Platb XVI. Fig. 32. Tobacco, Lancaster area,

Pennsylyania ** 888



FEETILIZERS



CHAPTER I

NATURAL FERTILITY OF THE SOIL, AND
SOURCES OF LOSS OF THE ELEMENTS OF
FERTILITY

There is no one question of greater importance to
the farming industry than that of soil fertility. In
order that the industry may be successful, it is not enough
to produce crops; it is necessary that their production
shall result in a genuine profit. That is, it is not enough
to produce crops which bring more than they cost in the
way of labor and manures, without taking into consid-
eration the effect of their growth upon the future pro-
ductive capacity of the soil. The relation of the outgo
and income of the fertility elements is an important
factor in determining profits, and must be considered.
The farmer who secures crops that bring more than they
cost, and who, at the same tune, mamtains or even
increases the productive capacity of his soil, is, other
things being equal, the broadly successful farmer. Many
farmers are able to accomplish this object because of the
knowledge they have acquired through long years of
experience, rather than because they possessed in the
beginning of their work a definite knowledge of the fun-
damental principles involved in crop production, and

B 1



2 ' • ' Ferhlizers

upon the observance of which their success depended.
One of the first needs, therefore, in the use of conunercial
fertilizers is a more or less definite knowledge of what
constitutes fertility, and of the principles which under-
lie crop production.
