Atlanta semi-weekly journal. (Atlanta, Ga.) 1898-1920, 1910-08-09
AND MIXING
FERTILIZERS FOR IRISH POTATOES
SOURCES OF NITROGEN.

SOURCES OF NITROGEN.
Where this method Of practice is fol-
lowed liberal applications OF phosphates
and potash should be made. One hun
dred to zoo pounds OF high-grade acid
phosphate should be used. and at least
100. or better. zoe pounds OF high-grade
sulphate OF muTiate Of potash. In the
absence of vegess BILE matter, OF where II
becomes necessary to use heterogeneous
fertilizers for potatoes. nitrate OF soda
which is a quick-acting and readily
available fertilizer can be used prOfita-
bly,. OF course, cotton seed meal. dried
blood, tankage, fish scrap and various
other Amendments may be used Where
any OF the slower acting forms OF or
ganic nitrogen are used. however. the
complete fertilizer should be applied
early in the season. and probably under
the drill row so as TO be within easy
reach OF the roots Of the growing plant
which at best has a short season In
which 20 develop. The advantage OF nj
trate OF soda as a source OF nitrogen lies
In the fact that II can be applied fire.
quently and as a top dressing after
growth has started
SOURCES OF PHOSPHORIC ACID.
Several forms OF phosphates may be
used TO supply phosphorfc acid For
instance, floats or very finely ground
phosphate rock might be mixed with
farrnyard manure at the rate OF loo
pounds per ton as IL is taken from the
stable from day to day. Floats may
also be applied on land that is acid and
very literally supplied with vegetable
matter but il is very doubtful II II Will
be quick enough in its action 10 meet
the needs OF the potato crop. At the pres
emit time il would seem as though high
grade acid phosphate provides available
phosphorus in the cheapest form Basic
Stag and bone meal may both be used
but experiments seem to indicate that
they are too slow acting and expensive
in proportion to acid phosphate TO JUST
~ their extensive use for potatoes
SOURCES OF POTASH.
Potash may be supplied in the form
OF muriate, sulphate or kainit- Muriate
and sulphate contain about the same
amount OF available plant food. and be-
ing the most concentrated are therefore
the most desirable to use II is gen
eraIly believd that muriate interferes
TO some extent with the cooking quality
OF the potato and not as desirable 10
use on that account as the sulphate, but
as shown later on. there does not seem
10 be any substantial reason why muri-
ate should not be used with advantage
In most instances. The question may
he asked as 20 the ACCESSIBILITY of using
wood ashes, but as 10 will be seen In
the next paragraph. this would be
very Questionable and unfortunate prae-
tice.
VALUE OF POTASH FERTILIZERS
ON LAND INFESTED WITH SCAB-
Potatoes are affected by one serious
disease known as scab. Oospores sceoies'
which has caused considerable loss IN
various sections which unfortunately
frN cannot
be gotten rid Of in many years. This
subject has been quite thoroughly in
ve<tigated, and some interesting data
obtained relative to its control At the
Rhode Island station II was found that
the materials which favor the develop
rnent OF scab when applied to the land
are Cd fresh stable manure OF all kinds.
(2l wood ashes, CD air-slaked or caustic
lime 90 carbonate OF soda, (5) potash.
(s) lime and ca magnesia- Those ma
teriais which do not make the scab
worse and which may often and do de-
crease IL are % most forms Of CONNER
ciaI fertilizers. C2) potash salts. except
potassium carbonate. CD land plaster.
az common salt. and go ammonium
suluhate. Nitrate OF soda IL used In
large quantities may favor scab. but
with ordinary amount no serious results
are likely 70 ensue. Where the soil s
badly infested and conditions are ia
vorabIe to the disease. acid phosphate.
ammonium sulphste. kainit, sulpha;s,
and muriate OF potash are materials
which applied as fertilizers tend gradu-
ally TO reduce and alleviate the effect of
the scab.
These very important and striking con-
illusions are worthy Of the most serious
attention BY all potato growers. as they
show most effectively that potash salts
can be applied with safety arh in large
amounts 10 land infected with scab. and
that they tend 20 reduce and dissipate
the Influence Of this most pernicious
potato disease They also show conclu-
efvely that Il would be exceedingly I'M
fortunate to use wood ashes as a source
Of potash and that land intended for
potatoes should be lined These conclu-
sions are based on the fact clearly
demonstrated that potato scab thrives
best in an alkaline soil. or IN the pres
ence OF certain fertilizers and chemical
agents which promote or favor slkalin-
fty Acid soils In the presence of some
OF the chemical salts referred 20. par
tfcularly the potash salts. are unfavor-
able 20 its development These facts also
indicate the very great importance Of
using large amounts OF vegetable matter
supplied through green crops plowed I'M
der on land affected with scab. as the
green crops tend 20 make the soil acid
and keep II so. These results show con-
cIusively. therefore. that potash salts are
the only source OF potash which should
be used on potato land which Is infected
with scab.
WHEN AND HOW TO APPLY FER
TILIZERS
The well-known retentive and absorp-
tive power OF most soils ror potash and
phosphates indicates that these elements
may be added to the soil some time in
advance Of planting. and in this case IL
might be advisable II level culture were
pursued 20 apply the fertilizer broadcast.
Organic forms OF nitrogen. such as would