The pioneer express. [volume] (Pembina, Dakota [N.D.]) 1883-1928, 1908-08-28

Ishown that natural rock phosphate
gives practically no immediate returns
II used in the absence Of decaying or.
ganic matter.
Humus is the decaying organic mat,
ter Of the soil. Its most important
constituent Is nitrogen. "A 100-bushel
crop of corn for 80 years would re-
quire as much nitrogen as is contained
in the first seven inches Of ordinary
corn belt prairie land; IL the stalks are
returned to the soil the nitrogen
would be SUFFICIENT for 48 such crops.
If we are to enrich the soil in nitrogen
by growing clover the clover must
be returned to the soil either by plow-
ing under directly or in the form Of
manure.
The animals retain one-fourth of the
nitrogen and phosphorus in the feed
consumed, and two-thirds of the or.
ganic matter in mixed feeds Not
more than one-fourth of the dry mat
ter and not more than one-half Of the
food elements will be returned to the
field in the manure, and If the manure
is left exposed to- the weather for
three to six months these proportions
should be divided by two.
The Ohio experiment station has
! as an average of Is crops of corn at
35 cents per bushel, 10 crops Of oats
at Is cents, IL crops of wheat at 20
cents. ten crops of clover and ten
crops of timothy at six dollars ton,
on land that is richer in phosphorus
than our land, but poorer in nitrogen
than our land, is found that every
dollar invested in phosphorus paid
back $4.76, while nitrogen or potas.
SUM paid for its cost.
The same station has found as the
average of sc tests in II years work,
that when rock phosphate was applied
in connection with manure, every dol
lar in rock phosphate paid back $5.6S.
On three different series Of plots at
the University of Illinois phosphorus
has doubled the yield of clover as an
average of the last three years.
On the Bloomington (Ill.) soil e1
pertinent field phosphorus increased
the yield of wheat ten bushels per
acre in 1905, increased the yield Of
clover more than one ton per acre in
1906, and increased the yield Of corn
following clover by 10 bushels per
acre in 1907. The increase in either
crop would practically pay the cost
of phosphorus applied for the three
years. In both the Illinois cases bone
meal, which is more expensive than
rock phosphate, was used.
Experiments with the rock phos.
phate were started more recently in
Illinois. but have given good results
on our soils. -Four years experiments
at the. university have resulted in an
average increase of the crop equal to
$7.95, while the $50 pounds of phos.
phorous applied cost eight dollars, but
210 pounds of it still remain in the
soil for use in future crops. The re-
suits of 1907 alone are an increase
of $11.68 or 1858 more than the cost
of the rock phosphate, while -four
fifths of the phosphorus applied still
remains in the soil.
The value of the increase from rock
phosphate in six crops grown in the
Galesburs experiment field amounts to
$14.40, or $2.40s more than the cost Of
the phosphorus applied, while four.
fifths of this phosphate still remains in
the soil.
Plenty Of nitrogen can be secured
from the air by growing legumes, the
organic matter of the crops can be
returned to the soil, but the ohe ele
ment phosphorus must be bought.
One ton of rock phosphate containing
$50 pounds of phosphorus can be
bought for about eight dollars; the
same quantity Of phosphorus in one
ton Of steamed bone meal costs SIS,
in two tons Of acid phosphate costs
$50, and in four tons of complete fer.
tilizer costs $50 to 500.