New Ulm review., 1913-01-22
Use Manures in aa
Crop Rotations.
~ PROFESSOR ANDREW
BOSS; AsrieuIturist, Unissr-
slty Farm, 81. Paul.
pAote Ainn. Agricultural College.

olty Farm, 9t. Paul. :.
.+++++++++++s+!-.s. = J. i. I.
II. The. rotation of crops has been
Eongly advocated during recent
gsars. Because crop yields have been
snoreassd in some cases by rotation
1aany are led TO believe that some
1ling q added to the fertility Of the
toil Ay crop rotation alone. Nothing
Noald 10. farther from the truth. In
Aet Il 10 likely that the aggregate
Amount Of plant food is more quickly
|kAasstsd b. rotating the crops than
~ 0ingis cropping, provided no ma
1lEes o.. fertilizers are used In either
>ass.
III Thst yields are temporarily stimu-
I Aatpd BY rotation is we'll shown in the
.1ssuNs from the crop rotation plots
~ University Farm. Wheat grown
ssatinuously has yielded 1873 bushels
-. acre for = ten-year period. In the
AAnee-year rotation for the same pc
1i1d u has yielded 70.6 bushels. Corn
.SAae yielded IT'S bushels an acre
11ere grown continuously and 46.3
tAushels where grown in = three.year
rotation Of wheat, clover, and corn.
The yield of hay on continuous mead
sOW 10 IL tons and in the three-year
nutation 2.7 tons an acre. The yields
ere larger with each class OF crops In
.rotation The very fact that the
yields are larger suggests that more
Plant food is taken from the soil in
producing them. No plant food is
added by the growing crops except
that nitrogen may be gathered from
the air in the soil spaces by the bac-
terra on the roots of the clover plants.
Ian other elements of fertility are
more rapidly exhausted by the larger
crops grown on the three-year rota.
stion fields. Doubtless the bacterio-
1ogical and physical condition of the
ssoil Is improved by the change of
sGops in rotation. thus accounting for
at least . part Of the increased yield,
hut It IL probable that unless manures
and fertilizers are supplied the yields
N the three-year rotation without
Manuring the land in the following
years will decrease. Poor soil condi
lions and correspondingly poor plant
growth 10 even now noticed in the
clover and corn crops.
In q five-year rotation where eight
items per acre of barnyard manure are
applied once in Ave years, wheat has
averaged 27.4 bushels per acre during
Tie ten-year period mentioned above.
corn 61.3 bushels and hay 3.6 tons an
acre. f-r ,s. a ~ -s##
II will be noticed that the yields
are materially increased by the use
.of m1uures. The aim In q, we'll bal.
anood rotation should be to return In
Ahs manure the elements removed by
&he growing crops. For every pound
u nitrogen, phosphorous. potash or
etler material taken from the, soil
fsr crop growth pound must be re-
turned II the normal supply is to be
maintained. .a.F -...-
Most of our farm crops will take
from the soil yearly from twenty-five
to 100 pounds of nitrogen, about twen-
ty-five pounds of phosphoric acid and
thirty-five to sixty pounds of potash.
Any rotation scheme to be correct
must provide for replacing these ma
tsrials. Barnyard manures offer the
hest agency for this supply 1t may
he that in years to come 1T will be
necessary to add mineral fertilizers
sact as phosphorous, potash, lime, etc. |
AS rotations for the maintenance or !
production the following are suggested: !
Three-Year Rotation.
First year: Grain-sown to red
e4over eight pounds per acre.
Second year: Glover hay, two
in fall-top dressed IN
faH or winter with six tons per acre
a barnyard manure evenly applied.
Third year: Corn.
Five.Year Rotation.
Z First year: Grain, seeded to tim
SHY eight pounds and clover six
sounds.
= Second year: Timothy and clover
AAy. two crops.
Third year: Pasture. plowsd in iall