Atlanta semi-weekly journal. (Atlanta, Ga.) 1898-1920, 1918-07-09

ment. and. il used in certain forms can
he depended upon To help the crop even
when applied relatively late. Ohserva-
tion and experience. however. do not
Indicate this TO he true Of the other ele-
meuts.
Certain studies made relative to the
assimilation Of nitrogen. phosphoric acid
and potash ny corn and cotton may help
70 throw some light on this veNed ques-
tion Just at This slime. II was found
i'm these Investigations that cotton re-
quirei approximately 2l2 days TO ma
ture. and corn ia days. With cotton
the first form appeared at the end OF
So DAYS. the first bloom At the end of
s. days. the first open boil at the end
Of IFS days. while maturity occurred
at the end of 30 days. With corn the
fourteenth blade had formed At the end
or b days. the tassels appeared at the
end Of 81 days: the pollen was shed at
the end of 3 days; the glazing stage
developed at the end of 100 days. while
the corn was ready for the shock at
the end of ia days.
In the case of cotton il appears that
30 pounds of nitrogen had been as
simulated in 81 days: AIS pounds in 50
days; 81 pounds in l23 days and Coz
pounds in 2I2 days In other words, by
ton had taken up all but 10 pounds of
the total nitrogen assimilatel through
out the growing season. This would
iriicate that side applications of nitro
gen for this crop should be put on
relatively early. There is much cot
ton i'm a stage Of development at this
time that would no doubt be benefit
ted by such applications which should.
however. be made promptly.
= = Of raa# grn-
cen had been assimilated in IS days;
rs pounds in 81 days; ass pounds in
3 DAYS, and 1871 pounds in ia days.
Here again the corn had taken up by
Gar the greater part Of the nitrogen it
used in a little over so days after the
crop had been planted. These figures
represent the amounts of nitrogen as
simulated by a crop of cotton producing
bale of lint per acre and a crop of
ror-ts making a yield of so bushels per
acre.
In the assimilation of phosphOric acid
cotton exhibits much the same charac-
teristics as it did in the case of nitro
gen. In other words, over three-fourths
of the phosphOric acid was taken up IS
DAYS after planting or when the first
bloom appeared. and practically all of
il in 1913 days or when the first boil app
been taken up at the end of Sc days. or
by far the greater part of the amount
of this element assimilated throughout
the entire growing period. While this
element is taken up rather rapidly, it
is not taken up quite so quickly as nj
trogen and is taken up somewhat more
uniformly throughout the growing sea-
son. This is an added reason from our
roint of view why this element should.
aS a rule. be incorporated with the soil
at or befOer the time the crop is plant
ed and thus given the longest period of
time in which to render its maximum
service TO the growing crop.
The assimilation of potash occurred
largely in the early part of the growing
season. For instance, the cotton crop
took up 80 pounds in the course of 2l2
days. hut 255 pounds of this amount
had been taken up at the end of 65
days With corn the total amount as
simulated was 70.1 pounds, of which
G14 pounds had been taken up at the
end Of sc days. The conclusions reach
ed. therefore. relative to the application
Of phosphoric acid held good in the
case of potash as we'll. and do not lead
us to advise the use of either of these
elements as side applications late in the
season. If they are to be used they
should be put on soon after the crop Is
out of the ground. but even then they
are not likely to have an opportunity to
exert their maximum benefit, as all in
yrS;iCations show the hest returns are
obtained from phosphoric acid and pot
aeh when well mixed with the soil. and
this is never accomplished so satisfac-
toriIy after the crop is planted as be-
fore or at the time of seeding. The
chief advantage Of phoSphoric acid in
crop economy is the stimulation of the
development NJ grain and seed and the
--rstening of maturity. These things be-
ing true IL should therefore he given
$50 hest opportunity to perform its MAN
-Inctiou and purpose satisfactorily.
At this season of the year and under
average conditions. therefore. il would
appear hest to confine side applications
chiefly to nitrogen carriers, unless the
~-on still has a growing period of at
least ninety days ahead of lit. What
materials can be used and how should
they he applied? Sulphate of ammo
MIA Is no longer available. all of il hav-
ing been requisitioned for war pur-
poses. Blood and tankage supplies are
m doubt largely exhausted. There is
probably some cotton seed meal stiu
IVA liable. and part of the nitrate of
coda ordered for use as top dressings
on cereal crops. hut which arrived too