The Manning times. [volume] (Manning, Clarendon County, S.C.) 1884-current, 1895-03-13
GREEN MANURING.
A VERY INTERESTING ARTICLE ON
THE SUBJECT

ments at Several Agricultural Stations.
We hear in all directions that the
farmers will not use fertilizer this
year. We know very we'll that they
will change their minds when the
planting season arrives. for it has been
demonstrated that fertilizing is abso-
lutely necessary to our soil; but l
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 iegumlnous
plants for green manuring and for
feeding. This would put the lands in
fine condition for raising a crop the
next season. without other fertilizer.
The Z. S. Department of Agriculture
says, green manuring or plowlng un-
der green crops raised for that purpose
is one of the oldest means Of lmprov-
ing the fertility of the soil. 1t was adj
vocated by Roman writers more than
two thousand years ago, and from that
time until now it has formed a most
important resource of the farmer, es-
pecially where the supply of barnyard
manure is insufficient Its advantages
are many. The more striking are.
that it furnishes the surface soil with
supply of the fertilizing materials
needed by crops, increases the humus,
and improves the physical qualities
and the tilth of the soil. As humus-
former, green manuring stands next to
barnyard manure.
By means of green manuring. land
which is practically barren may be
brought up to state of fertility
where it will produce profitable crops.
As a single instance of this, may be
mentioned the experiments carried on
by the Michigan Experiment Station
on the Jackpine Plains of that State.
In 1888, experiments were undertaken
on the light, sandy, almost barren
soils of these plains. Green manures
were used mainly, supplemented by
cheap fertilizers In three years mark
ed improvement was evident, not only
in the physical character of the SOL,
but also in the increased yields OF the
various crops.
Again. green manuring may be used
TO take the place CT more expensive
fertilizers and manures on soils al
ready under cultivation. 1t is in this
latter use that it finds its widest appll-
cation.
There has been much speculation as
to the manner in which the crops
commonly used for green manuring
could gather such large quantities OF
fertilizing materials. I: will be re-
membered, that the principal fertiliz-
ing ingredients required by plants are
nitrogen, phosphoric acid and potash.
These are each and all more or less.
essential to the healthy growth of
crops. Consequently they are applied
to the soil in the form Of commercial
fertilizers and other manures. In at
tempting to explain how the fertility
Of the soil is maintained by green ma
ruring, it has been said, that plants
with Iongroots, like clovers, feed deep
down in the soil or subSoil on materi-
ais beyond the reach of surface feed
ing 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
BARNARD manures. This is undoubt-
edly true, but it fails to explain how
such large quantities of materials can
be obtained, especially when clover is
grown continuously for number OF
years. The question has finally been
solved by one 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 atmosphere and store
it up in their tissues as they grow:
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 in the form of CONNER
cial fertilizers, as nitrate Of soda, am
monum sulphate, dried blood, ETC., is
paid for at the rate of Is to 20 cents a
pound.
The air we breathe is about four
ffths nitrogen and one-ffth oxygen.
We use the oxygen in breathing but
discard the nitrogen 1t has been re-
garded merely as a material tor dllut-
inc the oxygen, which would other
wise be TOO strong for our use. al
attempts to economically render this
nitrogen of the air available for plant
food, by chemical means, have been
unsuccessful. Recently it has been
discovered that the so-called leguml-
nous plants-clover, peas, beans, lu-
pines, vetches, etc., can take up this
nitrogen Of the air and can grow with,
out being manured with nitrogen II
manured with phosphoric acid and
potash. The manner in which this
nitrogen assimilation takes place has
been carefully and patiently studied
by scientists, and although the details
are not fully understood, the primary
cause has been found. 1t is believed
that plants are enabled to get this nj
trogen through the activity of the low
er forms OF life, bacteria or microbes.
which can only be seen With the aid
of a powerful microscope. These Or
i canisms live in the soil and are to be
i found where leguminous plants have
been grown. They produce, or cause
the plants to produce, little nobules,
or tubercules, on the roots. 1t IS
through these tubercules that the
plant gets its atmospheric nitrogen.
/ The air enters the soil by the numer,
Gus pores or openings in it, which are
nroduced bv blowing, cultivating and
:, working the soil, by decay of rootlets,
by earthworms, etc. By just what
physiological process the nitrogen as
simulations takes place is a question
still in dispute among scientists. 1t Is
sufficient for practical purposes tc
know that nitrogen is taken up from
the air by the growing plant, directly
: or indirectly, and that this nitrogen
assimilation takes place as result OF
the life of bacteria 1t is a peculiar
: fact that few, if any, root tubercule:
are formed when leguminous plant:
o,,a ,,,ao1,re6 with NITROGEN: the plant!