Atlanta semi-weekly journal. (Atlanta, Ga.) 1898-1920, 1916-05-30
THE CHEMICAL SIDE OF THE FER-
rIIIZER PROPOSITION

l1l<IAA@iN 4lSAN.
Commercial plant food has only been
used as such for a comparatively short
time. The first intimation of the advis-
ability of such a practice came with the
beginnings of agricultural chemistry.
The men who founded this practice are
now long since dead. Liebig was enc
of the first to undertake the analysis
Of plants and to show the relation
between their composition and the soil,
and to point out the practicability of
increasing the growth of crops on the
soil by supplying certain elements es-
sential to the welfare Of plants in which
it might be deficient This simple sug-
gestion opened up a wonderful field for
research and it was not long before hun
dreds of men were busy in ascertaining
ncw and important facts as regards the
composition of the soil, its primal de-
fects, and the needs of the plants
grown thereon. Before long it was dis
covered that such elements as nitrogen,
oxy gen, hydrogen and carbon are all
obtained from the atmosphere, but that
potassium, phosphorus, calcium, magne-
SUM, iron and sulphur were obtained
solely from the SOIL
With the discovery of these funda-
mental facts began the development Of
what is known as the commercial fer
| tilizer industry which essentially indi-
Gates the proper plant food formula
adapted to meet the needs of our prin-
| cipal crops and the most marked defects
! in our type soils. The application Of
these plant food rations, in other words,
is supposed to bring about an equili-
brium between the soil and the plants
grown thereon, and to thus enable larg-
er and more profitable crops TO he
| grown. OF course, each plant food ele-
ment exerts a given effect through their
action is so interrelated and interde-
4 .JsE ~1naRG
| the function of one ends and that of
another begins. In a general way, how
ever, nitrogen is concerned in the growth
of limb and leaf; phosphorus in the
production of grain and fruit and the
fastening of maturity; and potassium
| in the transference of food from tho
leaves to the body of the plant; and
calcium in the neutralizing of organic
acids
The use of fertilizers seems to be-
come more and more important as agri-
| culture ages in a given community or
country. This is due to the great loss
which our soils suffer by way of ero-
sion, thereby Swimming off the surface
of the ground, as it were, and taking
away the cream of the soil with the
| quickly available plant food which it
contains. Where crops are removed from
the land and sold they carry away a
considerable amount of fertility; so
much so in fact that in some instances
! land which a few years ago produced
40 bushels of wheat per acre will now
not produce more than 10 or IL. The
same is also true of corn and cotton.
! Drainage is also responsible for carry
ing away a considerable amount of plant
| food. When nature had the matter in
charge she kept the earths surface COW
| cred with layer of vegetable mold
and humus, thereby holding good part
| of the water which falls as rain. Now
with clean cultivation and open fields
| in which crops only grow a portion OF
| the year, the loss through drainage is
naturally greatly aggravated. The open
climate in the south makes the loss or
| plant food excessive and the one-cro
system has aggravated the wastage of
our lands. Thus, we seem to have reach
ed a stage in our agriculture when the
use of some form of commercial plant
| food is essential.
The question now arises as to what
should be used and how 1t can be
most cheaply obtained. OF the primary
elements of plant food nitrogen is the
most costly. 1t may be obtained in
commercial form from nitrate of soda,
sulphate of ammonia, calcium 'cyanamid,
cotton seed meal, dried blood, tankage,
fish scrap and animal manures. Large
quantities of nitrate of soda have pre-
viously been obtained from Chilli, but
the supply has been decreased con-
siderably by war conditions and the
excessive demand for nitrates in the
manufacture Of explosives. The supply
of cotton seed meal is probably about
normal, and probably more calcium
g, vanamid is being manufactured in this
country at the present time than ever
before The supply of sulphate of am
'nonia made in the United States Is
normal, but possibly the quantity OBJ
tainable from Europe has been reduced
Il by war conditions. Dried blood, tank
age, fish scrap and animal manures
should all be available.
| Phosphoric acid may be obtained from
acid phosphate made by grinding and
treating floats derived from South
Carolina, Florida and Tennessee rock
with sulphuric acid. This has been
our principal source of phosphoric acid
| in the past and probably is one of the
most. desirable sources as we'll. The
cost of this material, however, has be-
come excessive on account of the tre-
mendous demand for sulphuris acid for
the purpose of manufacturing war ma
terials. OF course. Thomas Stag or basic
Stag, bones and manures all supply
some Of this element and they should
be utilized to the best possible ad-
Vantage.
Potash has been principally obtained
in the past from Germany in the. form
loG sulpkate, muriate and kainit This
source of supply has been cut off and we
must depend on the use of wood ashes
tobacco stems, cotton seed meal, aiunite
the giant kelp of the Pacific coast, and
the small quantities of potash which
may be manufactured in the dessert
regions from feldsparatic rocks.
Lime can of course be secured in the
form of ground rock or caustic lime
Ut is valuable as a corrective of acidity
in soils and can best be used in associa-
tion with legumes. the other elements
needed by plants of which there are
many need not, as a rule, be supplied in
commercial form.
The question of soil fertilization
should, therefore, not be a difficult one.
especially since much of the nitrogen
needed can be supplied by turning under
green, leguminous crops which have the
power of gathering and assimilating nj
trogen from the air. Animal manures
should also be used more extensiv ely
than in the past. Great quantities of
animal manures have been wasted A
little attention to this matter will enable
the farmer to increase the nitrogen sup
ply and lessen the amount Of money
which IL is necessary for him to spend
for commercial fertilizers.
Fertilizers are mixed commercially