The Democratic banner. (Mt. Vernon, Ohio) 1898-192?, 1916-03-14
GROUND
FGIdSpaF Not Recommended
As A Fertilizer

Washington, d. c., March 1O-Wide
publicity has recently been given to a
statement advocating the use of
ground feldspar as substitute for
potash salts and referring to U. s.
department of agriculture bulletin
No. 104 as authority for the proposed
practice.
Bulletin No. 104, entitled THE Use
of Feldspathic Rocks as Fertilizer"
was published in 1907. This bulletin
discussed the use Of finely ground
feldspar as a possible substitute for
potash for fertilizer purposes, and
was based upon series of expert.
ments conducted by the department.
The results reached were inconclus.
i've, as the following quotation from
the bulletin itsef will show
"a careful reading of the foregoing
pages will show that no claim has
been made that ground feldspar is an
efficient substitute under all circum.
stances for potash salts .... The
question is still open, and systematic
and long continued experimentation
is the only possible method of OBJ
tanning conclusive information on the
subject. go. At the present stage
of the investigation it would be ex.
tremely unwise for anyone to attempt
to use ground rock except on an ex-
perimental scale that would not en-.
tail great financial loss. $50. II is
extremely unlikely that ground rock
will ever entirely displace the use Of
potash salts, for its availability must
inevitably depend upon many modify.
ing conditions, such as the nature OF
the soil, the amount of moisture
present, the character of the other
fertilizers used, and the varying root
action of different crops"
Investigations made since the pub
lication of this bulletin have failed to
show that ground feldspar is of any
general value for fertilizer purposes
The potash content in feldspathlt
rocks is in highly insoluble form
and to be made available for fertilizer
purposes, must undergo chemical
treatment at high temperatures. In
general, it may be said that most
soils contain considerable amount
of potash in this insoluble form de
rived from the disintegration of sill
cate rocks, of which feldspar is one
The application of ground feldspar
therefore, in most instances means
merely the addition of an ingredient
already present in the soil in con.
siderable quantity. Many processes
for rendering the potash in feldspal
available have been proposed, but tc
be commercially successful under
normal conditions a market must be
found for the by-product, and up tc
the present time no satisfactory solu
ton of this problem has been reach
ed.
There are numerous substances the
application of which to soils will, un
der certain circumstances and with
particular soils, bring about increased
crop yields. Ground feldspar may be
included in this class, However, the
cases where increased yields result
from the application of these substan
ces are so rare and the conditions un
der which increased yields may be
expected are so little understood that
their use as fertilizer materials in
general cannot be recommended.
The department has recently re
ceived many requests for copies OF
bulletin No. 104 and many inquiries
with reference TO the use of feldspar
as a fertilizer. The farmers of the
country should be warned that the
department does not recommend such
a practice and that the expenditure
of money for ground feldspar as sub
stitute for potash for fertilizer pur-
poses will probably not result in any
commensurate increase in crop
yields.