St. Tammany farmer. [volume] (Covington, La.) 1874-current, 1894-07-28
FARMER ANDPLANTER.
GREEN MANURlN0.

One Of the Oldest Known Methods Of IL
= proving the Fertility Of the Soil.
Green manuring, or plowing under
green crops raised for that purpose. is
one of the 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 it has formed q most i'm
portant resource of the farmer, es-
pecially where the supply of barnyard
manure is insufficient. Its advantages
are many. The most striking are that
It furnishes the surface soil with q
supply OF the fertilizing materials
needed by crops. increasing 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 q state of fertility where
1t will produce profitable crops. As a
single instance of this may be men.
toned the experiments carried on by
the Michigan experiment station on
the "Jack-pine 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 marked i'm
provement was evident, not only in the
physical 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 fer.
tilizers 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 materials. 1t will be remembered
that the principal fertilizing ingredi:
ents required 1y 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 one form of CONNER
cial fertilizers and other manures- In
attempting to explain how the fertility
of the soil is maintained by green ma
nuring it as been said that plants with
long roots, like clovers, feed deep down
in the soil or subsol on materials be-
yond the reach of the 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 barnyard
manure. This is undoubtedly true,
but it fails to explain how such large
quantities of materials can be OBJ
tanned, especially when clover is grown
continuously for number of years.
The question has finally been solved by
one Of the most interesting and i'm
portant discoveries yet made in agri-
cultural science. 1t has been found
that certain plants can feed upon the
nitrogen in the atmosphere and store il
up in their tissues as they grow. They
take their phosphoric acid and potasf:
from the soil, but they obtain their
nitrogen very largely from the air.
Hence they draw from the air q ma
terial necessary to the growth of crops,
which in the form OF commercial fer.i-
lizers. as nitrate of soda,. ammonium
sulphate, dried blood. etc. is paid for
at the rate of from fifteen to twenty
cents pound.-U. s. Department Of
Agriculture Bulletin. F1