The Milan exchange. (Milan, Gibson County, Tenn.) 1874-1978, 1886-08-28
COMPOSITION oE SOILS.
A Study Which Every Intelligent Land
Owner Should Pursue.

a Study Which Every Intelligent Land
Owner Should Pursue.
There is no more important study for
the farmer than a careful study of his
soil. While soils are composed OF three
distinct constituents-sand, clay and
humus-yet these vary greatly in their
composition. All soils, as far as their
inorganic materials are concerned, were
originally composed by the breaking
down and decomposition of rock.
Sands result from the decomposition of
quartz, or other rock containing quartz
or silica in some form, and the compost
ton of each individual grain is that of
the rock from which it was formed.
Soils formed of granite are among the
most productive known. WhyP Gran
tie is composed of quartz, feldspar and
mica. The quartz is pure slick, so
necessary for the proper division of
Soils Feldspar again consists Of silica,
alumina and potash. Alumina is the
base of clay, just as the metaLilluminum
is the base of alumina, alumina being
an oxide of aluminium, and is the char
acteristic ingredient in all clays. With
out il soils could not be combined and
held together. With too much alumina
it becomes too dense, hard and impervi-
Gus both to water and the roots of
plants.
Humus is any organic matter in pro-
cess of decay or in that state wher re-
duced to an impalpable powder. Prai-
RE soils contain great deal OF humus
that seems to have been deposited when
the soil was under water or partially so.
So the fact that these soils, as a rule,
are largely composed of clay are due
their fertility and lasting qualities, the
dark color of the soil being due to
humus, and also to the effects of burn
ing of the vegetation year after year.
Soils are generally classed as sandy,
loamy, clayey, mucky and peaty, the
latter being formed in marshy land UNI
der water Our very black prairie soils
containing much clay and vegetable
matter, are often designated muck. A
distinctly clay soil is that composed Of
pure clay. Pure sand has no fertility,
pure clay can not be classed as fertile
and peaty soils are not fertile until they
have long been unearthed by careful
thorough drainage.
Mixtures of sand and clay are oul
most fertile soils. They are classified
as loan when they contain equal vol.
nmes of sand and clay, as sandy loan
when about seventy-fiye per cent il
sand, and as clay loan when abou
seventy-tive per cent is clay As soil
approach either of these conditions they
are classed with that to which they re
late most closely.
The province of humus in the soil i
two-fold; to render the soil light ant
mellow, though its principal value il
the power that humus possesses of de
composing and rendering soluble tn
valuable constituents of the soil, es
pecially those of potash with nitrogen
Humus is formed by the action of tn
air on solid animal or vegetable matter
In fact, it is a process of exceedingly
slow combustion, as much as five hun
bred years being considered necessar
to reduce q large oak to humus in tn
udIllI Ill DlORlCoo VI hbNtlNs Dul my 81
this time, however, such portions a
are gradually converted into humus ar
performing their natural functions j
the soil. One of the most important
the conservation of nitrogen-the mo,
costly, as it is the most easily dispelle
of the organic products. Under tn
action of heat and moisture troge
combines with the potash of the sol
forming nitrate of potassa, the commo
name OF which is saltpeter.
From the foregoing the farmer ma
by careful observation estimate tn
value and character of his soil, an
hence the proper crops to be used, an
also the manures necessary to increaS
productiveness. A sandy soil may |
rendered productive by the addition
clay. Ten per cent of clay will col
vert it into sandy loan. But a pul
clay can not be rendered productive /
the addition of sand. 1t would requil
at least twenty-five per cent of sand
convert it into a stiff clay loan. Pun
clay freed from uncomJined silica co.
sists of alumina 40, silica 40 al
water 1873 parts in 100. But except
rare cases it is not found, except con
oined more or less, with free silica,
Jand.-C Chicago Tribune.