The Abbeville press and banner. [volume] (Abbeville, S.C.) 1869-1924, 1922-01-18
SOIL NITROGEN
How it is Conserved and Replenished
By Nature.

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consider how very easy it is for
nitogen to escape from the soil it
is hot surprising that it is the high
est priced of all fertilizing materials.
Even at that, however, the price is
higher than it need be, for nature
manages to maintain the supply in
every tract of wild land without i'm
porting fertilizers from abroad, and
we would profit by adopting more Of
Natures methods.
Nature uses two methods for
maintaining the supply. First, she
conserves. Whenever a leaf becomes
of no use to tree it is shed and
falls to the ground. Similarly, other
waste materials fall to the ground
and become part of the soil. Stated
briefly. Natures method of conserv-
ing nitrogen is to return all waste
materials to the soil very soon after
they become wastes. This feature
has great deal to do with her
ability to increase the fertility of
the soil which runs wild.
But even nature is unable to re-
turn all of the nitogen to the soil
in shape to be of use to plants. There
Is inevitably some loss even here.
Consequently she must have some
means of replenishing the soil supply
or eventually the soil would be COM
pletely exhausted This replenish-
ing is accomplished chiefly by GER
tain lowly plants, which. have. the
unusual ability of taking nitrogen
from. the inexhaustible supply in the
air and using it in the same way
that other plants use the soluble
supply in the soil. When they die
I most of the nitrogen thus secured
from the air is added to the soil.
These are said to be "nitrogen-fiix-
ing" plants; and the most important
ones from this standpoint are certain
bacteria. -.
There are two general types Of
bacteria which "fix" nitrogen. The
bacteria of one type live in ordinary
soils. The other type comprises the
'1egume" bacteria, or ''nodule" bac-
terra, so-called because they grow in
the roots of legumes (clovers, beans,
peas, etc. and cause round gals or
nodules to develop. This method of
growth is mutually favorable, for
the legume furnishes a good place to
grow and food of one kind to the
bacteria and the bacteria furnishes
nitrogen to the legume. The amount
of nitrogen so furnished is often very
great, as may be observed by noting
the difference in size of legumes
with and without nodules on soil
poor in nitrogen. And the amount
of nitrogen available for succeeding
plants where legumes are returned
to the soil is also very great, as may
be observed by planting crops after
legumes have been plowed under.
This is the most important source
of nitrogen for the soil, either in
nature or under cultivation.
A small amount of combined or
@fXed" nitrogen is added to the soil
III rain water and snow, but the
amount is comparatively unimpor-
tant.
Farmers have still another method
not used by nature, by which they
can increase the nitrogen supply.
: They can apply commercial nitrogen.
This is expensive but has special
value under some circumstances, and
should be used in most cases to sup
plemeat and not to take the place Of
S the other sources mentioned.
The most effective measures for
maintaining soil nitrogen on the
farm as Well as in nature, are careful
conservation, utilization of the work
of soil bacteria, and utilization of
the work of legume bacteria. And
the legume bacteria are the most i'm
portant of all.
Hor Idea Of It.