The Maryville times. (Maryville, Tenn.) 1884-1944, 1914-10-02
REMEDIES F0R POTASH
SHORTAGE
BY Prof. Il. a. Huston.

Various suggestions have been made
in regard to the steps to be taken by
farmers in reference to the shortage
of Potash in their fertilizers, caused
by. the greatly reduced shipments OF
Potash from Germany since the first
Of August. Most of the Fertilizer Com
panies have endeavored to make the
Potash on hand go as far as possible
by selling for the present brands OF
complete fertilizers containing only 2
or per cent of Potash and withhold
ing from sale brands containing larger
amounts.
The suggestion that some or all Of
the Potash be replaced by phosphoric
acid is absurd, for every schOolboy
knows that one plant food cannot take
the place of another. There are some
indirect fertilizers, such as lime, gyp-
sum and salt that can release limit
ed amount of Potash from some soils
that contain hydrated silicates of Alu-
nina and Potash. But if these soils
have already been treated with lime
or have received repeated dressings
OF the usual forms of fertilizer con
tanning soluble phosphate with its ac-
! companying gypsum, then the Potash
in the hydrated silicates has to large
extent already been replaced and the
use of more lime or gypsum or salt
could not be expected to release much
| additional Potash. Ground limestone
or oyster shells act too slowly to be
used as Potash releasers.
The residue of soda left i'll the soil
by nitrate of soda is more effective in
releasing Potash than is gypsum and
hence goods, in which the nitrogen is
/ largely in the form Of nitrate of soda;
may have a special value in the pres
ent emergency.
1t is often stated that decaying or
ganic matter releases Potash from the
soil, but there seems to be no direct
evidence of this. On the contrary,
DR.. S. Peacock states in the American
Fertilizer of Sept. 5, 1914, Several
thoroughly competent researches have
shown that decaying organic matter
has little effect on converting inert
mineral plant food in the soil into
available form"
In any soil the amount of Potash
capable of being released by these in
direct means is a very small fraction
OF the total Potash in the soil, most
soluble as window glass. There is no
known profitable method for render
ing this inert Potash of the soil avail
able fast enough TO provide for profit
able crops. Whatever temporary ex-
pedients we may employ in the pres
ent emergency, we must keep in mind
that the Potash thus removed from
| the semi-available soil reserves must
later be replaced if we are TO main
| tain the soils productiveness.
There is danger In the statement
! that farmers have been using an ex-
cess OF Potash. Crops use ON the av-
serage about two and one-half times as
much Potash as phosphoric acid, while
/ the average fertilizer sold contains
/ only half as much Potash as phos.
/ pHOktC dClos yet HO Oio CldluIS Iudl
we are using too puch phosphoric
acid. The Potash remaining from pre-
vious fertilization is practically moth
ing except in the limited areas where
a ton or more of fertilizer has been
used per acre on truck crops. Very
rarely is half as much Potash applied
to the wheat, oats, corn or cotton crop
as the crop removes. y
The Potash mines are so numerous
and the stocks on hand so large that
supplies can be promptly sent for.
ward, as soon as European conditions
permit freight shipments to be re-
! sumed.