The Brookhaven leader. [volume] (Brookhaven, Miss.) 1883-1891, 1888-11-15
CHEMICAL ANALYSIS.
IT'S UnreIIability When Applied to the 4
animation of Soil.


animation of soil.
It Is often thought that o chemical
examination Of epy soil will reveal the
true value of the ingredients contained
in 1t. Many, consequently. have the
idea that to analyze the soil chemically
is sufficient TO show what elements are
present and how much OF these ele-
ments can be utilized by the plant in
the process Of its growth. And further,
that be knowing the mineral constit.
uents of the matured plant and the total
amount Of these constituents extracted
by the crop, it will be an easy step to
ascertain what mineral fertilizers are
needed TO apply to the soil to make up
any deficiency caused by their absence
from the soil, or to make good what is
extracted by the crop.
Director H. B. Battle, OF the n. G.
L. s., says that the fsllacy of this rea.
sonlhg lies in the fact that d chemical
examination OF the soil, while it does
give the total quantity Of Its constitu'
ents, does not give the quantity avail
able to the plant, such as can be
utilized by the plant. This fact is all
important, fot there may be plant food
In abundance, in the soil, yet in such
a form that 1t is impossible for the
plant to derive any benefit from its
presence, though it may lie in intimate
contact With its numerous roots. Many
OF our ordinary teldspathic rocks con-
tain in every 100 pounds as many as 10
pounds of potash. Yet these 10 pounds
almost equivalent to 100 pounds Of
kainit-are in such an insoluble, I'M
available form, that they are absolute
ly unserviceable as plant food, unless
by some process of disintegration and
decomposition, they may become
changed to form which the plant can
take up.
The thorough chemical examination
will give the quantity Of potash pres
ent, and likewise the quantity of the
other chemical elements, but the sci
ence of chemistry has not yet devised
an exact method for determining the
proportion of these constituents, which
is available to the needs of the plant.
and which can be used by it in its
growth.
But does chemical analysis of the
soil, no matter with what exactness it
is carried out, show with sufficient ac-
curacy the contents of the soil? Can
we depend on its results to show with
definiteness what fertilizer to apply to
the soil to render it more productive?
For this distinct purpose the chemical
analysis, always so delicate and accu-
rate, is inadequate. A cubic foot OF
our average upland soil (from results
obtained at the station in the
pasO, weighs ITO pounds. An
acre of this soil, inches deep,
weighs 2,835,062 pounds. or a
fraction over l, All tons. Nine inches
are taken as an average depth reached
by plants roots; with cotton the tap
root grows even much lower than this.
The ordinary application of ammoni-
ated fertilizer is 200 to 800 pounds to
the acre. II this application of 500
pounds is Thoroughly mixed with the
soil, and an average sample obtained,
then by no chemical means, no matter
how delicate, can this ammoniated fer.
tilizer be detected, and yet this appli-
cation changes the yield from an UNI
productive to a productive one, and
draws the line between success and
failure. Not only can not 800 pounds
to the acre be detected by chemical
means, but it is also the case with SOC
pounds, with 1000 pounds, with one
ton, to the acre. We can see, there
fore, how little we can expect from a
chemical analysis of a soil.-Rurai
NeW Yorker.