Vermont watchman and State journal. [volume] (Montpelier, Vt.) 1836-1883, 1877-05-09
Essential Fertilizers---POtash

As potash is abundant in the ashes of all
cultivated plants, so its presence in the soil
is essential to their growth. 1t must not
only be present there, but it must be there
in state to be easily dissolved in the water
of the soil which the roots absorb.
Potash constitutes portion of many rocks,
especially slate, granite and limestone. The
decay of such rocks furnishes potash to the
soil, and the growth and decay of successive
generations of plants causes it to accumu-
late in soluble condition. The roots of
many plants are able to extract or dissolve
out, a small portion of potash from the hard
rock, gravel or sand, but not enough, usu-
ally, for their thrifty growth. After plant
has thus rendered some potash soluble by its
root action, and then dies, great part of
the potash it has gained remains soluble in
the soil after the decay of the plant. So
each successive generation of plants which
died and decayed where they grew adds to
the quantity of soluble or available potash,
making the land continually more fertile.
Then, when man comes and clears off the
native growth and plants his crops he find,
an ample supply of this, as well as other
kinds of plant food ready for him, and for
time his crops grow and yield well, with
out the necessity of applying any sort OF
manure or fertilizer
But year after year he removes the cror,
and with it the potash it contains, until at
last there is not enough remaining in an
available or soluble state for the needs of
the crop. The land is "run out" as we say,
and must be MANFRED. That is, the plants
have taken up nearly all the plant food they
can find, and succeeding paintings suffer
from famine.
Usuallyitis not the potash, but phosphoric
acid, that is found irst to fail, in our ordi
nary New England soil. Many of our heavy
soils have still plenty of soluble potash in
them, and when supplied with phosphoric
acid and some form of heterogeneous manure,
they will give good crops. On such soils All
ammoniated superphosphate is all that is at
present required, and on these soils wood
ashes is found to be of little service as a fer
tilizer. But on our lighter or sandy Soils it
commonly happens that the stock of pot
ash is the first to give out, and here we often
see wonderful results from the application
of ashes, at least for while. OF course, as
ashes is not a complete fertilizer, or manure,
the use of ashes alone, for series of years.
exhausts the phosphoric acid and the nj
trogenous matter, and then the crops fail
In this case, where it is often said that the
land is "run out by using too much ashes"
it is not the excess of potash, but the de-
ficiency of phosphoric acid, or of nitrogenous
matter, or both, that causes the crop to fail.
1t should be borne in mind that, as almost
every tillable soil has large quantity of
navaiable-that is nSoiuble-potash in it,,
there may be, and often are, methods of
making this potash soluble, that are quite as
good, and possibly cheaper, than the direct
application of a fertilizer containing potash.
Among these methods are thorough tillage,
and also undertaking both of which have
an effect to render the potash of the soil
soluble. The blowing under of green ma
pose the soil and set potash free. And
finally the application of ground gypsum, or
plaster, rock containing large amount of
sulphuric acid (oil of vitrioD, seems to ex-
ercise a solvent power over the potash of the
soil, so that plaster is often very good sub
stitute for ashes, though it contains no pot
ash itself.
1t is of Importance that every farmer
should know whether his land is benefited
by the use of ashes, or any other potassic
fertilizer But usually it is all guess work
Men hear that ashes are very beneficial, and
they put them on, and we have known some to
spend good deal Of money in this way
without any advantage. The method OF
testing, or asking the SOIL" as described
in our previous article, will enable us to ar
rive at satisfactory conclusion on this, as
on other similar questions. But the very
fact of knowing that potash sometimes doe.
good, and sometimes does no good ano
knowing also why it is so, is a practica
guide to the observing farmer, by means Of
which he can often get at the truth without
direct test or experiment.