FLORIDA STATE HORTICULTURAL SOCIETY. 
121 
SOME PROBLEMS OF FERTILIZING. 
By E. S. Hubbard. 
Mr. President, Ladies and Gentlemen: 
In presenting this individual report as 
a member of the standing committee on 
fertilizers I shall depart from the ques¬ 
tion of fertilizers as mixtures to their ef¬ 
fects in fertilizing. 
The A. B. C. of fertilizers is well un¬ 
derstood by all intelligent horticulturists. 
The nature of the various materials, their 
percentages and the proportions neces¬ 
sary for complete or special fertilizers 
have been fairly well worked out in prac¬ 
tice but our knowledge of the physiolog¬ 
ical effects and defects of their action 
on plant life is in its infancy and I wish 
to suggest a few of the problems that 
have occurred to me on which exact sci¬ 
entific knowledge would be of great value. 
The primary elements of plant growth 
are nitric ancl phosphoric acids. Nitric 
acid to nourish and stimulate the - life 
principle and phosphoric acid to act as 
a clarifying and transferring medium in 
the interconversion of carbon dioxide 
into fluid gums and sugars to the fixed 
forms of starches and dellular tissue. 
These acids, however, are corrosive 
and unstable. They can only be assim¬ 
ilated as acids in a high state of dilution 
in small quantities. They must be neu¬ 
tralized by combination with alkaline 
bases when they are gradually dissolved 
or absorbed by the plant rootlets. 
They are most healthfully assimilated 
as nitrate of potash and phosphate of 
lime. This is the ideal condition of plant 
fertilization. The other salts found in 
plants are either accidental or of small 
tonic value. Unfortunately, however, 
our soil conditions are hardly ever ideal 
and we have to use many commercial 
materials that must undergo chemical 
changes either by bacterial nitrification 
in the case of ammoniacal compounds or 
of decay and disintegration in the case 
of phosphates before they can be most 
healthfully assimilated by • plants and 
there are several commercial chemical 
salts one element of which is unnecessary 
or detrimental. 
In a state of nature the equation of 
plant nutrition is self-regulating. Given 
a soil with sufficient mineral bases, moist¬ 
ure and drainage, all the plant waste and 
decay remains as humus to hold the ni¬ 
trogen and other food elements and the 
soil increases in fertility till limitations 
of room, light and air define the amount 
of vegetation that can flourish. 
In agriculture and horticulture all this 
is changed. Plants chiefly foreign to the 
soil and climate are grown and the mar¬ 
ketable products are removed, thus car¬ 
rying away the stored-up fertility of the 
soil, while the remaining fertility is often 
still further dissipated in the air and 
drainage by improper exposure and cul¬ 
ture. 
Here man, to continue growing crops, 
steps in with artificial fertilizers com¬ 
posed largely of unassimilable, unneces¬ 
sary and even detrimental materials and 
often applies them far in excess of the 
plant’s needs or requirements. 
The commercial results are then meas¬ 
ured by the endurance or tolerance of the 
plants. 
I consider this the great unwritten 
