The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1908-02-16

L.
much lower the first thermometer sinks
than the second, showing that dew is
caused by the radiation of the heat of
the earth. and not by the general cool
ness of the atmosphere.
The Two Problems.
For successful arid farming. two
problems are TO be solved: First, to
catch all the rain of winter; second.
to keep it from evaporating during the
summer The first object is attained
by deep blowing in the fall. In this
way about eighty-five percent of the
winter moisture may be retained till
spring. Then the land should be har-
rowed, so as to form a thick, fine
mulch of Dulverized soil at the sur
face This mulch viii prevent evapO-
ration. Therefore the narrowing should
be repeated not long after every RAIN
fall. No weeds should be permitted to
grow. since they consume the soil
moisture They should be destroyed as
fast as they appear. In this way the
water caught in the winter may be
kept in the ground during the sum-
mer, to be used as needed by the grow
ing plants.
Storing the Water.
In order to store water in the soil,
space must be provided in which it
can be held until the plant roots drink
it in The soil is composed of rock
grains of all sizes variously compact
ed or thrown together. The soil must
be made less like a solid substance
and more like a sponge in order to
hold the moisture. 1t must be filed
with spaces between the grains. so
that it has plenty of the capillary
tubes in which the moisture can be
held. The more of these tubes, or
| spaces there are, the more water the
soil will retain. The surface soil must
therefore be ploWed or loOsened in
some way. This may be done with d
disc pillow or a mold-bOard pillow; but
the sub-soiI plow should also be used,
since deep blowing is generally neces-
sary in order that sufficient moisture
shall be stored. When the soil is thus
plOWed the torrential rains which fall
| in summer or autumn and the snow
! or sleet of winter viii sink into the soil
| instead of running off the surface.
How Moisture Is Lost.
Soil moisture is lost in two ways:
ID the free water percolates or sinks
downward until it is lost to the roots
of the plants. or 90 the water is lifted
II
by capillary attraction to the surface
of the soil, and escapes into the air by
evaporation. In the arid west. 1T
seems improbable that much if any of
the soil water is lost by downward
percoatiOn through the soil in sum-
mer since the summer heat tends to
bring il to the surface. The surface
soil becomes drier in the hot weather
than that lying Immediately below it;
and then the moisture rises through
the capillary tubes into the upper lay
ers. TO keep this water from coming
to the surface, we must enlarge the
capillary tubes, and this can be done
by repeated cultivation and by form
ing the loose and open "dust mulch
as the top layer The rising water is
stopped when this surface layer is dry,
but not if it is wet. The effect of our
| dry, hot summer wind is to scar the
top layer, and. if it does not bake. to
form a layer impervious to the rising
water But if the soil has too much
clay and is permitted to dry naturally,
it will bake and crack. and through
| these cracks the moisture will escape.
! University of Utah, Feb. Il, 1908.