Oxford Democrat. [volume] (Paris, Me.) 1833-1933, 1913-04-22
humus In the Soil.
FUNCTION, MAINTENANCE, UTILIZATION.


out in the lecture given by Professo
Simmons in the Farmers Week Cours
at the University of Maine on Humus il
the Soil. The following is an abstrac
of this very practical lecture:-
Humus is organic matter in the soil II
an advanced stage of decay. Its darl
color causes the darker color Of the soil
Peat is an accumulation of organic
matter whose decomposition has beer
checked in a very early stage. Usual!
it is comprised of some form of moss.
Muck represents more advanced
stage of plant decay than peat, and usu
ally contains quite quantity of humus
The composition Of humus is quitt
variable. In some of its many carbon
compounds II contains nitrogen and alst
all Of the mineral elements necessary Il
plant and animal life. The elements are
in their simplest and most available
form. The average percent OF humus il
237 types of soils in the United States
shows an average content OF 06 percen,
| of humus and the sub-soil .SS percent.
Clay soils contain more bumus than
sandy soils, because it is less readily
leached from the clay soil.
Organic matter in the soil in the form
of humus affects the soil as follows:
/. The PARTICLES of organic matter act
as little sponges, and hold water in avail.
able form for plant growth even against
periods of drought.
2. The mechanical condition of the
soil is improved; in clay by the grouping
of fine soil particles into groups, or clus-
ters, allowing greater sized sir spaces; in
sandy soil it acts as a binding material,
thus preventing loss of plant food by
teaching.
8. In its process of decomposition it
generates acids that assist in making
available the mineral plant food.
4. By darkening the color of the soil
1t enables il to absorb more Of the SUMS
rays, causing it to become better adapt
ed to early crop growth.
8. 1t supplies material to support soil
organisms that are so essential in the
preparation of plant food.
To utilize the humus OF the soil 1t is
well to keep crops growing in the soil at
all times, when the conditions for the
active development and use of the humus
material is the best. Is percent F, and
the above cause very rapid action of soil
organisms, particularly If the moisture
content is favorable. A moderate
amount Of moisture and some air pro-
duce the best condition for organisms to
do their best work.
The supply of micro-organisms may
be insufficient. Often, when turning
under heavy green manure crop, II
would be an advantage to supply small
quantity of partially fermented manure,
in order to increase the supply OF the de-
sirable bacteria. Lime, in this case, is
valuable, in that IL counteracts the free
acids in the soil, which are harmful to
the bacteria that are needed. Cultiva-
ton of the soil causes rapid decomposi-
ton, which allows the utilization of
plant food by the plant to Its greatest
capacity.
To maintain the supply of humus in
the soil, organic matter, vegetable or
animal matter must be supplied faster
than il is used. Chemical fertilizers can
not make up for lack of humus, while
their effectiveness may be increased on
account of an abundance of humus. The
ordinary means Of accomplishing this is
to supply it in the following forms: /.
Application of muck; 2. Manure from
animals in pastures; 3. Organic matter
in commercial fertilizers; 4. Stubble,
roots, etc. turned under by plowing; 8.
Stable manures; Green manures.
Muck or peat, when close at hand,
may be prOfitsbly employed to increase
the supply of humus. 1t should be
allowed to drain, so as to free 1t from the
water that it contains. They contain nj
trogen, but it is slowly available. Ma
nure dropped in the pasture gives far
less return than If spread from the barn
and incorporated into the soil. The Or
ganic matter in commercial fertilizers
is not usually in sufficient abundance
to be of any great help as supply of
humic material. Stubble and roots
serve a good purpose, and If from legu-
minous plants increase the supply of nj
trogen. Stable manures add greatly to
the supply of humus, besides introduc-
ing desirable bacteria to work upon the
organic matter turned under. The humic
value of stable manure accounts to quite
an extent for its high value in the soil.
Cornell University Station IN New
York secured the following results from
experiments on hay: Twenty tons of
manure per acre gave yield of 1920 lbs,
of hay per acre, while 10 tons gave 1850
lbs, and no manure gave 2230 lbs., show
ing an increase over no manure Of 232
percent for the 20 tons per acre, and
nearly 100 percent for the 10 tons per
acre. Valuing the hay at SIS 90 per ton,
it would mean that the first years in
creased crop would give an increased
money value Of s3l.92 and Sl6.72 re-
spectively, leaving improved physical
conditions to affect future crops. Out
of the S5l.60 chemical value usually at
tributed to 20 tons OF manure SSl.92 re-
turn was secured for the first year, leav-
ing less than $1,000 to be secured from
later crops.
This first year yield might be attrib'
uted to the plant food supplied in the
manure. This experiment should, how
ever, be studied in connection with the
following one at the Rothamstead Ex-
pertinent Station. Land growing barley
aud wheat continuously for forty years
was treated as follows: One-half bad no
manure; the other half manured every
year for 20 years, and then not manured
for the next twenty years. The first
five year period after the first 20 years,
the land gave an average increase yield
of 20 bushels per acre, the unmanured
land giving IS bushels per acre. The
second five year period gave an increase
weld of Is bushels, the third five years,
l6 bushels, and the fourth years, II
bushels per acre, making in all for the 70
years total OF $40 bushels of gain on
one acre after the application of manure
had ceased.
With the Rothamstead experiment the
later effects were due largely to the i'm
proved physical effect, as the original
plant food in the soil had disappeared In
increased yield as the manure decom
posed.
One Of the best methods of increasing
the humus in the soil is by the use o
green manures. Two classes of plant!
are used for green manuring. Buck
wheat, rye and rape are crops that may
be used for this purpose. These secure
the soluble plant food, and store 1t in th'
soil, and besides, keep up the supply o
organic matter. Buckwheat occupies
the land during the growing seasons o
our ordinary field plants, but 1t gives I
good supply OF material to turn under
Rye may be sown in the fall, and turnet
under in the spring. Rape Is used as
fall catch-crop.
The legumes, such as clover, fell
beans and field peas, arc preferred, be
cause of their nitrogen gath 'ring habits
The second crop Of small red clover 1
the crop most often used.