Oxford Democrat. [volume] (Paris, Me.) 1833-1933, 1915-11-30
Needed Potash for Potatoes.

Needed Potash for Potatoes.
In the past, potash has been relatively
plentiful and relatively cheap. For
these reasons few experiments have
been carried out to indicate the amount
of potash necessary to grow q potato
crop. There was great shortage for
the present year and with the continue
tion of the war 1t appears as though fer
tilizers in 1915 would contain only l or 2
percent potash.
Foreseeing this possibility the Maine
Station began this year, on Aroostook
farm, a series of experiments to deter
mine the effect of different amounts Of
potash. Four different mixtures were
used. In each case the fertilizer con.
tanned percent nitrogen (one.third In
the form of nitrate of soda) and 8 per.
cent phosphoric acid. The potash varied
as follows: None, 2 percent, percent
and 7 percent. Duplicate plots were
planted with each mixture. In each
case the fertilizer was applied at tue
time of planting and at the rate of 1900
pounds per acre. Other than the amount
of potash used all the plots were treated
exactly alike.
Throughout the growing season the
vines on both of the no potash plots
we're distinctly brighter green and had
q thriftier look than those on adjoining
plots. The difference was so marked
that it attracted much attention from
visitors at the farm.
While there are slight irregularities
in the yields from the different
plots, the average figures show fairly
consistent increase with the increase
In potash. The plots without potash
yielded 302 bushels OF merchantable
potatoes. The plots with 2 and a per
cent gave practically the same yields OF
32O bushels per acre. The percent
potash plots averaged to yield 33l BUSH
els. This is an increase of 9 percent
over the no potash. This amount is un,
doubtedly large enough to be significant
and indicates that the potash increases
the yield Of potatoes In Aroostook coun'
On the other hand 3O2 bushels per
acre is a good yield, considerably above
the average In the county in 1915. So
far as the results of this one year are
concerned, they indicate that profit
able yield of potatoes can be obtained on
Aroostook soils without the use OF pot
ash for at least one year.
The plots with none or only percent
potash show small fraction more culls
than the other two. However, the diff
ference is not great enough to be OF sig.
nifcance. 1t is clear that the lack of
potash has not resulted in any material
increase In the number of Gull potatoes.
The Massachusetts station has recent
ly published q summary of some results
with potash on potatoes. In their ex-
periments the addition Of potash in
creased the yield of potatoes from 30 to
I2O percent over those plots containing
no potash. Our results for a single year
would indicate that the addition of pot
ash is not 80 important for Aroostook
soils as for those 10 Massachusetts,.
1t should be clearly understood that
the results of a single years experiments
are not to be regarded as final. With
field trials of this sort it Is only after
the results of several years are compared
that final recommendations can be made.
1t is expected that this experiment Will
be repeated next year.
On the results of this one years ex-
periments 1t seems probable that even II
commercial fertilizers should contain no
potash next year slightly reduced but
still profitable yield Of potatoes may be
expected. The station recommends that
growers in Aroostook do not reduce
their acreage next year on account OF
the potash shortage.-Dr. G. D. Woods.