Atlanta semi-weekly journal. (Atlanta, Ga.) 1898-1920, 1920-02-17
AGRICULTURAL EDUCATION
81 DR.. ANDREW NJ. SOULE

+ from this source would therefore
cost approximately 81 cents. If the
cotton seed meal contains 6.59 per
cent of nitrogen, the cost will be
around Sc cents a pound. 1t is true
that cotton seed meal contains con-
siderable quantities of phosphoric
acid and potash and that these ele-
ments are absent from nitrate of
soda. Giving the largest measure of
consideration possible to the value
of these two elements, it is evident
at once that nitrate of soda will fur
nish available nitl ogen at a much
lower relative cost than cotton seed
meal. Even if the price of nitrate
of soda be raised considerably, it
would still have a large margin of
advantage in the matter of cost per
pound of available plant food.
There is an opinion that nitrate
of soda can not be used in large
quantities in the soil. This is a mis-
take. This element is not as readily
leached from the land as some per
sons imagine. Particularly is this
true if it is buried to a fairly good
depth in the soil as would certainly
follow it's application to cotton or
corn. The fact that it is so quickly
available makes it desirable that the
crops be planted on the land and
developed so they can use it shortly
after it is put in the soil Crops
can, of course, only take nitrogen up
just so fast even under the most ia
Vorable conditions, and hence it will
have to stay in the land quite
while in order for it all to be assimi-
lated On clay lands in particular
there would be comparatively little
loss even though this condition per
tanned. On sandy soils there would
be more danger from teaching, espe-
cilaly in a very wet season, but even
under these conditions [ am still of
the opinion that it could be used
with safety and advantage.
soda Nitrate Valuable
There is also a popular notion that
only a small amount Of nitrate of
soda should be used in a mixed fer
tilizer; in other words, that most of
1t must be reserved and used as
side application. This is a mistake.
There is no. objection in the world
to using 500, coo or 700 pounds of
nitrate of soda, if this becomes ad-
visable, in a fertilizer formula.
Amounts as large as these are used
frequently by truck growers and
others who make exceptionally heavy
applications of commercial plant
food. The same relative results will
be obtained from these heavy appll-
cations on field crops as under truck
crops. There is no objection to mix
ing nitrate of soda with acid phos-
phate or potash; hence one need not
hesitate to utilize nitrate of soda
even to the exclusion of cotton SEED
meal under existing conditions. 1t
can, of course, be combined with
blood or tankage, fish scrap or even
cotton seed meal satisfactorily. 1t
is all a question of price as L see
the situation at the present time.
In regard to carriers Of phospho-
rus. I am still of the opinion that
preference should be given to acid
phosphate. This is the raw ground
rock treated with an equal weight
of sulphuric acid. By this process
at least 10 per cent of the phospho-
ric acid contained is made available.
In all the tests and observations we
have made as yet acid phosphate
seems to have given us the best re-
suits in supplying the necessary
phosphoric acid to our crops and
soils in form which could be most
quickly and advantageously used
Basic Stag is now being highly rec
commended, but We are unable to as
certain that any considerable pro-
portion of the phosphoric acid in
this material will become available
during the first year after it's ap-
plication. The same is true of fine
! ly ground rock phosphate or soft
phosphate rock as the case may be.
Where these materials can be used
on land rich in vegetable matter o"
in association with heavy applica-
lions of yard manure or under con-
ditions where one can wait Ions
lime for results, there is certainly
no objection to their use; but to APP
Hly it for use this year on land de-
voted to cotton where the principa;
thing needed is that of fastening
maturity would not In our judgment
&c good practice, and it is for this
reason that we are disposed to
think that under existing conditions
acid phosphate is the best material
lor the farmer to use under truck
or field crops.
Potash Available.
AS for potash there is some Of
this material available from various
sources. That which comes from
french Alsace Lorraine is of the
same character and type as the Ger
man potash which we obtained in
pre-War times. My understanding
is that the case of this material is
still three times that of the pre-
war prices. Even then on many Of
our soils l am disposed to think
that some potash can be used with
advantage and profit. The question
is from what source should we OBJ
| tain the necessary supplies Ameri-
can potash seems to contain some
2lkali, particularly that known as
black alkali. Apparently, this makes
dts use injurious on fruit trees. es-
D@cially where there is more than
( half per cent of this element pres
eht. To avoid all danger, therefore.
II would seem best that orchardists
use only the imported article On
! ,,,-C