Gloucester County Democrat. (Woodbury, N.J.) 1878-1932, 1900-06-07

HuMus AND NITROGEN.

The Former Is Usually Measure OF
the other In the Soil.
Humus has been called ''the worlds
storehouse of nitrogen" This element
(nitrogen) is one of the essential forms
OF plant food and when bought in COM
mercial fertilizers is most costly. HUI
mus is the result Of the decay of vege-
table matter in the soil producing a
black or brownish black substance.
Some valuable facts in regard to hui
mus and to the mineral constituents Of
soil have been conc.sely stated by the
chemist of the Canadian experimental
farms rs follows: The nitrogen in hui
mus. which may be termed organic nj
trogen, is not directly available to crops,
but is rendered so by nitrifcation,
process resulting from the activity of
certain microscopic plants or microbes
within the soil which live upon and de-
compose the organic matter there pres
ent. Recent research has shown that
soil fertility is largely dependent upon
the presence of these microbes. Warmth.
moisture and air are primarily neces-
sary for the development and repro
duction of these micro organisms-in
other words, for the nitrification Of the
humus. Certain bases also, such as
lime and potash, must be present in
the SOIL so that as result of this proc
ess nitrates may be formed inorganic
compounds which crops absorb by
their rootlets for their supply of nitro
gen. Barnyard manure introduces into
the soil those microscopic organisms in
large quantities, a quality not possess
ed by chemical fertilizers.
Analysis has shown that the amounts
of humus and nitrogen are, generally
speaking, closely related and that the
former is a measure of the latter. A
soil poor in humus is likely to be def
cient in nitrogen. Fertile soils in tenn
perate zones are always characterized
by richness In humus and nitrogen.
The color of soil frequently indi-
Gates its quality in this respect, dark
brown and black soils possessing large
percentages of these constituents.
There are. however, exceptions to this,
as the presence of much red oxide of
iron, as in some sandy soils, may mask
the color of the humus.
The sources of humus in cultivated
soils are practically three-the decay
ing roots of crops, barnyard manure
and ''green crops" such as clover,
turned under. This last has of recent
years become recognized as an eco
nomical method for enrichment of the
soil in humus and nitrogen.
In addition to nitrogen, humus con-
tains certain small quantities OF inor-
ganic plant food, such as lime, potash
and phosphoric acid. These are liber-
ated by the decay of the humus in
forms most useful to plant nutrition.
The mechanical benefit to be derived
from humus is the betterment of the
soil. Drainage, blowing, narrowing,
cultivating and the like have for their
object the improvement Of the me-
chanical condition of the evil and, indi-
rectly, the liberation of soil plant food.
The presence of humus from the decay
of farm manure or other organic mat.
ter is a necessary factor toward the
same end. 1t is only necessary here
to emphasize the value of barnyard
manure, a material rich in heterogeneous
organic matter, in this connection. In
comparing farm manures with com
mercial fertilizers, this is point fire.
quently overlooked