Vernon Parish Democrat. (Leesville, La.) 1917-193?, 1919-07-19

phate, n superphosphate of lime, raw
rock Phosphate, finely ground, IS mix
J ed with sulphuric acid. The chemica
change effected in this way renders
the phosphoric acid in the resulting
mixture soluble in water. Il is a well
known fact that, although the phos-
phoric acid in acid phosphate and in
mixed fertilizers made from it original
ly was soluble in water. a chemical
change takes place when these fertil-
izers are mixed with the soil.
The phosphoric acid "reverts" and
has tendency to go back to its orig
inal form. Reverted phosphoric
must be dissolved BY the soil agencies
before it is available to plants. The
only purpose, therefore, achieved by
the fertilizer manufacturer in treating
rock phosphate with sulphuric acid, is
the chemical decomposition of the
crude rock, which brings about such a
fine division of the particles that the
plant roots can assimilate the needed
phosphoric acid.
Is there any good reason for paying
fertilizer manufacturers to make phos-
phate available" with high priced sui
phuric acid, when the phosphate 50
treated will not stay in this condition
long enough to be used by plantsp
Soft phosphate is in the proper form.
1t needs no treatment with sulphuric
acid. 1t is easily acted upon by the
organic acids and made available by
the soil agencies. 1t cannot revert and
none of its plant food can be locked
up. If you have not been cultivating
legumes and must defer doing SO, and
your soil is deficient in nitrogen, or
ammonia, these elements can be sup
piled in the form of nitrate of soda,
but there is no good reason for buying
this plant food in expensive fertilizers
when you can produce it ON your own
farm, or get it as suggested above.
Speaking of the source Of phosphor-
us, DR.. Cyril G. Hopkins of the Univer-
sity of Illinois. the greatest living au-
thority on ground raw rock phosphate
as fertilizer. known in Europe as
well as in America for his research
work, scientist and also a practical
farmer, says there are many kinds of
fertilizing materials that contain phos-
phorus. One may cost ten times as
much as another so far as the phos-
phorus is concerned. One ton Of fine
ly ground phosphate contains $50
pounds of phosphorus; this ton may
be mixed with a ton of sulphuric acid
in the fertilizer factory and the two
tons Of so-called acid phosphate sold
to the farmer, or the fertilizer manu-
featured may mix the two tons Of acid
phosphate with two tons Of filler, con-
tanning little nitrogen and potassium,
and sell the same four tons of social
ed complete fertilizer, but the farm
er gets no more phosphorus in the four I
tons of complete fertilizer" than in
the one ton of natural phosphate.
am safe in saying that as a rule all
U. S. Demonstration and Experiment
Farms never buy the so-called COM
plete fertilizers" but do their own mix
ing, and grow green manures and turn
them under, that is cowpeas, soy beans,
and any other of the legume family
of peas. beans or vetches, clovers, etc.
Growing green manures and turning
them under and using lime or, as
would proper, soft phosphates with the
lime and barn-yard manure, makes a
very good manure. IF you still lack
nitrogen, use hotton-seed meal,-ni-
trate of soda is an excellent form Of nj
trogen. The cotton-seed meal will an
swer the purpose if you can use enuf
of it. 1t contains the cheaper form Of
nitrogen and contains as well a small
of potash and phosphates,
while nitrate of soda contains nothing
but nitrogen, and is much more expen-
sive. But with green manures, soft
and barn-yard manure,
and our clay lime. we have cheap
fertilizer for all time.