Montgomery County sentinel. [volume] (Rockville, Md.) 1855-1974, 1916-04-14
Potatoes without Potash.
some EXPERIMENTS In New JERSEY THAT
INDICATE A BENEFIT FROM THE
WAR SHORTAGE.

of corrosive sublimate in thirty gallons of
water for an hour and half before cutting
is very effective in reducing loss from scab
and blackleg. This solution is virulent
poison and should be handled with care.
New Jersey potato growers believe in
cutting the seed in generous-sized pieces
giving more consideration to the size of
the pieces than to the number of eyes each
piece contains. Fourteen to fifteen bushels
OF potatoes are required to plant an acre
in most sections of the State. and growers
have come to believe it false economy to
reduce the amount of seed by skimping
the size of the pieces. Experiments car
ried out in Monmouth county last season
went to prove that a large, chunky seed
piece had profound effect upon yield.
Experienced growers believe that one of
the essentials to the production of pro-
fitable crop of potatoes is deep blowing.
and great many Of the best potato fields
are plowed to depth of ten or eleven
inches. OF course this depth cannot be
attained in one year without adversely
affecting the crop-producine power Of the
soil. But by blowing little deeper each
time potatoes come in rotation and turning
under humus at every opportunity the sur
face foot of soil is gradually thoroughly
lOosened and impregnated with decayine
organic matter. Thorough and deep work
ing Of the plowed soil by the use of the
cutaway and other harrows is necessary
Thorough preparation makes weed destruc-
ton much easier and liehtens the labor
for the whole season.
Because the potato is voracious feeder
and because the plants make most of their
growth in cool weather. before soil bacteria
can make slowly available food soluable,
potato growers have come to depend more
and more upon chemical fertilizers. In
the past the favorite fertilizer in New Jer-
sey was mixture Analysing four per cent
ammonia, eight per cent phosphoric acid
and ten per cent potash. This was applied
at the rate of 1000 to 1000 pounds to the
acre. heavier soils seeming to stand heavier
fertilization than lighter soils.
The upheaval in the fertilizer trade this
season. because of the shortage Of potash
and the high prices of other ingredients,
has caused the potato growers great con-
Germ. An interesting series of experiments
in Monmouth county throws some light
upon the problem.
Anticipating the exhaustion of potash
supplies in this country. the Office Of Farm
Demonstration in Monmouth county de-
cided last season to make series of ex-
periments on different soil types to deter
mine, first. whether a profitable crop of
potatoes could be grown without potash !;
second. whether ten per cent Of potash in
fertilizer was profitable, or if the use of
such large amount was useless and
wasteful. Three lots of fertilizers were
used. analyzing ten per cent. five per cent
and no potash, respectively. the percentage
of ammonia and phosphoric acid being
respectively four per cent and nine per
cent in each case. The potash was derived
from muriate Of potash.
Thirty tests were carried out on all types
of soil. and twenty-five were accurately
reported. Fields that had not been in
potatoes for many years. and hence had
no excess of potash, gave practically the
same results as those that had been in
potatoes for a number OF years in success
sion. In all cases the potatoes without
potash came up better and grew faster
than where ten per cent of potash was
applied. In fact, the bright luxuriant green
OF the plots without potash was noticeable
at some distance until late in the season,
showing that potash salts in large quanti-
ties have deleterious effect upon vegeta-
ton.
In eight cases the five per cent mixture
gave better results than the mixture con-
tanning no potash, giving an average in
crease in yields of marketable potatoes of
eleven per cent. In seven cases the five
per cent mixture gave better results than
the ten per cent mixture. This gives the five
per cent mixture the advantage in fifteen
out Of the twenty-five cases reported. In
four instances no potash averaged eight
per cent better than the five per cent pot
ash mixture. and in one instance fertilizer
without potash gave sixteen per cent better
results than the ten per cent potash mix
ture, showing that the soil was either fully
supplied with potash or that too much salt
injured the stand. In only one case did
ten per cent potash prove superior to five
per cent. In several instances the results
obtained with the various mixtures were
practically identical.
Briefly, these results show: First, that
it is possible to get profitable production
of potatoes without potash Second. tn at
the yield is profitably increased by the
addition Of five per cent potash. Third.
that the addition Of as much as ten per
cent potash is unnecessary and may actu-
ally be injurious by reducing the stand.
Results obtained with a two per cent
ammonia fertilizer. compared with the
usual four per cent mixture, show that
the two per cent mixture fully equaled the
four per cent mixture when alfalfa sod was
plowed under; but in the cases where
crimson clover Or vetch was plowed I'M
der. the yield with 2-9-5 fell about six
per cent below that obtained with 49,.
The increase with 49,. 1t should be
remembered. was obtained at an increased
cost Of twenty per cent over the 2-9-5.
1t is not expected that these results,
showing the effect Of varying amounts Of
potash and ammonia on the yields of po-
tatoes. will be taken as conclusive. as only
one seasons work is represented.
Generally seed and fertilizer are applied
at the same time with mechanical planter
A practice which is gaining ground. and
which would seem logical in theory at least,