The Democratic advocate. [volume] (Westminster, Md.) 1865-1972, 1894-12-01
Ghe Sarmer.
The Vaccination of Land,
rrom the American Architect.

The Vaccination of Land.
From the American Architect.
Some of the most extraordinary agricul-
tural experiments ever undertaken, con-
sidered both practically and scientifically,
are described in lie Genie Civil. Every
one who has ever owned lawn knows that
to pillow the ground at intervals, and raise
a crop of certain vegetables, improves the
subsequent growth Of grass; and drive
through the suburbs of any large city will
show lawns undergoing this treatment,
sometimes with a crop of potatoes, some
times with beans, according to the notions
of the owners, or their gardeners. The
process by which this alienation of crops
improves the soil has never been very
clearly explained. Most people suppose
that the repeated digging up of the earth,
to plant the potatoes, and harvest the crop,
is the secret of the success Of the treatment,
but chemists have fancied for many years
that. in such rotations of crops one set of
plants might have the power of absorbing
nitrogen from the atmosphere, and convey
inc it to the soil. With this idea, long
series of experiments was carried out fifty
years ago, by the greatest chemists in Eu
rope, who analysed various plants, the air
in which they grew and the soil, before
they were planted, during their growth,
and afterward, and came to the unanimous
conclusion that the absorption and storage
of nitrogen by growing plants was an i'm
possibility.
For all this farmers continued to observe
that certain plants, particularly Of the leg
luminous tribe. such as clover, lucerne,
sainfoin. and some others, instead of ex
hausting the soil. seemed to enrich it, so
that, even after the leaves and stems had
been cut and carried away, the roots alone,
left in the ground, sensibly increased its
fertility Analysis showed that these roots
contained considerable quantity of nitro
gen If, according to Boussingault, Lawes,
Gilbert and Others, it was impossible that
this nitrogen should be derived from the
atmosphere, it must be drawn from nitro
genous matters in the soil The inference !
would be, in this case. that heterogeneous !
manures would be beneficial to crops re-
quiring so much nitrogen for their growth;
yet it is well known to farmers that these
plants not only derive no benefit from nj
trogenous fertilizers, but are injured by
them, while, although through the nitrogen
contained in their roots they improve the |
soil greatly for succeeding crops of other /
plants. they injure it for themselves; and
legumiuous crops, cultivated too long in the
same ground become sickly. 1t was not
until few years ago that science and OBJ
servation were reconciled, by the persistent
investigations of NM. Hellriegel and Will
farth who demonstrated beyond question
the fact that the leguminose do, in grow
ing, absorb large quantities of nitrogen
from the air but with the singular condi-
ton that the absorption of nitrogen begins
only with the appearance of a diseased
state, which is marked by the development
of tubercles, about the size of millet seed
on the roots, and is, apparently, caused by
minute animals which are always found in
the tubercles, and seem to give the plant
the nitrogen absorbing power. Further
investigations showed that the young,
healthy plants lived on the nitrogen already
contained in the soil. and that it was not
until this was exhausted, and the plants
began to suffer, that the nitrogen absorbing
excrescences made their appearance; and
proved. also, that the tiny inhabitants Of
the tubereles were, as rule, confined TO
one species of plant, the acacia microbe,
for example, refusing to live on the bean.
or the clover microbe on the lentil
1t is evident that plant capable of alb
sorbing nitrogen, which is costly as well
as indispensable adjunct to farming, and of
storing it up in the soil for its master
profit, is "a valuable possession; and, as only
diseased plants have that property, it is
obvious that it is desirable to spread the
nitrogen storing disease With this view,
several skillful farmers in France and Ger
many have, within the past two or three
years, been trying experiments, by wac
chatting, as they say, fields of leguminous
plants, by sprinkling them with earth. in
which tuberculous plants have been grow
ing. or water in which they have been
anu btlC ACSuNo nave bCOu OAtidoi-
binary. Analysis has shown that a single
crop of tuberculous leguminOse, if thetops
are plowed in, adds to the soil from FIVE to
twelve thousand pounds of nitrogen, worth
from eighteen to forty-fye dollars, to the
acre; and even when the tops are cut and
carried away, there is enough nitrogen left
in the roots to insure good crop of cereals
on the same ground the next season, with
out other fertilizer. In 1890, tract of
old, peaty soil was ''vaccinated with a
ton and half to the acre of earth from
diseased field Besides this. FIVE hundred
and twenty pounds to the acre of scorie
from dephosphorating furnace were spread
over the ground, and about thousand
pounds to the acre of kainite, but very little
nitrogenous manure. The tract was then
sown with clover, which produced nearly
three tons of hay to the acre The next
year, virgin peaty soil was treated with
half ton to the acre of sand, from field
which had borne crop of scrabble,
a small leguminous plant, unknown to us.
The sand was narrowed in. No other ma
nure Of any kind was put on. The ground
was sown with winter rye. In May, thir-
ty-fye pounds to the acre of scrabble seed
was sown among the rye. The rye pro
duced a good crop, and, after the harvest,
the scrabble, which had absorbed and
fixed about sixty pounds to the acre of at
mospheric nitrogen, was plowed in, as green
manure. The next year, the land was
planted with potatoes, and similar potatoes
were planted in neighboring fields, which
had not had the new treatment, but were /
simply enriched with barn yard manure !
AT the harvest, the yield from the vaeci-
mated fields, which had received no other
manure, was from twenty eight to sixty
two per cent. greater than from the ma ;
nured fields, according to the variety
planted. The most surprising result from
the treatment aDDeara however IN have e