Evening star. [volume] (Washington, D.C.) 1854-1972, 1906-05-01
A CHEAP FERTILIZER
Experiments Made by the Agri-
cultural Department.
POTASH IN GROUND ROCK
Farmers Are Now Independent of
Germany.
SEVERAL MILLS BEING BUILT
For Grinding Rock for This Purpose,
and the Scheme Looks Like an
Important Development.
MILLS BEING BUILT

One series of experiments have just been
concluded by the Department of Agricul-
ture that promise to be of immense value
to the farmers of the country in furnish
ing them with supply of fertilizer at
very much cheaper rates than has ever
been possible before. and at the same time
emancipating this country from Germany.
which. has heretofore furnished our whole
supply of carbonate OF potash fertilizer 1t
is long and quite an interesting story, and
probably will mean a great deal to agricul-
ture in this country. The most remark
able part of it is. too, that the idea orig
mated in the bureau of roads, which nom
inally has nothing to do with fertilizers.
Last summer when DR.. Cushman of the
roads office was working on some granite
road material he was working In the lab
oratory with very finely powdered rock, and
the idea struck him. as It has struck a good
many other chemists, that 1t was natural
born shame that this country, with an
unlimited supply of rock high in It's per-
centage of potash should have to depend
on other countries for its potash salts for
there has never been any commercial de-
posts of the salts found in this country
as it is in Germany. He extracted
some OF the potash by electricity, though it
Is by no means certain yet that this can
be done on paying commercial basis. But
then he decided that as ground rock was
very cheap 1t might be worth while to try
the experiment of letting the plants do
their own extracting. He tried the ex-
pertinent on his own place up the country
and found that the powdered rock did
actually act as a fertilizer, though the
potash 1t carried was so tied up that it
took the chemistry of nature to extract
1t and feed 1t into the plant. But the first
trial promised well
Bureau of Plant Industry.
The work was then turned over to the bu-
reau of plant industry, and three plots of
tobacco were planted in the greenhouse.
One of these was treated with the imported
German fertilizer, another was left with
out any fertilizer at al and the third was
fertilized with finely ground granite The
granite was high in potash, but it had not
been treated in any way, and If the ex-
pertinent succeeded it simply meant that
there was big new field of home-grow
fertilizer open to the farmer.
Recently the crops of tobacco were cut.
The imported fertilizer had produced a crop
green that weighed 155 pounds. The pow
dered rock produced a crop of 154 pounds
and the unfertiliZed crop was spotted and
ran about 12O pounds or little under.
This crop eXa mined by the experts,
and, so far as could be told, the leaf was
not only just as heavy, but of just as
good texture In the rock fortified patch as
in the patch on which the imported fer
dried now. and it will take a long time be-
fore it is all fermented and properly cured
so that 1t can be made up for smoking and
tested III that way.
But that was a greenhouse experiment,
and greenhouse work to field work is about
like laboratory experiments to commercial
work What succeeds under glass may or
may not go out Of doors. But the depart
ment was well pleased with the results
that it has tried the new fertilizer on crops
Of tobacco up in Connecticut, in Virginia,
Kentucky and Florida. These crops are
now just getting under way. and there is
a great deal Of interest felt in the success
Of the work out of doors. The principal
question seems to be whether there will be
enough water in the natural rainfall to
make the potash In the ground rock avail
able for the plants. During anything like
a decently wet season there is little ques-
ton that there would be water IA plenty.
But 1t is possible that for a very dry crop
there will have to be as much as tenth
of imported fertilizer added to the native
rock
Now the commercial value of the work is
in the fact that the imported fertilizer
costs in this country about Sl0O ton II
Is absolutely necessary fertilizer in the
tobacco field, and there are a number OF
other crops on which 1t is used.
Cost of the Rock
The ground rock, on the other hand can
be produced for about s. a ton, and there
high in potash and is available for use that
the supply could never be cOrnered 1t Is
true that the native fertilizer takes about
two tons to the acre to give the same re-
suits as one ton of the soluble imported
salts. But 1t amounts to So acre for
fertilizer against 800. So the result is not
bad
Several mills are already being erected
one In Maryland and one in New England
for grinding rock for just this purpose, and
there are number OF other concerns that
have talked OF going into the business be-
fore even the field experiments of the de-
partment are finished.
The outlook Is for a very important
change in the fertilizing business in this
country Just where the credit for the
work ultimately will land Is question. 1t
probably will not DC with DR.. Cushman or
the road office. as II is not In their line
of work And the department will get moth
ing out OF ii from the farmers but thanks,
for that Is what the department is there
for. 1t Is not likely. either. that the
smokers of the country will be able TO get
their tobacco any cheaper. but It may leave
q little wider margin OF profit for the
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