Atlanta semi-weekly journal. (Atlanta, Ga.) 1898-1920, 1917-05-18
Plant Food Per Acre IN Predominant
Soils of Georgia

In studying soils ntelligently we
must give consideration TO the total
store OF the more important elements of
plant food IL cotnaius. Naturally crops
require a good many elements for their
perfect development. but ordinarily il is
only necessary TO supply three or four.
OF the fifteen predominant soil types
found I'm Georgia. and no doubt IN any
other states as well. IL appears that
the total store Of phosphoric acid varied
from 1.ISS up 10 5.440 pounds in the
drst 81 inches OF soil. the nitrogen from
l.1sa up 10 5.4lS pounds; the potash
from s.155 up to ls4.54o-
To correct acidity in these soils would
require an application OF limestone va
ryinE- i'm amount from 226 up to 1897
pounds. On many Of these lands no
LIME has been used in the past nor
viii il be in the future. yet their acid
condition makes them unfriendly TO
crops and TO the bacteria which asso-
ciate themselves. with the nOdules on
the roots Of leggminous crops and give
them their power OF assimilatiug at
mospheric nitrogen Hence the cor
rection Of soil fertility becomes a de-
termining factor in crop production.
Naturally. all Of the above soils can
not be fortified or handled in the same
manner Il
Congaree loan containing 1870 pounds
OF potash TO a depth OF 81 inches. or
apparently superabundance of this ele-
ment may still respond TO applications
Of commercial potash. because this huge
store Of potash is not available by rea-
son of A failure to handle the land
properly or possibly because of its com
binatiOn with other elements which
makes its transference into a soluble
form so that plants can use II an ex-
ceedingly difficult undertaking.
The figures i'm this table are inter
esting and instructive. however. be-
cause they indicate the total re-
sources OF plant food at the command
OF the farmer and from them he can
make many deductions which Will ena-
bIe ham TO modify his practice advan-
taseously For instance. the cecil clay
loan or red land which is a predominant
ing type in many parts OF Georgia is
seen to contain 2.4OO pounds of nitro
gen Under the most favorable condi-
lions of practice and management not
over per cent of this nitrogen viii be-
come available TO a growing crop in any
one year. In other words. not more than
IS pounds Of this element can be count
ed on for crop production. If ii re-
duires approximately 81 pounds of nitro
gen to make bale Of cotton. including
the plant, il is quite evident, there
fore. that without the addition of
considerable amount Of nitrogen in COM
merciaI form through yard or green
manures or compost that much less than
a bale will be gathered. for II has now
been pretty clearly established that We
cannot count on the plants taking up
probably more than twO-thiTds of the
available plant food normally contained
1rHFE rFa al
form Hence. the soil under the cOndi-
tions indicated would supply only
about s. pounds. leaving the farmer TO
supply at least 40 pounds, or the amount
contained. say in 500 TO 200 pounds Of
cotton seed meal. or goo pounds of sui
phate of ammonia or nearly 500 pounds
Of nitrate Of soda.
In the case OF phosphOric acid. only
I per cent will become available under
the most favorable conditions, and these
do not exist on probably one I'm thou
sand farms; hence. we could only hope
10 secure thirty pounds OF this element
from the soil. II will. however, take