to which
much alkaline matter is necessary, then
the one crop would live upon and re-
move what the others had left in great
abundance. Instead Of robbing the soil
every year Of the same substances, we
should be exbausting it more equally
Of all, and no should DO able, for double
the time At least, to crop it without the
risk of iss ccysiog entirely to give US
profitable return. We should gradually
work up, also every available substance
10 the so'l, whether such as are na,ur
ally present in it CT such os We have
added in the form Of manure.
What is true Of the simple aIterna-
ton Of cereal crop with green crop,
is more true still Of longer aud more
complicated rotation. The greater the
variety of crops we grow, and the
longer the iotersal betwcen crops of
the same kind, the more perfectly do
We avail ourselves of the benefits which
an obedience to the suggestions of this
principle 10 fitted to confer upon us.
It is true that no rotation, however
judieious, will alone prevent the land
rom becoming exhausted. Nothing
but regular and suitable manuriug will
Do this unless there be in the decayipg
fragment tf rock mixed with the soil,
or in substances brought down from
higher grounds, on 10 tho nature If
the rain and snow that fall upon the
ground, some unusual and perennial
source Of those substances which the
crops annually require. Alternating
green crops With cereals has very ben:
e6eiai effect by keeping land free from
those weeds which ripen and shed
their seeds among grass crons and