St. Tammany farmer. [volume] (Covington, La.) 1874-current, 1903-03-07
FARMER ANDPLANTER.
WASTE OF PLANT FOOD.
Ii Can Not BE Wholly Prevented, But
May BE Mftfsated By Intellf-
gent Action.

All titled soils are subject to con-
slant waste Of the plant food ele-
ments; that is, nitrogen, potash and
phosphoric acid. Soils contain as a
natural condition, all shree of these
necessary substances, and potash and
the rocks which by disintegration
form the great bulk of our soils, and
the nitrogen in the form of vegetable
matter, the residue of plant growth.
A pure soil, of course, contains no
vegetable matter, but furnishes
medium for the growth of plants OF
the clover family, which have the
power, when supplied with potash and
phosphoric acid, of assimilating the
inert nitrogen Of the atmosphere.
The decay of the roots, etc., of this
class of plants supplies nitrogen for
the growth Of plants which can not
make their own nitrogen, so to speak,
and thus, step by step, we have the
agricultural soil of to-day. .-.
Plant food must be soluble in soil
waters before plants can make use
of it to accelerate growth, and 1T Is
in this point the greatest losses oc-
cur. For example, if more plant food
is made soluble than the plants in
that immediate spot can assimilate,
the quantity not taken up passes on.
with the drainage water, to be taken
up more or less by the feeding roots
of plants it meets in passing on to
the streams and water courses. More
or less fails to be utilized in this pur-
pose, and ultimately finds its way to
the ocean where it serves to grow
marine plants. Nitrogen is subject
to losses in addition to this. By the
action of certain bacteria, the nitro
gen in decaying vegetable matter is
converted into ammonia, which may
escape in the air as gas, or this am
mouia by the action of other micro
organisms may be changed back into
the inert form of nitrogen as found
in the atmosphere, and which is use
less as plant food.
A great deal may be done to lessen
these losses, though they can never
be wholly prevented. The heaviest
losses occur in the fall, winter and
early spring, when the surface evap-
Grafton of water is light, and the
drainage into water courses conse-
quently heavy. Under these condi-
tons the soluble plant food, made so
by the seasons tillage, is freely
washed into the drainage channels.
By keeping the soil covered with
catch crops. much of this loss may
be prevented, but it is not always
possible to use a cover crop. For this
purpose rye, scarlet clover, cow peas,
and field peas are used, and should be
used wherever possible. Fall plow-
ing is excellent in improving the
physical condition of soil, but the
plant food thus liberated is woefully
wasted by the spring rains. !
This wastage is condition which
we have to consider as practical
fact. One of the important matters
is the probable disturb
ance of the plant food balance by
such losses. Nitrogen we may disre-
gard, as, we can win that back by the
growth of legumes, clover, COW peas,
etc. Potash and phosphoric acid pre-
sent q different problem. Potash is
subject to severe losses. as when it |
is soluble in water, there are few
which render it again
insoluble. Phosphoric acid on the |
other hand is very apt to take in |
soluble forms, and the loss of this
plant food element is rather slight.
Every particle of lime encountered |
by the solution of phosphoric acid at
once fixes it against loss. All these
points must be considered in fgur
ing on any scheme to maintain the
fertility OF, the soil by applying man
ures or fertilizers.-V. J. Lance, in
Farmers Home Journal. 4es