The aim usually in the use of artificial fertilizers is to so
supplement soil supplies of plant-food as to obtain a profit, and,
as already intimated, the profits for the different crops will be in
proportion to their economical use of the desired constituent. Still,
one should not be deterred from the use of fertilizing materials,
even if the conditions should render the application apparently
wasteful--that is, the farmer should estimate the increase that it is
necessary for him to obtain, in order to be regarded as profitable, and
if only this is obtained, he should not be discouraged. Many persons
seem to have gotten the impression that the use of fertilizers is a
gamble at best, and are not satisfied unless the returns from the
investment in fertilizers are disproportionately large. We very often
hear the statement that by the use of certain fertilizers the crop
is doubled or tripled, as if this were a remarkable occurrence, and
partook of the nature of a mystery. Such results are not mysterious;
they can be readily explained. In an experiment on celery it is shown
that the weight of celery from an application of 400 pounds per acre
of nitrate of soda is two and one-half times greater than on the land
upon which no nitrate was used, and that very great profit followed its
use. This result is not mysterious--the nitrogen applied, if all had
been used by the crop, would have given a still greater increase; it
simply shows that where no extra nitrogen had been applied the plant
was not able to obtain enough to make the crop what the conditions of
the season and soil, in other respects, permitted. These favorable
conditions, however, are not uniform, and variations in return from
definite application must be expected.
It is quite possible to have a return of $50 per acre from the use of
$5 worth of nitrate of soda on crops of high value, as, for example,
early tomatoes, beets, cabbage, etc. This is an extraordinary return
for the money invested and labor involved; still, if the value of the
increased crop from its use was but $10, it should be regarded as a
profitable investment, since no more land is required, and but little
more capital with this return. The waste of nitrogen does not result in
loss.