The county record. [volume] (Kingstree, S.C.) 1885-1975, 1902-03-13
SOIL FERTILITY.

OWL y CR I'LL -
Interesting Conclusions From E1-
perimeHts with Fertilisers.
Valuable and thorough experiments
In the maintenance of the fertility OF
the soil have baen continued for O mum.
be, of years at the Ohio station, The re.
suits of these experiments appear to
Justify the opinion that for the crops
and soils under test phosphoric acid is
at present the most important constitu.
ent Of q fertilizer. with nitrogen and
potash following In the order named.
Further conclusions drawn by the sta.
ton are:
The largest increase Is only obtainea
when the fertilizer contains all three OF
these constituents. but it does not az
yet seem necessary to use nitrogen and
potash in 90 large proportion, relatively
to phosphoric acid, as would be indicat-
cd by the chemical competition Of the
crops.
Apparently, phosphoric acid should
considerably exceed either nitrogen or
potash In quantity in fertilizer for
corn, oats or potatoes, while for wheat
the proportion Of nitrogen may closely
approximate that Of phosphoric acid.
Nitrate Of soda is apparently the most
effective carrier of nitrogen in common
use as fertilizer, but it can seldom be
used with economy in Ohio because Of
the relatively high cost Of its nitrogen.
Slaughterhouse tankage, which is the
carrier of "ammonia" in practically
all the factory mixed fertilizers sold in
this state, is probably less effective
carrier of nitrogen than nitrate Of soda,
but the cost of nitrogen in unmixed
tankage, when due allowance is male
for the phosphoric acid carried by the
tankage. is so much less than in nitrate
Of soda that tankage becomes q much
more economical source of nitrogen to
the Ohio farmer than nitrate Of soda.
This advantage in tankage disappears,
however, when it is purchased in tho
ordinary factory mixed fertilizer. since
the price at which such fertilizers are
generally sold brings the cost Of their
nitrogen to a higher figure than its
necessary cost in nitrate Of soda. while
the experiments reported in bulletin 9S
Of this station indicate that the nitrogen
If the factory mixed fertilizer is not
more effective than that Of ordinary
tankage.
Dissolved boneblack is apparently .
more effective carrier Of phosphoric acid
than rev bonemeal or acid phosphate,
but dissolved boneblack, like nitrate
of soda, is seldom or never used in the
compounding Of factory mixed fertil.
isers in Ohio, because Of the lower sosS
of phosphoric acid in other materials.
Acid phosphate, on account of its
comparative cheapness and large sup
ply, has become the standard carrier OF
fertilizer phosphoric acid. Our expert
ments indicate that commercial acid
phosphate, like slaughterhouse tankage,
is variable in composition, and both
materials should only be bought on
guaranteed analysis.
Our experiments fully support the i'll.
ference that the phosphoric acid OF bone-
meal and tankage, when these materi-
ais are finely ground, is quite as effect
i've. pound for pound, as the available"
phosphoric acid of acid phosphate. and
that these materials, unlike boneblack
and Carolina rock. require no treatment
with sulphuric ucid to make their phos.
phoric acid available, provided only the
grinding be done with sufficient thor
oughness. Investigations indicate that
there has been decided improvement
in grinding within recent years.
Basic slag appears to stand next to
dissolved tcneblack in effectiveness as
q carrier Of phosphoric acid. Apparent
ly this result is in part at least due to
the superior mechanical condition Of the
Stag meal, as it is an extremely fine pow.
der. This material is not treated with
acid.
These experiments show that the fer
tiiizing constituents Of barnyard ma
nufe act more slowly than those Of COM
mercial fertilizers, but as they cost
much less In manure Ii becomes the
cheapest fertilizer.
The advantage Of Supplying manure to
the surface instead Of plowing 1t under
is strikingly shown.