The Springdale news., 1916-05-05
SOILS AND SOIL FERTILITY
No. 6. Rotation of Crops.
y L. w Osborn, Assistant Agronom-
list, College of Agriculture.

list, College of Agriculture.
In the improvement of present sys-
TENS of farming there is nothing upon
which success or failure depends to a
greater extent than the method of
cropping the land. Experiments which
have been carried upon the oldest ex-
pertinent stations have shown conclu-
sively that cropping practices bear a
very definite relation to the way the
soil fertility is maintained.
AS result of sixty years work at
the Rothamstead Station, England,
wheat in a good rotation gave nearly
double the yield per acre as was OBJ
tanned from the same crop when
grown continuously on the same land.
The yields under continuous culture
have fallen off most rapidly during
the first few years of the experiment
During the last fifty years the falling
off under continuous culture has been
comparatively little. and has now
reached a stage at which it may be
maintained regularly. The expert
ments in America, though conducted
for shorter periods, tend toward the
same results. At the Illinois station,
after ten years continuous culture,
corn yielded thirty five bushels per
acre Rotating corn with oats and
legumes gave yield of sixty.five
bushels of corn per acre.
These figures are of extreme impor-
lance when it is considered that cot
ton Is grown continuously on the same
land in Arkansas, and present low
yields. in large measure. can be at
tributed to this factor Experience
has shown that no nation, state or
community can maintain a prosper
ous agriculture without maintaining
soil fertility.
There are many reasons why
the yields of crop grown con-
tinuouslY upon the same land decline.
| In the first place, where certain
crop is grown continuously, the roots
appear 10 be adapted to the absorp-
ton OF certain limited forms of plant
food In few years the amount Of
| this plant food available becomes re-
duced and yields decline. Again,
under continuous cropping the fungus
diseases which trouble the crop are
! able to multiply until they become
serious factor in reducing yields.
/ Cotton wilt becomes a serious menace
under such conditions. Likewise va
rious experiments in the cotton belt
under boil weeyil conditions have
oh n nv %
weevil where cotton was not preceded
! by cotton.
| A good rotation is easily planned by
| studying the characteristics, feeding
! habits, and effects upon the soil of
/ different kinds of crops. A review Of
/ the staple field crops will show that
! these may be divided into general
/ groups for the purpose of studying
and planning systems of rotation.
/ /. Cultivated crops, such as cotton,
corn and sorghum. when planted to
allow for inter-tillage, have similar
| effects in rotation A cultivated
/ crop is beneficial because OF the
| cleaning effect it has upon most
weeds It is also an advantage in
aerating and pulverizing the soil, thus
aiding plant food to become available.
/ This advantage becomes disadyan-
tage when such crops are grown con-
! tinuousy on the same field.
2. Pasture and meadow crops. acll-
ed humus crops, are of considerable
Importance in maintaining the supply
of organic matter During the time
such crops occupy the land a turf of
roots and stems is developed which
fills the surface soil with vegetable
matter. When such a soil is broken,
the turf of roots and stems is mixed
with tn emineral part of the soil and
| gives IL a loamy, friabe nature not
secured with grain or cultivated crops
unless farm manure is added heavily.
8. Green manure crops are those
| grown for the purpose of producing
organic matter that can be plowed I'M
der. Such crops are beneficial in the
same way as the meadow crops.
When these crops are legumes, the
nitrogen supply is rapidly restored.
4. Cover crops are those grown for
the particular purpose of covering the
| land at those seasons of the year when
the soil is likely to be eroded and sol
uble plant food lost by teaching.
5. Small grain crops, such as oats,
wheat, barley and rye can be used to
good advantage in producing food
stuffs for the farm. Such crops seed
ed in the fall can serve the double
purpose of a winter cover crop and
hay, grain or green manure crop.
good rotation will consist Of the
judicious alienation of the above
groups of crops. The warm winters
and the humid conditions which pre-
vail in Arkansas require the growing
of winter cover crops and the turning
under of green manure crops. In a
general way, a good type of rotation
will be as follows; One or two years
of cultivated crops (cover crops plant
ed in the falD, the next year small