The Savannah morning news. (Savannah, Ga.) 1900-current, 1902-11-24
Velvet Beans ms Soil Renovator.

The velvet bean derives it's nitrogen
from the air, says the Florida Agricul-
turist. This power is not common TO
all plants, but is confined to the plant
known as the legumes, and is made
| possible through the agency of micro
organisms which live on the roots of
these plants and by some obscure pro-
cess convert the nitrogen of the air
into a form available to the plant in
which it is stored up. Nodules varying
in size are produced on the roots of
these plants by these bacteria
The roots and stubble contain a con-
siderable portion of the nitrogen OBJ
tanned from the air and as they are
left in the soil decomposition gradual
ly takes place and the nitrogen thus
becomes converted into a form that is
available to those plants which do not
have the power of obtaining a supply
directly from the atmosphere The
whole of the nitrogen obtained from
the air by a crop of velvet beans is by
no means left in the roots, but the
greater portion of 1t is stored up in
the leaves, vine, and seed, though the
soil gains much of this from the leaves
which are shed by the plant. If so
desired the entire plant may be left
to decay on the surface and turned
under the following spring, but, it is
not advisable to turn under the green
vine as it will cause the land to become
sour and this will have to be correcte
by an application of lime, 1t is not
even profitable to let the plant die
down on the surface and subsequently
turn it under, inasmuch as the hay
which may be made from the vine is
much more valuable as a food than
the vine is worth as a fertilizer. Be
sides, If properly managed the fer
tilizing constituents of the hay may to
large extent. be saved in the form
of manure. In order to form an esti-
mate of the quantity of nitrogen which
may be procured from the air through
the use of the velvet bean, the root
from a vine was carefully removed
from the soil, dried, weighed and an
alyzed. The results were then calcu-
lated to the basis of one acre 1t was
found that on one acre $50 pounds of
dried root would be produced. This root
contained la per cent of nitrogen, so
from the root alone 81 pounds of nj
trogen would be added to an acre of
ground.
This could not be considered a fair
index to the weight of nitrogen added
inasmuch as most of the nodules had
already decomposed when the root was
collected and the nitrogen from these
is not included in the estimate The
quantity of nitrogen was also esti-
mated which was removed in the hay
from an acre.
Weight of green vine on an acre, 81
1872 pounds.
Weight of dry hay, 1858 pounds.
Percentage of nitrogen in hay, 2.21.
Weight of nitrogen in the hay, 1915
pounds.
In this way it is shown that a crop
of velvet beans on one acre, after
yielding three tons of hay, supplies 81
pounds OF nitrogen to the soil uuan-
tity which is usually sufficient for the
Following crop. II on the other hand
the hay is turned under after drying,
an acre of land would have it's nitro
gen increased by 1912 pounds 1t
would then be unnecessary to add nj
trogen to land so treated for several
| years. The entire amount of nitrogen
saved in this manner represents a cash
value of from SIS to SIS.