Oxford Democrat., 1904-02-02
A Potato Fertilizer.

The station has received numerous
inquiries recently asking for formula
for a home mixed fertilizer for potatoes.
The following is the substance of replies
that have been sent:
A crop of 300 bushels of potatoes re-
moves from the soil about So pounds
nitrogen, - pounds phosphoric acid and
81 pounds potash. A formula on this
basis would carry 5 parts nitrogen, 2
parts phosphoric acid and parts potash.
In preparing field for crop the needs
of the soil to render it fertile are how
ever of grester moment than the special
needs of a particular crop. The results
of numerous field experiments indicate
that the potato does best in soil abun-
dainty supplied with all fertilizing ele-
ments. In the early stages of growth
nitrogen is particularly demanded and
hence considerable part of the nitrogen
should be water soluble. Later when
the tubers are being formed the especial
demand comes for phosphoric acid and
potash
If a farmer has not experimental with
his soil so as TO know to what fertilizing
elements it most readily and protitably
carrying about 3 to 81 per cent. nitrogen,
to per cent available phosphoric acid
and to per cent potash will usually
be found as profitable as any. Bearing
in mind that there is no such thing as
best fertilizer and that different con-
ditions make different demands, some
such formula as the following can be
satisfactorily used per acre until by ex-
detrimental knowledge of his own soil
requirements the individual farmer has
learned better one.
One hundred pounds nitrate of soda
200 pounds cotton seed meal, 500 pounds
tine bone tankage, 400 pounds acid phos-
phate, and 200 pounds muriate, or per-
haps better sulphate, of potash. These
goods are very concentrated and would
probably be more evenly applied if mix
ed with 500 lbs. dry loan, muck, or some
similar fine material. This weight OF
materials would carry 62 pounds nitro
gen, of which about two fifths is water
soluble, 1S5 pounds phosphoric acid, of
which two thirds is available, and lO2
pounds potash.
While the 100 ponnds of available
phosphoric acid in this formula IS about
four times the amount removed by the
crop, the best experimental evidence in
dicates that a liberal application of
available prosphoric acid is profitable
for potatoes. Since phosphoric acid
does not leach from the soil the excess
will be available for the following grain
aud grass crops. Following a crop of
potatoes manured as above usually a
good crop of clover could be grown by
the use of 200 pounds per acre of com
plete fertilizer for starter" and 200
pounds of muriate of potash. This last
with the phosphoric acid left in the soil
would furnish the needed minerals, and
the clover would obtain its needed nitro
gen from the air.
Nitrate OF soda carries about 10 per
cent nitrogen, all of which is water solu-
BILE, High grade cotton seed meal,
carrying 43 per cent of protein, has
about per cent nitrogen, per cent
phosphoric acid and one per cent potash.
High grade finely ground bone tankage
carries ) to per cent nitrogen, about
one-third of which is water soluble, and
about Is per cent phosphoric acid, one
half of which is available. Muriate or
sulphate of potash each carry about 5O
per cent potash. The tankage can be
obtained of the Portland Rendering
Company, Portland, the cotton seed meal
at any feed store, and the chemicals OF
any fertilizer manufacturer. The Saga.
dahoc Fertilizer Company, Bowdoin-
ham, and the Parmenter 4 Paisley
Fertilizer Company, Peabody, Mass,
have taken licences to sell unmixed
chemicals in Maine in 1904.
CHAs. d. WOODS, Director.