The Grenada gazette. (Grenada, Miss.) 1885-18??, 1886-03-13
SOIL
Directions for h Renovation Of Worm
Out Lands.

The object of the practical farmer is
to raise from a given area Of land the
largest quantity of the most profitable
produce at the least cost, and not only
avoid impoverishment of the soil, but
to FENDER it gradually more productive.
If we give abundant and invigor-
ating food to an animal it becomes
vigorous and fat; on scanty and slight
ly nutritive food it continues poor and
lean.
1t is precisely the same with plants.
If they find all the substances which
they require for their nourishment and
full development in abundant quantity
and in suitable form in the soil and in
the air, they will grow up more vigor-
ously and put forth more branches,
leaves, flowers and fruit than when
they meet with these substances, or
even one of them, in insufficient guam.
tity. By rich and plentiful food the
farmer fattens his cattle; by rich and
plentiful food he can also fatten his
plants.
1t is found in practice on our COM
non agricultural soils that there is
usually wanting only three of the con-
stituents which arc found in an agri-
cultural plant. The others are called
for in so small quantities, or are in the
soil in such large quantities, that sue
cessive Groupings for many years could
not exhaust them from the soil.
Only three of the constituents Of
which the soil is composed become ex-
hausted in practice, namely, nitrogen,
PHOSPHORUS and potash.
Furthermore, in all calculations re-
garding the exhaustion of the soil it
must be remembered that there are
certain natural processes continually
going on which affect the results.
In the first place, the available plant
food of nearly all soils is being slowly
dissolved out and carried down beyond
the reach Of plants by the natural or
artificial drainage of the soil.
This is particularly true of nitrogen,
lime and s~ulphuric acid. On the other
hand, rain and snow are constantly
dissolving nitrogen compounds out Of
the air and adding them to the soil,
while the "weathering' Of the soil,
which is constantly going on under the
influence of heat and cold, frost, water
and carbonic acid, is constantly con.
verting rock dust and organic matter
into available plant food. The rapidity
of these latter processes is roughly
measured by the amount the soil will
produce for a number of years without
manuring, and, since practically all
soils will produce something under
such conditions, it follows that, if we
return to the soil as much fertilizing
matter as we took from it, we are toll
erably certain that w are not impov-
crishing it, while in most cases it will
grow richer under such treatment.
This is certainly true of the mineral
matter of the soil, and the invcstiga-
tons Of Lawcs and Gilbert have shown
that in R%othanstad the annual loss of
nitrogen by teaching is just about coy-
cred by the amount annually brought
down from the clouds. If this is APP
p~roximately true for other localities, as
is most likely the case, then the con-
clusions drawn above for the mineral
matters apply to nitrogen as well. Of
the final test of the accuracy Of
such calculations is the actual crop
producing power Of the soil, as deter
mined by experience; but the calcula-
tons possess the double merit of en-
us to predict, to a certain ex-
tent, the effect of a proposed future
curse of cropping upon the fertility of
a farm, and of showing us, in case of
fertility, not only the cause of
the deficiency, but also what particular
element or elements are probably de-
icient and need to be supplied in
manuring.
The quantity of nitrogen, phosphoric
acid and potash taken from the soil by
he following crops is as follows for the
quantities named: