Imperial Valley press., 1921-07-29
I'M P D RTAN7 |
SOIL TEST
IS MADE
HERE
Experts to Determine If
Water Content of Ground
Is Changed After Irriga-
ton by Cultivation.

Efforts TO find a solution of the
question of whether evaporation OF
water in the soil is increased or de-
creased by the cultivation during the
growing period of the crops are being
conducted on the A. A. Cook ranch.
three miles west and one mile south
of Brawley by the irrigation investiga-
ton section of the college of agricul-
ture of the University Of California,
in connection with the Imperial County
Farm Bureau.
Should it be proven that evaporation
is greater because of cultivation of
crops after they have been irrigated It
will mean great saving OF time ana
money to farmers, especially in sec
tions like Imperial Valley where bene-
fetal rainfall is practically nil, and 1t
will mean that cultivation on which so
much time is spent may be abolished
without affecting the crops. On the
other hand, if it is proven that culti-
walton aids in conserving the water
content of the soil it will show that
the efforts of the agriculturists of this
section, where it is almost universally
practced,. shave not been wasted.
The theory of the cultivation idea is
that when land is broken up after it
has been irrigated, that the coating
of fine soil which is produced on the
surface of the land serves as an lnsu-
lator aehinst the heated air and keeps
the suns rays from drying up the soil
below the cultivated surface.
MANY tests have been made in an
effort to conclusively determine the
effect of the soil after it has been IT.
rigatd. but from reports submitted IN
various sections of the country the
answer has been extremely unsatls-
factory. In some cases the field tests
have given rise to the belief that evap-
Grafton is decreased by cultivation, but
laboratory tests of the same soil
samples have shown the contrary to
be true, according to experts. Be-
cause of the fact that soil conditions
in various sections are so vastly dlI-
ferent the state university agrlcultur-
lists decided to make special tests IN
the Imperial Valley, and they expect
to solve the problem here.
Since the beginning of the applica-
tion of scientific principles to agricul-
ture the question of evaporation has
been one that has received great
deal of attention from experts and in
spite of much research no satlsfac-
tory solution has been reached, al
though the predominant theory is that
evaporation is diminished by cultlva-
ton after irrigation.
Four plots of ground, each 80 by 10
feet, have been laid out side by side
on the Cook ranch, and each was plow-
ed and finished off with disc harrows.
but nothing was planted on any of the
plots. The ground is laid out in such
manner that plots ! and 3 can be IL
rigated and plots and left dry, the
plan being to cultivate plots l and 3
after they have been irrigated once a
week for five yeeks and then once a
month for three or four months. Water
was turned on the land a few days ago
and today plots and 3 are being cul-
tivated for the first time under the
direction of farm bureau men. The
experiment was begun by F. j. Vel
never of the state university, who
instructed the farm bureau men in
the method of conducting the tests.
After each test the amount of water
in the soil of each plot will be deter
mined by the weight of the soil, Ga
samples of which will be taken every
time the land is irrigated and cult
vated. Two samples will be taken
from each of eight holes on each plot
of land, one sample being taken at a
depth of about three feet and another
at a depth of about six feet. After the
weights have been taken and other
minor tests made by the local farm
advisor and his assistants the samples
will be sent to the state university foi
exhaustive laboratory tests which vii
determine the exact water content OF
each sample.