The morning news. [volume] (Savannah, Ga.) 1887-1900, 1893-05-15
HUMUS.

iect and Worthy of Deep Consider
alton.
Humus, or vegetable mold, is simply
vegetable matter that has become decom-
posed in the soil. All vegetable matter
contains a small percentage of mineral or
inorganic matter known as ash, a small
percentage also of nitrogen; and, however
drv it may become through the influence
of air and sun, contains certain proper
ton of water.
The ash and water being deducted. the
remainder is denominated organic mat
terof vegetation. For instance, 100 pounds
of wheat straw that has been exposed to
the sun and air until it was become per-
fectly cured as hay still contains fourteen
pounds of water. (Hygroscopic water
that is termed)
This fourteen pounds of water can only
be extracted from the straw by exposing
it to a temperature of 212o-a de-
gree of heat far above what the sun can
give in this climate. Deducting this
fourteen pounds of water from
100 pounds of straw leaves eighty
six pounds of perfectly dry straw;
and if this eighty-six pounds of
straw is burned it win be
converted into 81 pounds of
ashes, the visible remainder, the
other S019 pounds having gone into the
atmosphere as SO much smoke.
This S0% pounds is the organic matter
Of the 100 pounds of straw, which, when
decOmpOsed in the soil, constitutes humus.
This organic part is composed of the
four atmospheric clements carbon, nitro
gen, hydrogen and oxygen.
Now, if this S0l5 pounds of organic or
vegetable matter is decomposed through
heat, but protected from the air, it would
assume the form of charcoal-losing about
so per cent of its weight.
We see that humus and charcoal are
the same substance in a little different
form. This charcoal, again exposed to
heat in the forge of the blacksmith, with
q current Of oxygen from the bellows, is
again decomposed and forced into the
atmosphere, with its small proportions of
mineral matter left as ashes on the
hearth. As humus or charcoal the solid
and tangible part of vegetable matter is
carbon. Now, just as nitrogen is available
only as il becomes converted into am
monia, so also carbon is of little avail
until it has become converted into car
bonic acid, so far as plant food is con-
cerned. We know very well that neither
humus nor charcoal is taken up by the
roots Of plants in their immature state,
but is useful and essential in the soil as a
store house for Carbonic acid.
Humus or vegetable mold in the soil
LGhuSLo uil6 sOlI more porous, prevents IL
from baking or crushing and enables the
air TO STIR more freely than it would in
soil composed only of earthly or mineral
matter
Humus is also a great absorbent of
moisture, catching it up and holding it
after rain much longer and in much
greater Quantities than ordinary earthly
matter can; and again, as the soil dries
on, 1t has greater capacity for
Of 10
Subsou below it, aiding capil
larry attraction. Humus is also credited
with straining out from water any am
monlacal matter that may have become
dissolved in the water, and thus prevent
ing its escape into the subsoil, where it
would be out of the reach of the lateral
roots of plants.
Humus from some forms of vegetable
matter is much richer in certain clements
than that from other forms. Wheat and
pine straw, for instance, are very much
inferior to the vines of clover, yetch pea
and other leguminous plants.
These latter are five to seven times
flcher In nitrogen than the straw of any
OF the small grain, and all this nitrogen
Is secured to the soil when the matter is
turned under at the proper stage. Our
common rag weed is also superior to the
straw OF small grain in this respect This
Is the reason why the leguminous plants
are esteemed as the most suitable for
providing vegetable matter.
whenever vegetable matter is covered
up by the soil whatever nitrogen is in it
by decomposition is yielded up and alb
sofoed by The soil. Carbonic acid and
ammonia are the two requisites for
iu%urlant growth of stalk or weed and
both must be obtained chiefly through the
SOIL, and to a great extent through the
influence of humus.
soils that are persistently devoted to
hoed crops in our climate, with its long
summers and scorching sun, are more
rapidly exhausted of their humus, than
Ihe soils of the north where the summers
are shorter and where a more rational
system OF culture is practiced.
A great loss of humuS follows the
turning up of soil and exposing it afresh
70 the scorching rays of the sun from
June to September, and wise system of
!drmlng Will guard against turning up, IN
yhe summer any more than can possibly
be avoided
IL can be justified only when the object
Is to plant quick-growing crop that will
soon shade the land and ultimately be
given to the land
=, Our field pea is about the only plant
mat is adapted TO this purpose for sum-
mer planting. With good cultivation a
crop of peas can be made over when
planted in July. But how many of the
plants have we that we can successfully.
plant in midsummer Very few farmers
as vet have found that the pea has any
great value as a money crop, as it is an
expensive crop to market. And it is
valued chiefly as a manurial or fallow
crop, holding the position here that clover
does in the north. AS fallow crops it is
NOT probable that we will ever find two
pants more suitable for general use than
The clover and the pea.
While other plants may be resorted to
cordially for the purpose of supplying
humus to the soil, these two will be the
common reliance for that purpose for long
time to come.
IL may be said that we have notentered
on their use yet for this purpose, eOmpar-
ing the present use with what we will
make Of them In the future, when we
come to farm more scientifically than we
90 now We nan nnlu annlM NeaoLalLo