The Harrison times., 1917-06-02
WHATS WHAT IN
GOOD FERTILIZER.
Information About Commercial Fertl-
lizers Which Is Worth Keeping
For Reference.
BY De F. Hungerford, College Of Agri-
culture. Fayetteville.

BY De F. Hungerford, College OF Agri-
culture. Fayetteville.
Fertilizers are materials that sup
ply one or more OF the three most
important plant food elements-nitrO-
gen, PHOSPHORUS and potassium.
Nitrogen Fertilizers.
The common nitrogen fertilizers
are nitrate OF soda, sulphate OF am
monia, cotton seed meal dried blood,
tankage and cyanamid.
Nitrate Of Soda contains from 10 ID
16. per cent OF nitrogen. 1t is soluble
in water and therefore Immediately
available to the plants. The amounts
applied vary from 100 to 400 pounds
per acre. Because OF its solubility II
should be applied either at seeding
time or as a top dressing after the
crop has come up. II used as top
dressing 1t should be put on while
the plants are dry for otherwise the
leaves may be burned. Recent tests
have shown thatnitrate OF soda Is very
beneficial to apple trees when applied
at the rate OF five or six pounds per
tree when the flower buds begin 10
show pin color,
SuIphate Of Ammonia is byprod-
uct in the manufacture OF coke and
coal gas. 1t contains about 20 per
cent Of nitrogen, which is nearly rs
readily available as that in nitrate OF
soda. It is used at about the same
rate per acre and In much the same
manner as nitrate OF soda. Sulphate
Of ammonia should not be used on
acid or sour land unless lime is ap-
piled with it to overcome the acidity.
Cotton Seed Meal has been used
very extensively in the South as
fertilizer, but it is coming into such
general use as a stock food that only
the inferior grades can now be used
proftably. The nitrogen content
ranges from to 7 per cent, and it
contains in addition 2.5 per cent OF
phosphoric acid and IL per cent OF
potash The nitrogen is not soluble
and must decay in the soil before It
can be utilized by plants. For this
reason application should be made
one or two weeks before the crop Is
planted.
Dried Blood and Tankase are not
soluble in the soil water and, like co.,
ton seed meal, must be applied
week or more before planting time.
Neither is used as extensively now as
formerly. Dried blood contains from
10 to l13 per cent Of nitrogen
Tankage is more variable ft5
nitrogen content ranges from to IL
per cent and phosphoric acid from 7
to 20 per cent.
Phosphorus Fertilizers.
The important PHOSPHORUS fertilz-
ers are acid phosphate, raw and
steamed bone meal, basic Stag, bone
tankage and raw rock phosphate.
Acid Phosphate is ground phosphate
rock treated with sulphuric acid
There are three grades containing re-
spectively II, IA and Is per cent phos-
phoric acid. Although the phosphorus
in acid phosphate is readily available
and can be taken up by the plant as
10 inI ia Ianp ph.I
out, because the soil absorbs and
holds phosphorus until the plants
need it, The rate Of application is
from 200 to 400 pounds per acre. Acid
phosphate gives the best results on
heavy clay land and on soil that Is
not acid.
Ground Bone in the natural con-
dition contains about per cent OF
nitrogen and about 22 per cent
OF phosphoric acid but the ma
terial ordinarily sold as a fertilizer
has been steamed to remove the fat
and glue which takes out most Of the
nitrogen. The result Is ma.
terial with from "a to 27 per
cent Of phosphoric acid and 1-2 to
2 per cent of nitrogen. Bone phos-
pilates are not so available as acid
phosphate and give best results on
meadows and pastures.
Basic Stag Phosphate is a by-prod-
uct from the manufacture OF steel. It
contains from Is to 10 per cent OF
phosphoric acid and from 35 to so per
cent of lime, The phosphorus ia
more available than in bones, but less
available than in acid phosphate The
lime content makes It good ferti-
lizer to use on acid soils.
Raw Rock Phosphate is the un.
treated, finely ground phosphate rock
II contains from 28 to 32 per cent OF
! phosphoric acid To be at all effective
the raw rock phosphate must be
ground to very fine powder. At
least 95 per cent should pass through
screen with 10000 openings to the
square inch. It should be applied at
the rate Of 1000 pounds per acre once
in four or five years 1t should be
thoroughly mixed with the soil by
narrowing several times.
Rock Phosphate Is only slowly
available. It should not be used
when immediate returns are needed
such as on truck crops or on rented