Free trader-journal. (Ottawa, Ill.) 1916-1920, 1918-09-11
FElDSPkR NOT ADVOCATED
Ground Feldspathe Rock Not Sub
stitute for Potash Salts.

Wide publicity has recently beer
given to statement advocating the
use OF ground teldspar as \ substitute
for potash salts and referring TO de-
partment Bulletin No. l0i Ms author
ity for the proposed practice.
Bulletin No. l04, epttled The Use
Of Feldspathic Rocks as Fertilizer
was published in 1907. This bulletin
discussed the use OF finely ground
feldspar as possible substitute fot
potash FOR fertilizer Purposes, and was
based upon a series OF experiments
conducted by the department. The re
suits reached were inconclusire, az
the following quotation from the bull
letin itself will show:
"a careful reading OF the foregoing
RACES Will show that no claim has
been made that ground teldspar is an
efficient substitute under all clrcun!-
stances for potash salts, The Ques.
ton is still open, and systematic ana
long continued experimentation is the
only possible method OF obtaining con
elusive information on the subject
At the present stage OF the inresti-
CATION it would b. extremely unwiSe
for anyone to attempt 10 use ground
.oCk except on an experimental scale
that would not entail great financial
los. ..l II il extremely unlikely that
ground rock will ever entirely dis
place the use Of potash salts. for il"
availability must inevitably depend
upon many modifying conditions, such
as the nature OF the soil, the amouif
4 moisture present, tho character OF
the other fertilizers used. and the
varying root action OF different crops
Investigations made since the putt
l!cation Of this bulletin have failed to
chow that ground feldSpar vs. OF any
general value for fertilizer purposes.
The potash content In feldspathic
rocks is in highly insoluble form, and
to be made available for fer'i par
poses must undergo chemical treat
ment at high temperatures. In genera,
I NAV be said that most soils contain
a considerable amount OF potash IN
this insoluble form derived from the
eisinteeration Of silicate rocks, OF
which feldspar is one The applica-
ton OF ground tcldspar, therefore, in
most instances mean. merely the cd
dition OF an ingredient already pres
ent in the soil in considerable guam
tity. Many processes for rendering
.he potash in feldspar available have
been proposed, but to be commercial
" successful under normal conditions
= market must ne found for the by pro-
tuct. and up to the present time no
satisfactory solution Of this problem
has been reached
There are numerous substances the
application Of which to soils will, IN
der certain circumstances and with
particular soils, bring about increased
crop yields Ground feldspar may b"
included in this class However, the
cases where increased YIELDS result
from the application Of these sub
stances are 80 rare and the conditions
under which increased yields may Do
expected are so little understood that
heir use as fertilizer materials in gen
eral cannot be recommended
The department has recently recely-
cd many requests for copies Of Bulle-
tin 104 and many inquiries with refer
cnce TO the use of feldspar as a fer
tilizer The farmers Of the country
should be warned that the department
does not recommend such practice
snd that the expenditure OF money for
ground feld6par as substitute for
potash for fertilizer purposes will
! probably not result in any commen'
/ suratc increase in crop yields.