Pullman herald. [volume] (Pullman, W.T. [Wash.]) 1888-1989, 1910-07-29
SOIL TILLAGE
Three Great Difficulties of Single
Crop System Becoming Manifest
in This State
(By Prof. r. W. Thatcher, Member
w. S. C. Experiment Station Staff.

|
ern Washington always results in
three great difficulties: Cd Il q land
becomes thoroughly seeded with
weed seeds, and immense grOwths of
weeds threaten to destroy the crops
GU the soil becomes depleted of
decayed vegetation and washes bad
ly in the winter or blows away in
the summertime; CD the size of the
farm increases until many farmers
own more land than they can farm to
best advantage.
We have reached a state in this
part of the state when all three of
these difficulties are becoming man
ifest. The system of tillage we will
have to follow will have to be plan
ned largely to meet these difficulties.
Many things which we could other
wise do will have to be left out and
some system of tillage which might
be ideal if conditions were more fav-
orable, will have to be modified in
order to meet the difficulties just
mentioned.
Fortunately the system of tillage
which makes the best use of tho
soil moisture usually accomplishes
also the best results 80 far as other
needs are concerned. In the eastern
region, the chief reason for the adop-
ton of the so-called "dry-farming
methods lies in the fact that our rain
fall is light. There is no place in
Eastern Washington where the sup
ply is over abundant, and in many To-
calities there are frequent seasons
when the total rainfall is below that
needed for the production of the
largest crops.
A discussion of toll tillage will
therefore consist chiefly in the de-
scription of the best methods of con-
serving soil moisture. In the parts of
the state where dry-farming is prac-
ticed most Of the rainfall comes dur
ing the winter and early spring
months. The first necessity in MAX
ing the best use of moisture is to get
as large portion of it as possible
stored in the soil Our experiments
have shown that if the soil is left
untouched after harvest so that the
surface bakes over and crusts, a
considerable portion of the winter
rains runs off from the surface. This
is complete loss, as the water that
runs away in the rivers and streams
is of course of no value to the crops
that are to be grown. The first prin-
cipal in conserving moisture is there
fore to have the soil as loose and
open during the winter as possible.
For this purpose fall blowing is es-
pecially recommended. If it is impos-
sible to pillow, then discing should be
practiced. The looser and deeper the
soil can be stirred in the fall, the
larger the proportion of winter mois-
ture will be that is absorbed.
The next step in the conservation
of soil moisture is to prevent it's
evaporation from the soil in the
spring and summer. This is accom-
pl1shed by the maintenance of
mulch of loose, dry earth on the sur
face of the ground. Our demonstra-
ton apparatus shows that this mulch
is most effective if maintained to
a depth of two and one-half to three
inches. If shallower than this, more
moisture is lost by evaporation. If
deeper mulch is maintained the dry
earth is too deep to permit seeding
the grain through it into the mt DIST
soil beneath
For fall-seeding grain the best
practice therefore is to disc the soil
early in the spring, then plow in
early summer to a depth of not more
than five inches, following the ploW-
ing Immediately with a sub-surface
packer in order to pack the soil back
so that a shallow mulch may be es-
tablished by surface cultivation. If
this mulch is once established and
we'll maintained fall wheat can be
seeded early in Septmber through the
mulch directly into the moist earth
beneath. 1t will then terminate rap
idly and make sufficient growth to
insure a good stand of grain and to
more successfully smother the weeds
which grow in it.
If, however, the ground is to lie
over for spring seeding the next year,
the tillage which has just been out
lined will make the soil too fine and
loose on the surface of the ground,
and much of the surface soil will be
blown away by the wind, or washed
from the hillsides by the rain in the
winter. Under such conditions there
fore, is is probably better to disc