Atlanta semi-weekly journal. (Atlanta, Ga.) 1898-1920, 1916-02-01
A8riicultur!al
0SGduCAtiOn
S AND SUCCESSFUL EARRING
EE:zsz !" ANDREWM OoULE
INFLUENCE OF FERTILIZERS
AND LIME ON COTTON

Fertilizer test plats have now been
maintained in several parts of the state
for the past three years. The object of
the tests conducted on these several soil
areas has been to determine the in
nuence of fertilizers and lime on cot
ton production. The areas of soil on
which the work has been conducted have
been selected with care and the plats
laid off accurately and a careful record
of the work maintained. In order that
the test might be as representative as
possible, the test areas have been dis
tributed as widely over the state as
possible. some twenty-seven of them
now being established. The same
amount and kind OF fertilizer has been
used in all instances and each acre of
land has been divided into ten plats OF
uniform size and character as to soil
drainage and general conditions in so
far as the eye can judge. Careful analy-
ses were made of these soil areas and
the gross amount of plant food they con-
tain determined. Later on other analy-
ses will be made. thereby affording an
opportunity to see whether the store of
plant food in the soil has been decreased
OF Increased lnIOuSH the agency u tie
methods of management followed. The
reader should understand i'm this connec-
tion that these test plats all covered
three acres. and that when one acre is
growing cotton, the next acre is devoted
10 corn, and the third acre to winter
oats followed by cowpeas. In other
words, a systematic three-year rotation
is maintained on these areas with the
idea of building them up through the
us Of fertilizers, lime and green crops.
One rotation period has just been COM
pleted and the results obtained with cot
ton on five areas of land in south Geor-
gia during the years 1912. 1913 and 1914
are presented for the information of the
reader.
The first of the test plats on each
area is used as a check plat. To the
second plat 100 pounds of muriate
of potash was applied; to the third plat.
400 pounds of acid phosphate; to the
fourth plat, lao pounds of dried blood:
10 the fifth plat. 40 pounds of acid phos-
phate and 100 pounds Of muriate of pot
ash; 10 the sixth plate. 14O pounds of
dried blood and 100 pounds of muriate
Of potash; to the seventh plat. 14O
pounds of dried blood, 400 pounds Of
acid phosphate; to the eighth plat, 40
pounds of dried blood, 400 pounds of
acid phosphate and 100 pounds of mu-
riate of potash; to the ninth plat, 5000
pounds of finely ground rock phosphate
and 400 pounds of acid phosphate; to
the ninth plat. 5000 pounds of finely
ground rock phosphate, 40 pounds Of
acid phosphate and 100 pounds of mu-
riate of potash.
The average of three years trials
shows that the check plat produced Gil
pounds of seed cotton. The yield Of
seed cotton was increased by so pounds
where 100 pounds of muriate of potash
were applied. When 400 pounds of acid
phosphate were applied the yield of seed
cotton was increased by 81 pounds
When 40 pounds OF dried blood were
used the yield of seed cotton over the
check plate was raised to 9S pounds. The
use of acid phosphate and potash to-
gether raised the yield over the cheek
plat by 159 pounds. When nitrogen and
phosphoric acid were used together the
yield of seed cotton over the check plat
was raised to 2OS pounds When
complete fertilizer, consisting of the
three elements in the quantities shown
above was applied the yield of seed
cotton over the check plat was raised
to 303 pounds. In the case of rock
phosphate combined with acid phos-
phate. the increase over the check plat
was 95 pounds; and with rock phos-
phate, acid phosphate and potash COM
bined, the increase over the check plat
amounted to 155 pounds.
When lime was added to the soil at
the rate Of 800 pounds of caustic lime
and 5000 pounds of raw ground rock,
the check plat show an increase over
the area where no lime was used Of 80