Vermont phÅ“nix. [volume] (Brattleboro, Vt.) 1834-1955, 1883-02-23
Agricultural,


the exception Of two or three. The two sub.
stances soonest exhausted, or most likely tc
be deficient in unfertile soils, arc potassium
and phosphorus The former enters into
the composition Of plants in the form Of a
carbonate or as potash the latter in comb.
nation with oxygen as soluble phosphoric &C
id. Nitrogen in some Of its combined forms,
asn ammonia, is also essential to fertility. But
chemistry has not yet shown exactly how
plants obtain nitrogen whether directly
from the atmosphere, four-ffths of which is
nitrogen, or through the medium Of the soil
by way of the roots, or from both sources.
This is an important question as bearing upon
the restoration Of exhausted soils and the val.
ne Of heterogeneous matter, which is the most
expensive part of all complete fertilizers.
The recent experiments of DR.. j. b. Lawes
of Rothamsted, England tend to show that
the nitrogen of plants is derived mainly, If
not entirely, from heterogeneous matter within
the soil This is at variance with what agri-
cultural chemists have taught and still teach.
Liebig held that nitrogen was absorbed from
the atmosphere through the leaves Of plants,
and that the amount of nitrogenised products
which could be obtained from a given sur
face OF land was in proportion to the extent
Of leaf surface, the leaves being the organs
of absorption, and to tho time in which these
organs were in a state of activity. If one
plant possessed twice as much leaf surface as
another, he taught that it would, during the
same period Of vegetation, extract double
the quantity of nitrogen from the air-an ov-
ident mistake, allowing that the leaves absorb
nitrogen. But according to Liebig, plants
derived their nitrogen not exclusively from
the leaves but partly from the soil.
NJ. Vile, an eminent agricultural chemist
of France, says that crops always yield more
nitrogen than is supplied in tho manure and
that this excess is derived, not from the soil,
but from the atmosphere. He shows that
the amount of combined nitrogen existing in
the air as ammonia and nitric acid is very
small and that plants cannot get more than
d pounds Of combined nitrogen per acre an
nually from rain hence the source must be
the free nitrogen of the air. Certain classes
of plants, as clover, peas beans, etc, he con-
cludes take practically the whole of their nit
rogen from the air, aud that others, such as
the cereals, obtain their principal supply
from the soil through the roots.
Prof. S. W. johnson says that though a
large proportion Of the air consists Of nitro
gen, and nitrogen is essentiato plant growth,
plants are unable to take it from the air The
nitrogen must be in combination not pure as
in the air, before plants can assimilate it.
When in the form of ammonia, nitric acid,
nitrate of soda or nitrate of potash, nitrogen
can be taken by the plant. Prof. Collier,
chemist of the department of agriculture
also says that nitrogen, though constituting
about four ffths of the atmosphere is never
theless useless to the plant in this condition,
since the plant is able to make use only OF
compounds of nitrogen, and it is often found
that most beneficial effects follow the appli-
cation of some heterogeneous fertilizer In a
later article Prof. Collier seems to admit i
doubt as to the absorption of free nitrogen
from the air in the following language 1T
is not proven, and it seems very doubtful,
whether any part of the nitrogen absorbed
and assimilated by plants is derived directly
from the free nitrogen of the air. On the
other hand, abundant evidence exists that
ammonia, or any substance that can furnish
it, and nitrates have direct and positive eff
fects for good on growing plants No plant
has ever been examined which did not con.
tain greater or lesser proportion of nitro
genous constituents in all stages of its devel.
opment and in all its essential organs
1t will be observed that some of the con-
illusions of these eminent chemists aie quite
4 II. I'M.
pears to be that none of them yet know ex-
actly what Office the leaf and what the root
performs in furnishing the substance of the
plant.
In ninety-six trials, made in several differ
ent states, as reported by Prof. W o. Atwa-
ter, the use of nitrogen as part of fertilizer
increased the corn crop enough to pay its
cost in only thirteen cases. Experiments
were made few years ago by Col. J.B. Mead
of Randolph to test the effect of mineral fer
tilizers alone-superphosphat and muriate of
potash-and of the same with nitrogen in
different amounts and forms. The result was
that in seven cases out of nine the yield was
better with the mineral fertilizers alone. In
the two cases where the addition of the nitro
genous fertilizer made an increase, it was
not sufficient to pay the cost. Other expert
ments made in 1878 and 1879 by several far
mers of this state, under the direction of the
agricultural college, gave better results from
the use of nitrogen but the crops were not
generally, with the exception of oats, in
creased enough to pay for its extra cost,
while phosphate and potash usually paid their
cost in the increase of the crop.
The secretary of the state board of agri-
culture Dr. Cutting, in his lecture on plant
Growth and Fertilization" says: 1.-The plant,
the stalk of corn or grain, is composed of
some thirteen different materials, and yet on
ly from one to five per cent. comes from the
earth, This is true, and OF the sixty-fve el
ements existing on the earth, the plant is in re
ality mainly made up ofthirteen. Occasionally
others are found, but the clements that arc
considered essential are carbon, oxygen, by.
drogen, nitrogen, calcium. magnesium, po-
tassium, sodium, iron, sulphur, phosphorus
silicon and chlorine The first four, which
constitute the bulk of the plant, are as be
lieve wholly obtained from the atmosphere
Yet many pretend to supply nitrogen through
heterogeneous material but l do not believe it
usually necessary to spend money in that di-
rection"
We can hardly believe that DR.. Cutting
means to deny that plants obtain nitrogen
from its combinations in the soil He doubt
less only means to assert that the air is the
ultimate source of all nitrogen which enters
into the composition of plants. In any 9th.
er sense, the belief that the nitrogen of
plants is derived wholly from the atmosphere
would be contrary TO the authority of the
chemists. OF the use of nitrogen as a fer
tilizer, DIR. Cutting says it has never paid him
half its cost, and it has at best a very doubt
fulvalue, while it is by far the most costly in.
gredient in what are called complete fertil-
izers. What Vermont farmers should usually
purchase is phosphorc acid and potash. He
quotes Prof. Ssnborn as having O similar ex-
perience in the use of heterogeneous fertilizers
on the New Hampshire agricultural college
farm.
The Boston journal thinks that the cry that
the duty on lumber should be taken OF in or.
der to save our forests is rather absurd, to say
the least so far as the numbering states of
New England ara concernad II 10 not tbo