The Middlebury register. [volume] (Middlebury, Vt.) 1850-1882, 1876-11-25
agricultural department.
CONDUCTED BY ALBERT CHAPMAN.
Commercial Fertilizers.

marks are trOin cifOui"i i"teiy 'oo"S"
by the Agricultural Experiment Sta
ton at Middletown, Connecticut;
The primary duty of the chemist is
to make analyses and experiments,
and to refrain from Offering practical
advice until his theories have sub
stantial basis of known facts. AT the
same time it may not be out ofthe way
10 offer a few suggestions for the
thoughtful consideration of Connect
tiout farmers.
In saying that no plant can grow, no
crop can flourish without an available
supply in the soil of a sufficien guam.
tity of each one of a certain list Of sub
stances needful for its food, and that
the essential use of commercial fertili-
zers is TO supply food which plants
need and soils fail to furnish, we are
simply repeating universally admitted
facts. 1t Is perfectly plain, then, that
those commercial fertilizers will be
most economical which, in one way or
another, supply these lacking materi-
ais in the needed proportions and the
best forms, at the lowest cost.
We have, therefore, two most import
ant problems to solve. First, what ma
terials do our soils lack second by
what applications of fertilizers or other
means will their need best be sup
piled?
To answer either Of these questions
fully and definitely, is very difficult /;
the first because of the difference in
soils, and both because we do not
know, and do find it slow work to dis
cover definitely the ways in which at
mosphere and soils and fertilizers sup
ply food, and plants use it.
1t Is sufficiently well settled that nj
trogen, phosphoric acid, potash, sui
phurio acid, lime and magnesia are the
only ingredients of plant food which
need to be supplied in fertilizers. The
other materials, as iron, silica and
chlorine, which plants remove from
the soil, are, in so far as they are neg
essary for plant-food. furnished in
abundance by every ordinary soil.
Generally speaking, we may accept
the opinion commonly held, that mag
nesia may sometimes be lacking, that
sulphuric acid and lime are more, and
nitrogen, phosphorlc acid and potash,
most apt to be deficient in our ordinary
soils. In one soil, one, in another, sew.
eral or all. of these may be wanting.
1t was once thought that the chemi-
cal analysis of a soil would easily reveal
Its deficiencies in plant-food. But later
experience has shown this is at best a
costly and defective source ofinforma-
ton. Different samples of soil from
the same field may vary widely in
composition, and what is a still greater
difficulty, the chemical tests which
make known the presence of a given
ingredient in the soil do not show
whether it is in such O form that the
plant can use it. And there are many
processes of vital Importance TO the
sustenance of the plant, which are con-
tinually going on in the soil, but which
the analysis does not reveal.
Most of our artificial Inanures are
only special fertilizers. Guanos, phos-
pilates, fish and bone manures and the
like, contain mare or less nitrogen,
phosphoric acid and lime ; the super
phosphates contain sulphuric acid also.
With the exception Of some to which
the German potash salts have been adj
ded. very few of them contain any APP
preciable quantities of magnesia or pot
ash. They supply part but not all the
materials which soils may lack.
Many farmers find that guano, fish
and other special fertilizers whose &C.
ton Is quick and stimulating, seem to
leave their soil in more exhausted
condition than before they were APP
piled. And the complaint is not un.
common that such fertilizers do not
bring the same return as formerly.
May we not at least question whether
the immediate effect of these special
fertilizers has not been, in many cases,
to aid the plant to use the more availa-
BILE stores of food in the soil, until these
latter become so far exhausted as no
longer to respond to the stimulating
action of the special manures?
1t the above superstition be correct,
1t is clear that what such exhausted
soils need, is something to supply, not
only the nitrogen and phosphoric acid
Of the guano, or fish. or bone, or SUPER
phosphates, or other special fertilizers,
but also the potash and other minerals
that these latter do nOt furnish.
Ashes are, for many soils, standard
fertilizer. Places where q tree or a
brush-heap has been burned, often
show the effects of the manuring for
years. 1t is trite saying, that 1.-THE
land never forgets ashes" Ashes sup
ply directly all the soil ingredients OF
plant food except nitrogen. Their in
direct action is also, very likely, not
unimportant in rendering other mate.
rails in the soil available. Instead of
wearing out soils, they strengthen
them. May not this difference be due,
in part at least, to the fact that they
furnish the other ingredients of plant
food that the guano and fish lack?
Stable manure furnishes all the In.
gredients of plant food. 1t is com.
plete fertilizer. Farmers do not COM
plain that 1t helps to exhaust theli
land.
There are soils which, by applica-
tions of nitrogen and phosphoric acid
in the form Of guano, bone or nitrogen.
Gus superphosphates, may be made Ia
bear good crops year after year, They