112 
FLORIDA STATE HORTICULTURAL SOCIETY. 
drawback to their use for a full supply 
of nitrogen is the waste that is bound to 
occur when rains come before the plant 
has used it all. Nitrate of soda and ni¬ 
trate of potash are our general sources of 
this form of plant food at the present 
time, though calcium nitrate is knocking 
at the door of the fertilizer market. The 
nitrate in each of these materials is in 
exactly the same form. The soda in one 
and the lime in another tending to sweet¬ 
en the soil, while the pdtash in the nitrate 
of potash is the straight K2O plant food. 
Another chemical used is sulphate of 
ammonia which in its action is slower 
than the nitrates but quicker than organic 
matter, even when favorable conditions 
surround 'the latter. It also is surer in 
its action and free from the disagreeable 
features attending the change of organic 
nitrogen to ammonia. The continued use 
of this chemical will call for an applica¬ 
tion of lime, as its chemical reactions in 
the soil cause loss of lime; but this is a 
small drawback in comparison with its 
incalculable value, especially to the citrus 
grower. 
Much attention has been given to the 
effects these varying sources have upon 
plant life. Generally speaking, the citrus 
tree demands chemical sources, the pine¬ 
apple, organic sources, while the garden 
products need the different sources in 
well-balanced proportions. These sources 
are all classed as “ammoniates.” 
Now we come to the essential termed 
“phosphoric acid”—another misnomer— 
for there is no real acid in any properly 
prepared fertilizer. All chemical fertil¬ 
izers are in the form of salts. A salt, as 
explained in last year’s paper, is the re¬ 
sult of an acid being destroyed by a base 
displacing the hydrogen. In nitrate of 
soda, sodium has driven out the hydro¬ 
gen, while in nitrate of potash, hydrogen 
has been exchanged for potash. In the 
first, the plant extracts the nitrogen from 
the radical of the acid, while in the last it 
takes food from both radical and base. In 
sulphate of ammonia, it is the base we 
think about as furnishing plant food after 
the necessary nitrifying process, though 
both sulphur and oxygen are essential to 
the plant’s development. In the sulphates 
of potash it is also the base that is bought 
for food. The ammonia in sulphate of 
ammonia and the potash in the sulphate 
of potash are combined with the radical 
of sulphuric acid—exactly the same part 
of sulphuric acid that exists in sulphate 
of lime and every other sulphate—just 
the sulphur and oxygen. These elements 
are absolutely harmless unless combined 
with hydrogen in certain proportions to 
form an acid. There is no possibility of 
reaction taking place for the hydrogen 
has been defeated in a fair fight. The 
base has stronger attractions or it could 
not have displaced it. It is on this prin¬ 
ciple of “a fair fight and no favor” that 
our phosphoric acid is made available for 
use. The radical of phosphoric acid is the 
form from which the plant gets its phos¬ 
phorus, but in the natural state this rad¬ 
ical is in such close combination with lime 
that neither water nor the exudations 
from the plant roots can do much in the 
way of breaking the chemical forces; but, 
fortunately for the grower, the chemist’s 
skill can overcome this difficulty and we 
have either dissolved bone or acid phos¬ 
phate to apply to our fields, knowing that 
