The Portland daily press., 1892-02-26
ARTIFICIAL AND BARNYARD MANuREs.


Their Composition and alua'ioh as STATED
by a Scientific Agricuiturist.
The functions of manures, as briefly
stated by a professor of the University
Of North Wales, who has conducted
extensive manurial experiments, are:
/. In many cases the Improvement Of
the mechanical and physical conai-
ton and the texture of the soil to
which the manures are applied. Thus
lime, when applied to sour land decom-
poses, and therefore renders harmless,
the sour organic acids whose presence in
the soil is the.cause OF the sour OF acid
condition Of the land. When farmyard
manure is applied to land the texture
and physical condition OF the soil is
much improved by the organic matter
OF which this manure Is largely COM
posed. 2. In many cases manures act
on plant fo:d already present in the soil
and convert this plant food INTO such a
condition that it can be ABSORBED by the
roots of plants The manurlal value OF
lime is due principally to the action of
this manure on the food of plants al
ready present in the soil. 3. The most
important function of manures is to
supply plant food necessary for the
growth of crops which is deficient in the
soil. The necessary constituents of
plant food that are generally deficient
in soils are nitrogen, phosphoric acid
and potash.
Nitrogen occurs in manures as nj
trates, e. e.. nitrates of soda; ammonia
salts, e. g., sulphate of ammonia; or
ganic nitrogen, e. g., dried blood. Nj
trogen as nitrates is Immediately availa-
BILE as plant food. Nitrogen as ammonia
salts soon becomes available. Nitrogen
as organic nitrogen is much more slowly
available.
Phosphoric acid, combined with lime,
is generally present in manures as insol-
uble phosphate of lime, e. g., bone meal
and basic Stag; soluble phosphate of
lime, g. g., superphosphates. Insoluble
phosphate of lime is converted into solu-
BILE, or superphosphate, by treating it
with sulphuric acid. Soluble phosphates
are generally more active than insoluble
phosphates in promoting plant growth.
Potash is the valuable ingredient in
kainit and muriate of potash. Potash
has generally better effect on light
than on heavy soils. Superphosphate
and nitrate of soda should not be mixed,
OF if mixed must be sown Immediately.
This also applies to the mixing of basic
Stag and sulphate of ammonia.
Artificial manures should be pur-
chased on a guaranteed analysis, and
the source from which the fertilizing in
gradients of the manure are derived
should be stated. This precaution is es-
pecially necessary in purchasing bone
or mixed manures. The percentage of
nitrogen in mannre should be stated
in its equivalent of ammonia, that of in
soluble phosphoric acid as phosphate Of
lime, soluble phosphoric acid as phos-
phate of lime, and that of potash salts
in their equivalent of potash. Artificial
manures are valued according to the
quantities of nitrogen, soluble phosphate
of lime, insoluble phosphate of lime and
potash they contain.
Farmyard manure contains all the in
gradients of plant food. This manure is
exceedingly variable in quality, as the
quality varies with the nature Of the
food given to the animal, the nature and
amount Of the litter used, the method
by which the manure is produced and
its treatment from the time of produc-
ton until it is applied to the land.