The Butler weekly times. (Butler, Mo.) 1881-1918, 1911-09-21
BACTERIA AIDS ALFALFA
NODULES FIX NITROGEN IN
AVAILABLE FORM.
BY N. F. Miller, College of Agricul.
ture, University OF Missouri.

The alfalfa plant, in common with
all legumes, bears upon its roots the
nodules inhabited by class OF bac-
terra which have the power OF fix
ing within their bodies the free gas
eous nitrogen of the air, in q form
available TO plants. On soils poorly
supplied with this element Chat is,
those containing an insufficient
amount OF decaying vegetable mat
teri these bacteria seem to be essen
plant. II the soil is rich in nitrogen,
so that the alfalfa plant can secure
sufficient quantity from this source
these bacteria do not seem to be cs-
sential. Since most soils do not con-
tain a sufficient amount of this ele-
ment, however, the presence of these
particular bacteria is important, and
as result much has been written
regarding the value and necessity Of
inoculatins soils on which alfalfa is
to be grown.
The matter of inoculating is merely
the introduction into the soil of the
bacteria of the particular kind that
are adapted to the legume which one
wishes to grow. 1t may be accom-
plished in different ways. One meth
ed is by taking soil from a field al
ready successfully growing this par
ticular legume and scattering on to
the field which it is desired to inocu
late. The bacteria are thus trans
ferred from one field to another in
the soil. Another method is by what
is known as pure culture" of the
bacteria, in which cases they are taken
from the nodules Of healthy plants,
developed into very large numbers in
some suitable medium and then
transferred either to the seed before
planting or they are mixed with soil
which is then scattered over the field
to be inoculated. Various methods
have been devised for transporting
these cultures long distances, but the
one most practical seems to be that
of transferring the bacteria in dor-
mant form from the laboratories to
the man who wishes to use them and
allowing him to grow them to large
numbers in a solution which is read
lily prepared from material sent with
the bacteria. This solution is then
either sprinkled over the seeds so as
to moisten all of them or it is sprin
Killed. on small amount (about 100
pounds) of soil. which is then mixed
with larger amount and scattered
over the field.
The most certain method of inocu.
lation seems to be by means of soil.
This is accomplished by taking soil
from a field where alfalfa has been
growing we'll for two or more years
and scattering it over an area to be
inoculated The soil for this purpose
should be taken to the depth of six
or seven inches, scattered on with a
shovel and narrowed in. This will
necessitate the ground being in good
condition at that time i'm order that
the infected soil may be we'll worked
in. 1t is necessary to do this at once
after scattering, since few hours
exposure to the sun either kills the
bacteria or so weakns them as to
interfere with their proper growth.
The amount of soil to use will vary
from 300 to 1000 pounds per acre,
depending upon the manner of appli-
cation IF it is simply scattered on
with a shovel the larger amounts ara
usually necessary in order to make
tho soil cover the acre evenly. If it
is necessary to ship soil long dis
tances. however. two or three hun
drea pounds may be mixed with a
LARGO amount of soil from the field 10
be inoculated and thus more easily
made to cover an acre. A small
amount Of soil may also be used in
this way by drying il away from the
sun. sitting and putting it In with the
~ TN, dill