Is not barrenness of the soil responsible for disease in potatoes, for
San Jose scale, Phylloxera, and other similar phenomena. The fields are
manured profusely, it is true, but the very chemical elements which are
not only essential to the development of wholesome plant tissue but
which would also enable the plant to protect itself against parasites,
are not used. Every farmer has observed, for instance, that grass grown
upon cow dung in pastures is not eaten by cows, oxen or sheep. The
instinct of the animals is correct.

In using the term incomplete fertilization, I mean supplying only
potash, phosphoric acid and nitrogen, and possibly lime and sulphur,
when the soil is denuded of several other elements. No matter how rich a
field may be made in these things if it lacks other elements healthy
vegetation cannot be grown in it.

Improper fertilization is another matter. It may consist in dressing a
field with nothing but stable manure, or of applying crude sulphur or
brimestone instead of using calcium sulphate--plus the other lacking
elements. The advocate of crude sulphur certainly does not know how
truly criminal his advice is. It is not to be denied that at the outset
sulphur will increase the crop yield. But in the end--what? The sulphur
will dissolve all of the essential minerals in the soil, and in the
course of four or five years they will all be leached out and it will be
so barren that not even wild grass can be grown upon it. Improper
fertilization may also consist of a dressing of carbonate of lime
applied at the wrong time or in excessive quantity. The effect of this
course will be equally as harmful, namely, the transformation of the
nitrogenous material into free nitrogen which will ascend to heaven.
Without nitrogen albumen cannot be formed, and without albumen the