The Laurens advertiser. (Laurens, S.C.) 1885-1973, 1895-02-26
Build up Your Lands.
DEAR SIR.

will change their minds when the
planting season arrives, for it has been
demonstrated that fertilizing is abso-
lntely necessary to our soil; but ]
would advise our. farmers to plant less
land, and fertilize freely, for It pays;
plow up the surplus land and put in
about five hundred pounds mari to the
acre; sow these lands in leguminous
plants for green manuring and for feed
ing. This would put the lands in fine
condition for raising the crop next sea-
son, without other fertilizer.
The us. Department of Agriculture
says, green manuring or blowing under
green crops raised for that purpose, is
one OF h oldest means of Improving
the fertility of the soil. 1t was advo-
Gated by Roman writer's more than two
thousand years ago, and from that time
until now 1T has formed a most impor-
tant resource of the farmer, especially
where the supply of barn yard manure
Is insufficient. Its advantages are
many. The more striking are, that it
furnishes the surface soil with a supply
OF the fertilizing materials needed by
crops, increases the humus, and i'm
proves the physical qualities and the
filth OF the soil. AS a humus former,
green manuring stands next to barn
yard manure.
BY, means of green manuring, land
which is practically barren may be
brought up to a state of fertility where
1T Will produce profitable crops. AS q
single instance Of this, may be men
TONED the experiments carried on by
the Michigan Experiment Station on
the Jackson Plains OF That State. In
1883, experiments were undertaken on
the light sandy, almost barren, soils of
these plains. Green manures were used
mainly, supplemented by cheap fertil-
lzers. In three years marked improve
ment was evident, not only in the ply
steal character of the soil, but also in
the increased yields of various crops.
Again, green manuring may be used
to take the place of more expensive
fertilizers and manures on soils already
under cultivation. 1t is in this latter
use that it finds its widest application.
There has been much speculation as
to the manner in which the crops COM
monty used for green manuring could
gather such large quantities of fertiliz-
ing. 1t will be remembered, that the
principal fertilizing ingredients re-
CURED by plants are nitrogen, phos-
phoric acid and potash. These are
each, n all moro or less, essential to
the healthy growth of crops. Conse-
quently they are applied to the soil in
the form of commercial fertilizers and
other manures. In attempting to ex-
plain how the fertility of the soil is
maintained by green manuring, it has
been said, that plants with long roots,
like %clovers, feed deep down in the soil
or subsoils on materials beyond the
reach of surface feeding plants: and
that when the tops of these plants die
down and are mixed with the surface
soil, they enrich it much the same as
an application Of barn yard manures.-
This is undoubtedly true, but it fails to
explain how sch large quantities of
materials a be obtained, especially
when clover is grown continuously for
a lumber of years. The question has
finally been solved by II of the most
interesting and important discoveries
yet made in agricultural science. 1t
has been found that certain plants can
feed upon the nitrogen in the atmos-
phere. They take their phosphoric
acid and potash from the soil, but they
obtain their nitrogen very largely from
the air. Hence they draw from the air
a material necessary to the growth of
crops, which inthe form of commercial
fertilizers, as nitrate of soda, ammonium
sulphate, dried blood, etc, is paid for
at the rate of from ID to 20 cents Il
pound.
iioW IlLANlS GEL NlISOGEN FlSOM
THE AIR.
The air We breathe is about four
iifths nitrogen and one-fifth
We use the oxygen in breathing but
discard the nitrogen. 1t has been re-
gardcd merely as a material for dilut-
ing the oxygen, which would otherwise
be too strong for our use. All attempts
to economically render this nitrogen
OF the air available for plant food, by
chemical means, have been u~nsuccess-
full. Recently it has been discovered
that the sO-called, leguminous plants
clover, peas, beans, lupines, vetches,
ctc., a take up this nitrogen of the
air and can grow without being ma
nured with phosphoric acid and potash.
The name in which this nitrogen as
sanitation takes place has been care
fully and patiently studied by scien-
fists, and although the details are not
fully understood, the primary cause has
been found. 1t is believed that plants
are enabled to get this nitrogen through
the activity of the lower forms of life,
bacteria or microbes, which can only
be seen with the aid of a powerful mic
roscOpe. These organisms live in Vie
soil and are to be found where lcgumi
nous plants have been grown. They
produce, or cause the plants to produce,
little nObules, or tubcrcules, on the
roots. 1t is through these tubercules
that the plant gets it's atmospheric
nitrogen. The air enters the soil by
the numerous pores or openings in it,
which are produced by blowing, cult
waiting and working the soil, by decay
of rootlets, by earthworms, etc. BY
just what physiological processes the
nitrogen assimulatiOns takes is a qucs-
ton still in dispute among SCIENTISTS
1t is sufficient for practical purposes
to know that nitrogen is taken up from
the air by the growing plant, directly
or indirectly, and that this nitrogen
assimilation takes place as a result Of
the life of bacteria. 1t is a peculiar
fact that few, if any, root tubercules
are formed whom leguminous plants are
manfred with nitrogen: the plants
must first hunger for nitrogen before
the t~ubercules are formed, and the
presence of tubercules indicates that
the plants are taking nitrogen from the
air.
Now, curious as it may seem, there
appears to be different forms of bacte-
ria for different kinds OF plants. Hence
it sometimes becomes necessary to
provide crops with the necessary bac-
terra before they use the nitrogen Of
the air. This is done by applying Il
a light dressing of soil in which the
kind of plants it is wished to grow have
been previously grown. This is called
incubation. 1t is sometimes necessary
in growing a crop on u piece Of land