Evening public ledger. [volume] (Philadelphia [Pa.]) 1914-1942, 1917-10-03
"INEXHAUSTIBLE.
POTASH SUPPLY"
Agriculturists Urged to Expert
ment With Feldspar-Com-
plains of Workhouse

To the EditoH Of the Evening Ledger:
Sir-The alarm caused by the shortage
of potash for agricultural purposes In this
country, due to the cutting off Of the Ger
man supply, and which has been the oc-
casion OF several" letters In the columns of
the EVENING LEDGER discussing the possi-
bllity of increased production would seem
to ignore an inexhaustible supply of potash
which, with some possible and as yet not
well-defined limitations, is obtainable by
virtually every American agriculturist at
reasonable cost.
A large proportion of the rock underlying
the American continent consists Of feldspar.
much of which contains potash in varying
proportions up to 1873 per cent. To extract
this potash commercially has long been an
important problem of the industrial chemist.
thus far unsolved. II has long been known,
however, that potash feldspars 1ecompose
under the action of the elements, llberating
their potash in a soluble form available
for plant food Under ordinary conditions
this decomposition takes place very slowly
and the liberated potash Is available for
only the slowest growing plants, such as
trees. BY greatly increasing the rock sur
faces to be acted upon by the elements.
which can be accomplished by reducing the
rock TO q fine powder, the process may be
greatly accelerated and, theoretically at
least by this means sufficient potash might
be liberated In a single season, from finely
ground potash feldspars, to feed ordinary
crops economically
Occasional experiments had been made
during half century until our Agricultural
Department collected the work of preceding
| investigators and instituted a series OF ex-
periments to try out the theory practically.
In the first place a very interesting prin-
| ciple was discovered: Whereas powdered
| feldspar liberated little potash by the ac-
| ton of water alone when by the growth of
/ hxyO ~ he araf fad
| potash was removed as liberated, nearly all
| the potash was completely liberated in a
| comparatively short time The experiments
/ as whole showed that under the conditions
| OF the tests the potash of finely ground
| feldspar appeared to be virtually as avail
| able for plant food as the ordinary soluble
| salts ordinarily used. The investigator is
4 very cautious in Nhis claims In view of the
fact that the experiments could not be con-
Quoted under all the varying conditions tc
be met with in varying soils climates and
| crops. .5.-.,..
The subject is. however, Of such great
interest TO every American agriculturist who
needs potash in his fertilizer and the pros
| poets Of successful Use seem SO great tha
IL seems incredible that II has not already
been tried by aagriculturists in genera
under every possible condition. At thi,
time Of potash scarcity II is certainly de
| serving of general trial. Probably the onl,
ground feldspar now commercially available
| Is that supplied 10 potteries, and thisrwal
found practicable, although better result
were obtained by finer grinding. The field
| spar used should contain not less than h
10 per cent potash. The experiments aboy
referred 10 are described in Bulletin Nc
| iOl, Bureau OF Plant Industry. M
In view of the fact that In the decomposI
tion Of the feldspar only the action OF waite
was considered, and the well-known fac
that carbon dloxide is an important agen
In the decomposition OF feldspathio rock
; II has occurred to the writer that Il miEh
| be well also 70 observe whether any I'M
provement Is secured by using soils yield
ing carbon dioxide, such as those containin
humus or decaying organic matter. Pos
sibly the feldspar and the organic matte
might mutually hasten the decomposition Q
both. WILLIAM r. JOHNSTON.
shippensburg. Pa, September 2s