The enterprise., 1915-08-26

given to description Of the time o
blowing for spring wheat, but is a
applicable to oats and corn. The ex
periments were performed at Akro
(Colorado,) field station, but til.
deductions are general and usefu
throughout the entire Great Plain
area. The experiments extende,
over period of six years. from
1909 to 1914, inclusive, and during
those years the function in rainfall
was as great as would be expected
through any like period.
It was found that there was wild
er variation in the precipitation Of
the fall and winter, when the moist
ure should be stored, than during
the growing months. Rains in
August and early September invari-
ably produced a growth of weeds
which usually exhaust the valuable
moisture supply. The loss Of moist
ure which has penetrated to great
er depth than three inches, after
the weeds are dead in the fall and
before growth starts in the spring,
is almost neglible. Either from
land fall plowed or from that COW
cred with stubble, light precipita-
ton evaporates unless it falls as
snow, which is blown into drifts un-
til a considerable quontity has accu-
mulated. AS 10 inches of light snow
are equivalent to only one inch OF
rain, and one inch of rain pene-
trates the soil to the depth of six
inches, it will be readily seen SHOWS
of one to two inches supply very
small amount of moisture a greater
part of which will be lost by evap-
oration. Every effort should be
made, therefore, to conserve the
moisture which falls either while
the crop is on the land, or while the
land is lying idle.
Early fall rains will be used by
weeds unless the land is cultivated.
Heavy winter SHOWS may occur, but
they are likely to blow off the fields
unless there is either stubble or an
uneven surface to hold them. The
time and method of cultivation,
:nen, should be planned to prevent
weed growth, and still leave the soil
or stubble in such a condition that
it will hold the maximum snow.
However, the period when labor is
available will also be an important
factor in determining the time of
plowing. When labor is scarce, cul-
tivation other than plowing which
will kill weeds, and can be done
rapidly, may be resorted to. If
this cultivation leaves the stubble
on the surface or leaves the surface
rough enough to hold the snow, it
may be of greater value than plow-
ing. Disking or listing in the fall
are the methods most commonly
used.
Spring Flowing Eliminates Weeds.
The amount of moisture in the
ground in the spring is only one of
the factors in producing grain
crops. Weeds growing with the
crop may use enough water to de-
crease the grain yield. 1t is esti
mated that one ton of Russian this
ties uses 65 per cent as much water
as it would take to grow ton of
unthreshed wheat. 1t was found
that fall plowing at the Akron sta
tion is especially favorable to weeds
starting with the grain. Flowing in
the spring, however, thoroughly
eliminates the weeds, and if done
Immediately before seeding gives
the grain crop start before the
weeds commence to grow The
ideal cultivation would prevent
weed growth in the fall, leave the
land in such condition that it would
retain the maximum snow in the
winter, and retard the termination
of weed seed until the crop starts
in the spring.
Possibly this may be accom-
plished by disking in the fall and
plowing in the spring, or listing in
the fall and bursting the ridges in
the spring may be more practical
bic. Early fall plowing is effective
in that it destroys weeds which use
the early fall precipitation, but it
does not leave the land in condi-
tion to retain the snow in the Win
ter, am. it gives the weeds an op-
portunity to start before the crop.
In deciding the time to plow, the
and disadvantages of
both spring plowing and fall plow-
ing must be taken into considera-
ton. Heavy rains in August indi-
cate that fall plowing should be
done, as the gain of moisture during
the winter by the stubble land prob
ably would not equal the loss of
moisture taken by the weeds in the
fall. If only light rains occur, how
ever the moisture in the soil pro-
duced by these rains probably
would be more than offset by the
greater quantity Of snow held by
the stubble during the winter, and
the reduction of the weeds in the
crop. Spring plowing would then
be better. The availability of labor
in the fall will influence the amount
OF ploWing done, but greater eff
fort should be made to do the plow-
ing if there is heavy precipitation
than IT the rainfall is light. The
only advantage in late fall plowing
is that the amount of spring labor
in preparing the seed bed is re-
duced. This advantage however,
may be offset by reduction in the
yield.
In deciding when a field should
be plowed, the question of whether
a greater amount of water will be
ON L.