Year: 1861




The practice Of agriculture consists of series
OF operations, by which We endeavor to raise
from the land the most valuable produce it is
capable Of yielding, with as little cost as pos
sible, and with the least injury to the soil. An
ignorant person might manage to draw from
the land very heavy crops Of corn for short
time, and In doing so he might seriously dam
age the property. Whereas, another, possess
Ing practical knowledge Of good systems
might succeed in realizing the same value Of
produce without injuring the character Of the
land. 1t has therefore been accepted as an
established principle, that judiciOus success
sion OF crops is advantageous for aiding the
farmer to produce the best crops he can with
the least detriment to the land. Experience
proves to every observant person that, under
our ordinary practice, the repeated growth of
any crop upon the same piece produces grad
ual decrease in the quantity which the land is
capable of yielding. This takes place more
rapidly in some soils apd under some crops
than others, but the same fact stands out in
all the light of an accepted truth. Now to
what causes can we trace this! The only two
changes which the plant can have produced
in the soil are the addition of noxious matter
and the abstraction Of fertilizing matter. 1t
mss been well argued that plant, during the
period of its growth having received from
various powers its supplies of food, appro-
priated for the purposes of its own develop
ment such matter as it required, and elected
oy IT'S roots, as excrementitiOus matter, that
which was of no further use. 1t was further
believed, that as the soil became more and
more fully charged with such excrementitious
matter, the growth of the crop became less
luxurisnt because Of the soil being charged
with that which was believed net only to be
worthless for promoting the plants growth,
but positively injurious. In the case Of ani-
mails this is observed very plainly; and the
whi
their various excrements, shows the means
which Nature has planted in each to lead
them to avoid that which would be, not only
useless, but really injurious. This expIana-
ton was very generally accepted for many
years, end it was very reasonable mode of
explaining the observations of practice. 1t
appeared to be corroborGted by the fact that
after the soil had been exposed to the air by
the process of cultivation, the land became
"oweetenel," as they termed it, and then was
again ready for the production Of the same
crops; whereas, if the land were kept as much
as possible from the atmosphere, then the
crop still failed to be productive. Although
this explanation appeared very simple, yet,
being destitute Of satisfactory proof il onsy
held this position until its successor came into
notice.


The claims of its rival were based upon the
exhaustion Of the land, and its principles are
simple. Every crop removed from the land
taxes from 1t certain quantity Of minersI
matter which the land had yielded in its
growth. Every successive crop Of the same
plant having removed similar materials, the
proportion of those ingredients of the soil
which remained was thus gradually reduced
by every crop. If the soil were rich, il could
withstand the attack for a longer period Of
time than II II were poor in quality; and this
fact alone leads US TO see the cause. If we
have u soil rich in the inorganic elements
required by the crop, such a soil would bear a
longer succession; but, if deficient in these
mineral matters, more speedy failure Of the
crop is the result


Should a soil possess some of the ingredients
IN abundance, whilst others which are essen
tlal TO the growth Of the crop are deficient,
the preductlveness Of the soil will be regu-
lated by the latter. Thus land may be ex-
hausted OF certain ingredients which the crop
requires, and consequently becomes incapable
Of producing it in Iuxuriance, or even in
ramunerative degree, whilstit may still possess
all the other ingredients in abundance. For
crops, therefore, which relied upon those ma
teTiais yet remaining in the land, it would still
be fertile or prOductive.


This explanation has been very generally
accepted as substitute for the excrementi-
tiOus principle before named; and there is
much truth in the argument based upon the
exhaustion of the soil Still we are far from
being disposed to consider this as fully explain
ing the principles which are embodied in this
interesting subject. We must ever remember
that, whilst we seek truth, we must not rest
upon few fragments, although they may be
In themselves perfectly correct that in the
functions of vegetable life many principles are
involved. Let us prize each as we discover
them, and await with patience ard persevering
industry until we have gained those that re-
main. These will ultimately iOvetail in with
those we already know, and render the series
complete. Whilst, therefore, we cannot con-
sider that the necessity for judicious success
SION OF crops which will favor the fer tility in
the land, depends solely upon the exnaustion
of the mineral ingredients of the soil, yet we
are fully justified in stating the fact that has
a powerful influence upon the result, as is
worthy of very careful consideration.


In another page of this magazine we have
inserted table, which will give the reader a
clear view of the mineral matter which our
crops contain. As the soil is the only source
from whrcn these materials can be procured, it
will be evident that without due considera-
ton OF these facts, We cannot have safe infOr-
nation to guide US, either as to the best sue
cession of crops, or enable US to com Densate the
natural deficiency so produced in our soils, by
the aid of manures
w. There is a remarkable difference in the food
required by different crops. For example, our
corn crops take from IS lbs to l4O lbs Of silica
per acre, but other crops from 8 lbs. to 20 lbs.
whilst the root crops make a demand upon the
soil for the alkalies potash and soda) far in
excess Of that required by the corn. In like
manner, We observe other equally important
and singular differences in the demands made
upon the soil. This variation in some measure
explains the adoption of certain rotations,
whereby the crops are placed in that order Of
succession which will distribute the demands
as much as possible, instead of allowing them
to concentrate too much at any period of the
course. It must not be supposed that the
credit arising from the adoption of our estab-
ished rotations belongs to those who have dis
covered these principles; for such is not the
case. Successful practice having given remu-
nerative proof Of success, led to such an estab-
lished order; and afterwards by the assist ance
Of scientific investigators we discovered some
of the causes for this method. Practice showed
that to obtain success certain crops had to be
distributed through the course, and separated
from each other, whilst other crops answered
well in immediate succession. We have so far
drawn attention 10 the data by which these
singular facts can be explained, and shall next
more fully elucidate this most interesting
branch Of rural economy.-Farmer' MagG-
zrne (Lond0R)


MINE OF OPALs "A valuable mine Of opals has