Decorah public opinion. (Decorah, Winneshiek County [Iowa]) 1895-1928, 1912-04-24
ROTATION NECESSARY
Peace and Prosperity of Iowa
Depends Upon Conservation
of Soil.
IOWA SOIL MUST BE SAVED.
Definite System of Crop Rotation
Live Stock Farming and Preven-
ton of Soil Erosion Advocated
by Expert.

Are you, Iowa farmer, public
curse?"
Are you soil robber?
If you are, stop. Swear off.
Future peace and prosperity for
Iowa depend upon the conservation
of her soil fertility.
Her rich, black acres are her most
valuable asset.
If you will regularly return to the
soil as much plant food as Is remov.
ed in crops grown and by blowing
and teaching, you can maintain their
productive capacity, not for gen.
Grafton only. but for all centuries to
come.
Iowa farmers, you do not general
ly practice this method of soil man
agement now. If YOU keep on in
this path, if some change is not eff
fected, the inevitable results will be
lower crop yields and a higher cost
of living.
Such is the message of Prof. W.
III. Stevenson, head of the agronOmy
department of the state agricultural
department, to the Iowa farmers.
| They ask him how they can reform
and save the golden wealth of the
soil. He tells them. His lesson fol-
| lows:
In the first place, our farmers
must, without exception, adopt and
persistently follow definite systems
OF crop rotation. A rotation in which
| legumes are grown makes it possible
to add to the soil, at a comparative
ly low cost, nitrogen and organic
matter.
In the case If most of the Soils sof
this state, which have been under
cultivation for a decade or q longer
period of time, these constituents are
now limiting factors in crop produc-
ton. That statement is not a guess
or an estimate; it is fact which
must be dealt with intelligently or
greatly impoverished soils will be
the rule and not the exception in this
state. How much organic matter
must be added TO the soil? A guam
tity sufficient to supply nitrogen for
the largest crops which can be grown
under our climatic conditions. We
should not be content with yields
which are cut short because of a lack
of any element of plant food. A so
bushel crop of corn requires as much
nitrogen as is contained in two tons
of clover hay or in eight tons of aver
age farm manure.
The most common, and undoubt-
edly the most satisfactory legume
grown in rotations in Iowa, is clover.
Now the roots and stubble of clover
contains no more nitrogen than the
clover plant takes from the average
SOIL Therefore when clover is grown.
for the purpose of increasing the.
nitrogen content of the soil, it is
evident that failure must result II
we return to the soil only the roots
and stubble.
The clover which is grown on the
| land must be plowed under as
green manure or the hay must be
| fed to live stock and the manure re-
turned to the soil. One ton of clover
hay contains forty pounds of nitro
gen. One bushel of oats (grain and
straw requires one pound of nitro
gen; one bushel of wheat (grain and
straw requires two pounds of nitro
gen; one ton of timothy hay requires
"a pounds of nitrogen, and other
crops require nitrogen in about the
same proportions.
! Organic matter contains all of the
nitrogen which is present in the soil;
therefore, the figures given. above
make it easy for any farmer to esti-
mate the approximate amount ln or
clover which he must plow under if
he depends upon this source of or
ganic material for the maintenance
of his supply of nitrogen.
One ton of average manure con-
tains ten pounds of nitrogen. In live
stock farming the total animal. ex-
crements contain, as an average,
three-fourths of the nitrogen from
the food consumed. We have here,
then, a basis for determining to just
what extent the nitrogen content of
the soil may be increased by the
application of manure. In this con-
nectiOn, however, 1t must be remem-
bered that the liquid excrement con-
tains more nitrogen than the solid
and 1t Is often difficult to save the
former. Again, manure rapidly loses
its valuable fertilizing constituents
from teaching and from fermenta-
tion and If left exposed to the sun
and rain for a period of six months
half it's value may be lost. One ton
Of clover plowed under adds to the
soil as much organic matter and as
much nitrogen as four tons of aver
age farm manure.
The organic matter of the sol
(and hence the nitrogen) must be
maintained by plowing under great
deal OF clover and all other products
except the grain, in the case of grain
farming, or by making use of al
produce, as feed for bedding, in live
stock farming, and returning the
manure to the land with as little loss
as possible.
The fertility of the soil may bt
most economically maintained by The
live stock farmer IL he has the abil
, ity to handle animals successfully
The chief reason Is that every type
of rotation we'll adapted to Iowa
VT ovaat rrantttfao ne nna 20.