Lincoln County leader. [volume] (Toledo, Lincoln County, Or.) 1893-1987, 1912-02-16
FARM AND AM! ORCHARD
Notes nd Instructions from Agricultural Colleges and Experiment Stations
Washington Speiouy

fact that certain diseases of the
grape had been killed out of the soil.
That without doubt was one very
important result of the treatment
However, subsequent investigations
have shown that it was due to the
fact that the germ balance in that
soil was broken up by the destruc-
tion of certain kinds of bacteria
which are inimical to the growth of
those which produce the greatest de-
gree of fertility, thus these other
forms had a more favorable oppor-
tunity for growth and the soil imme-
diately became more productive.
Such conditions held for some months,
until the other kinds of germs had
had opportunity to get back into the
soil again from the surrounding
areas. Such a method of treatment,
however, is not at all economical for
general cultivation.
Moisture likewise is another import
ant factor. AS a general law it is
stated that bacteria require 80 per
cent of water in their surrounding
medium in order to grow. Thirty per
cent of moisture in soil would be
very excessive, but we must remem.
ber that various soil particles are
covered over with very thin layer
of water which is known as hygro-
scopic moisture, and though this layer
of liquid is so very thin it is quite
enough to sustain the germs In
practice we find that where the
amount of moisture falls below this
point preservation itself fails, by
which we mean that growth of bac-
terra is stopped Cereal grains. are
preserved indefinitely as long as they
are kept dry BECAUSE there is not
enough moisture there for the growth
of bacteria which would spoil the
grain; as soon as it gets wet and
soaks it changes rapidly and becomes
worthless because of the action of
certain bacteria, which are not de.
sired in that particular instance. In
order to reduce the amount of mois-
ture and also to increase the number
of air spaces so that there may be
a greater supply of oxygen in the soil
a farmer then has to drain his soil
as the excess of water makes it heavy
and consequently unfertile.
Another condition which must be
looked out for in order that bacteria
may produce the most favorable re-
suits in soil is to keep the soil as
open as possible and yet so cultivated
as to retain the soil moisture. An
open soil is one which contains a good
deal of air. Air Is necessary to bac-
terial growth of the favorable kind in
soil because of the fact that it con.
tains one-fifth part of oxygen, and
bacteria thrive much better in the
presence of this element. The nitro.
gen which Is in the air and which
makes up four-fifths of the ordinary
atmosphere is in this condition mere
ly an inert diluting medium for the
oxygen in its relation towards most OF
the bacteria of the soil. Because OF
the fact that air is necessary and
most favorable to bacterial growth II
is then easy to see why certain kinds
of beneficial soil bacteria are much
more active in sand than they are in
a heavy clay. In certain parts of oul
state we find that loose sands are
most exceedingly fertile and this is
due particularly to the fact that they
because of their texture, have fur
thered the growth of bacteria normal
ly present in them, and these bacteria
convert the insoluble plant foods into
a soluble condition so that they may
= be used to better advantage by plants
The fact that free circulation O
air in the soil Is interrupted by {
number Of factors in the lower depth.
of the soil, but particularly by friction
and by the water table, brings us II
an understanding of the well known
. fact that the steadily lessening growth
of bacteria is found in the uppe
three feet. The most numerous lif'
lies from two to six inches below'th'
surface, and below this point ther'
is gradual diminution in the mum
bers present so that below three fee
the number is very small.