n order, and endeavor
to show in a simple manner the best means of managing them in practical
farming.

ALKALIES.

POTASH.

[Do all soils contain a sufficient amount of potash?

How may its deficiency have been caused?

How may its absence be detected?

Does barn-yard manure contain sufficient potash to supply its deficiency
in worn-out soils?]

_Potash_ is often deficient in the soil. Its deficiency may have been
caused in two ways. Either it may not have existed largely in the rock
from which the soil was formed, and consequently is equally absent from
the soil itself, or it may have once been present in sufficient
quantities, and been carried away in crops, without being returned to
the soil in the form of manure until too little remains for the
requirements of fertility.

In either case, its absence may be accurately detected by a skilful
chemist, and it may be supplied by the farmer in various ways. Potash,
as well as all of the other mineral manures, is contained in the
excrements of animals, but not (as is also the case with the others) in
sufficient quantities to restore the proper balance to soils where it is
largely deficient, nor even to make up for what is yearly removed with
each crop, except that crop (or its equivalent) has been fed to such
animals as return _all_ of the fertilizing constituents of their food in
the form of manure, and this be all carefully preserved and applied to
the soil. In all other cases, it is necessary to apply more potash than
is contained in the excrements of animals.

[What is generally the most available source from which to
obtain this alkali?

Will leached ashes answer the same purpose?

How may ashes be used?]

_Unleached wood ashes_ is generally the most available source from which
to obtain this alkali. The ashes of all kinds of wood contain potash
(more or less according to the kind--see analysis section V.) If the
ashes are _leached_, the potash is removed; and, hence for the purpose
of supplying it, they are worthless; but _unleached_ ashes are an
excellent source from which to obtain it. They may be made into compost
with muck, as directed in a previous chapter, or applied directly to the
soil. In either case the potash is available directly to the plant, or
is capable of uniting with the silica in the soil to form silicate of
potash. Neither potash nor any other alkali should ever be applied to
animal manures unless in compost with an absorbent, as