Republican news item. [volume] (Laport, Pa.) 1896-19??, 1901-11-14
Organic Matter in Soils.

according to Mr.. F'reer-ThOnger OF
England, who has devoted much of his
time to the investigation of soils, all
vegetable matter which grows and dies
on the soil is transformed into humus.
Formerly it was supposed that humus
alone furnished food for plants, hence
the fertility of soil was estimated ac.
cording to it's content in humus or or
ganic matter. There was some truth
in the belief for in organic matter un-
dergong decomposition there exists nj
trogenous matters which are gradually
converted into ammonia and nitric
acid Carbonic acid gas is also a prod
uct of decomposition, which acts pow
erfully in rendering soluble the min
eral elements of the soil. Humus soils
have the property of retaining the SOL
uhle mineral salts, which are so easily
washed away into the subsoil. Soils
containing much humus are easily
worked, and owing to their dark color
are easily warmed by the sun. Such
soils give good returns when dressed
with phosphate, although on clay soils
less potash may be required than on
light sandy land. The application OF
lime favors nitrification of the nitro
aenous organic matter. 1t is claimed
that humus soils are rich in nitrogen,
poor in phosphoric acid, with varia-
BILE quantities of potash. Sandy soils
are poor in all the plant foods. Clay
soils are rich in potash, poor in phos-
phoric acid, but vary in nitrogen.
These claims, however, depend largely
upon the characteristics of soils, their
treatment and the kinds of crops that
have been grown thereon.
Humus is formed under many con-
ditions. Leaves, roots, straw, manure
and green substances that have been
turned under all assist in the work.
The value of humus does not depend
exclusively upon its content of plant
food. but mostly in the influence it ex-
erts on the soil in relation to it's ply
sical condition, and its acid in render
ing the plant food Of the soil availa-
BILE for the sustenance and growth of
plants. The upper portion of the soil
usually contains more humus than the
deeper portion which marks or con-
stltutes the difference between soil and
subsoil. Humus is the great reser-
voir which retains the soil moisture
and nitrogen. 1t absorbs moisture like
a sponge and prevents escape of mois-
ture that would otherwise be lost; but.
while it stores up nitrogen and other
plant food it slowly and constantly
gives out carbonic acid gas as a result
OF decay of vegetable matter. This
acid acts on stones, soils and all in
soluble materials, setting free the pot
ash and phosphates contained, thus
providing plant foods for crops. Be-
sides carbonic acid evolved from hui
mus, other vegetable acids are formed,
which combine with lime, potash and
other substances to form humates. All
of these processes are constantly oc-
curing, the plant foods of the soil be-
coming available even when the farmer
does not assist in the work, for it is
well known that one of the most di-
rect and effective methods of adding
to the humus of the soil is by the plow-
ing under of green crops, which collect
carbon from the atmosphere, and il
clover, peas, beans or other leguminous
crops are used large amount of nitro
gen is also added to the soil. The use
o. green crops is almost necessary in
order to promote the formation of hui
mus, although it has been demonstrate
ed that when the ground is covered
with sod or any other covering there is
formation of humus under proper
conditions.
Every farmer should endeavor to so
rotate and cultivate his crops as to
promote the formation of humus, but
It may be stated that it has been found
by experiment when the soil was we'll
supplied with the phosphates and pot
ash there is more humus formed than
when such mineral substances are de-
ficient, hence no farmer should depend
upon green manurial crops exclusively.
Even barnyard manure, which pro-
notes the formation of humus, will not
give as good results as when both ma
nure and fertilizers are used 1t is
the duty of the farmer to keep his land
we'll supplied with all the essential
elements SC necessary for plants, for it
is often grave mistake to allow any
substance to be lacking, as there is
such thing as a superabundance of
one substance with an insufficiency of
others, in which case the crop will
make excellent progress for awhile and
then fail to utilize more of the partic-
ular plant food with which it has been
overfed. Humus assists in providing
all the fods, and also holds the mois-
ture for the supply of the crop. There
is constantly occurring in tho soil more
or less loss of plant food. Exposure at
certain seasons is injurious to soils.
Shade Is one of the conditions re-
CURED by soil bacteria, and shade con-
duces to the formation Of humus. In
fact, all farmers know that when
heavy sod is turned under the result is
large addition of humus to the soil.
Such sod land may have been closely
cropped by grazing cattle, but it gained
in fertility. due to the shading of the