The Savannah morning news. (Savannah, Ga.) 1900-current, 1901-07-15
SuperphOsphate of Lime.


The history of agriculture is an ex-
ceedingly interesting story. 1t is no
new thing either and many things ap-
pertaining to it have been handed down
to us through a good many centuries.
writes Henry Stewart, in Practical
Farmer. Rotation of crops was prac-
ticed by the Romans, and over g.
600 years ago one of the most prom
inent of Roman writers on agriculture
in describing it said: Thus the land
rests, the produce being changed" So
the use of manures and of lime mong
others, was common in those ancient
times,and it has survived all these CEN
lures through it's useful effects alone,
the reasons for it's usefulness not hav-
ing been explained until a few years
ago-four or five only. And now we
are using a combination of lime and
phosphoric acid under the name of SUI
perphosphate of lime, and this has an
interesting story too.
All plants contain phosphoric acid
and lime in the form of phosphate of
lime. This element of plants goes to
form the bones of animals, the bones
consisting of about one-ha phosphate
of lime. Many years ago, by the mere
accident of growing a very fine crop
of wheat on a field in Sweden, where
many years before a battle was fought
the value of bones as a fertilizer was
discovered. Then the world was
ransacked for bones to use for this
purpose. For many years the supply
was obtained from the great African
desert, Sahara, all over which the
bones of men and animals which had
persisted of heat and thirst, We're gath
cred and ground and the bone dust
was sown on the wheat fields as fer
tilier, but why this was useful to the
wheat was not known for some years
after. AS soon as the secret was dis
covered the process of dissolVing the
bones in sulphuric acid was used to
make the phosphate of lime more SOL
uble and more Immediately available.
This result depended on the change of
the form of the phosphate into a com
bination of one part of the lime with
one part of the phosphoric acid, called
a phosphate of lime, or one-lime
phosphate, instead of three-li lime
y. osphate, which is the natural form
OF the compound and is only slowly
soluble. This popularity of the super
phosphate or compound having an ex-
cess OF phosphoric acid is very import
ant and should be fully understood by
every farmer who uses the fertilizer.
and doubtless this includes a majority
of readers of the p. F. For while the
fertilizer in this condition is soluble in
the soil and is thus at once available
for the crops, in it's natural form, phos-
phate of lime, which has three parts
of lime in IL. Is insoluble and is thus
not available as a fertilizer, and this
fact connects its use with the use of
ime as a fertilizer. For IL a farmer
lines his land in the fall when the
wheat In sown, and then in the spring.
~ worse gtfll In tho fall ngag aanar.
phospG ate, this soluble phosphate at
once combines with the lime and be-
comes the natural three-lime phos-
phate, which is insoluble, and, of
course. has no apparent effect on the
crop.
Thus the farmer who uses lime
should not use superphosphate within
the same year. and. indeed. IL is not
necessary 10 do so, for O. effect OF
line Is 70 make all other mineral ele-
ments available by its effect IN dis
solving the silica. by which potash.
magncsia and phosphoric acid are held
In combination. and thus IL sets free
otherwise inert phosnhoric acid. II had
once been the habit Of farmers who
called themselves practical farmers, 20
think dispnrngingly ~ what t'ey
called scientific farmers. There may
be- few remaining ~ such persons.
bat they are happily few and far be-
tween fnr the very great majority ~
cultiyufnra ~ the coil now feel and
know that there A. n0f "a farmer living
"a h0 can AFFORD 90 ignore me science ~
t.e arr Of agriculture any more than
other practical workers ~ nil kinds
a no end that 40 know che reasons o.
things which belong % their Industry
b. an amhTinn help a. them, lust az
the bright fan ~ help ~ ma ones