Evening journal., 1918-07-31
Fertilizers for Wheat
BY A. 2. GRANTHAM.
Agronomist, Delaware College.

The lack of proper fertilization is
often the cause of poor yields of wheat
on Delaware soils. While the first con-
sideration is the thorough preparation
OF the soil through crop rotation and
good tillage, certain applications OF
plant food are necessary on most farms
to secure the best yields OF grain. The
use of legume crops and manure in the
rotation lessons the demandd for ferti-
lizers carrying a large per cent. Of
nitrogen.
The kind and amount of fertilizers
that may be used with the greatest
profit will depend on the previous crop
ping OF the land and its natural fer
tility. No rule can be laid down as
to what fertilizer formula is best for
wheat on all farms. However. there
are some general principles which ap-
ply TO the fertilizer requirement OF
wheat. On Delaware soils wheat re-
sponds readily TO a liberal use Of phos-
phoric acid. Experiments at this sta
| tlon show that phosphOric acid when
used alone. produces greater increase
i'm the yield Of wheat than either nitro
gen or potash used singly, indicating
that the soil is deficient in phosphoric
acid.
This does not mean that nitrogen and
potash are not necessary for the best
results. 10 is only when the three,
nitrogen, phOspheric acid and potash
are supplied in the proper amounts,
either by the soil or by the grower
that the maximum yield will be Sc
cured On poor soils IL will be neces-
sary to supply all three elements OF
plant food. Where the land has been
carefully rotated with legumes. or
where a legume such as cowpeas pre-
cedes the wheat crop only phosphoric
acid and potash are needed greatly. II
the soil has not been kept in a good
state Of fertility by rotation, the liberal
use Of nitrogen will pay. On farms
where fair to liberal amounts Of stable
manure are used on sod for corn, and
wheat Is 10 follow. phosphoric acid
alone is sufficient IL seeded early. Late
seeded wheat should always have more
nitrogen in order for it 10 make enough
growth in the fall to pass the winter
in good condition. II cowpeas are
turned under phospheric acid alone
will probably give the best returns.
Where IL is possible to plow land for
wheat early, or to follow some early
maturing crop, such as factory peas
or early potatoes, less nitrogen is
necessary in the fertilizer as the fallow-
ing Of a soil well supplied with organic
matter through several weeks tends TO
make available the soil nitrogen. 1t Is
well to apply 200 20 300 pounds Of acid
phosphate per acre under such condi-
tions. If manure is available FOR the
the wheat land spread it on the sur
face Of the ployed ground and disk
il in. This should be supplemented at
time OF seeding by 250 pounds Of acid
per acre. Wheat following |
tomatoes requires little fertilizer except |
200 to 300 pounds OF acid phosphate por |
acre. Tomato land should be seeded as |
early as possible after the tomatoes are |
II wheat follows wheat or |
oats. 300 to 400 pounds Of fertilizer /
from 2 to 4 per cent. nitrogen |
and 10 10 70 per cent. phosporic acid is |
II will not pay to use |
potash at present prices in the ferti- |
lizer unless conditions are such as to |
permit seeding at the proper time on
oil thoroughly well-drained and espe- /
cially adapted TO wheat growing. the |
effectiveness Of fertilizers is governed |
to a considerable. extent by the time OF I
seeding. Likewise, wheat may be seed |
ed much later II the proper kind and |
amount OF plant food is used. Where |
IL is planned TO tOp-dress the wheat |
with nitrate Of soda in the spring it is |
quite necessary that the crop be well /
fertilzed with phosphoric acid in the
fall.