The San Francisco call., 1897-11-23
in the arid and humid climates respect

in the arid and humid climates respect
lively; and, as l think, explains quite
fully The marvellous facts alluded to in the
telegraphic summary Of Professor Whit
ney's report.
II is there explained that as in arid
climates the formation OF clay III the
wealth ering process that accompanies soil
formation is very much less than In the
regions of summer rains, the soils are
predominanuy OF pulverulent or
sandy nature, and of great depth.
The relative absence of clay pre-
vents the formation of such "sub-
soils" as are formed in the East
by the washing down Of clay
from the surface soil. Hence both air and
plant roofs can and do penetrate much
mole deeply, and the latter can thus sup
ply themselves with much more both of
moisture and plant food than is possible
where compact subsoil lies at from six
to ten inches below the surface, ana
where, therefore, the feeding roots are
concentrated in the surface layer. Hence
six weeks drought in the East and in
Europe paTalyzes the active roots OF the
crops while. as is years experience
shows, hountiful crops may be harvested
where the roots can penetrate to four or
five times the depth, even with a six
months drought. And as there is no raw
subsoil' which, if turned up by deep
blowing, would in the East de-
priye the farmer of one or
two crops the California farmer can
as rule plow as deeply as he pleases ir-
respective of that consideration, although
in certain soils he should not go too deep
in order not TO waste moisture. As it is
wellknown fact that sand is an excellent
mulch the titled surface ordinarily con.
stitutes such good protection against
evaporation and consequent waste OF
moisture that no recondite causes for the
remarkable conservation OF m DISTURB dur
ing the long season OF drought need be
looked for.
But there is another cause for the con-
servation of moisture in such lands as the
Chino beet fields alluded to in the teIe-
grams. 1t Is the almost universal pres
ence in our lowland soils OF a certain pro-
norton OF ''alkalp' salts wnich prevent
evaporation 10 a very material degree.
Even reclaimed aikali lands need much
less irrigation than similar lands not con-
tanning the salts, and IN my plants are
tully satisfied with the moisture thus re-
tanned. In dry seasons the success of
crops where slight impregnation of al
kali exists often contrasts strikingIy with
The total failure in non-alkdline tracts
alongside. 1t is therefore quite easy 10
understand why, as is stated, "the soil is
always moist beneath the aikali crusts."
There certainly is no occasion to look
for the origin of this moisture in artesian
waters, as the report seems to intimate
the less as III strong alkali LANDS a water
tight hardpan usually intervenes at the
depth of three or four feet.
That the quick method of moisture de-
termination in the various soil layers by
electricity, devised by Professor Whitney.
will render good services in the farther
study of local conditions is unque stion-
able. But the main facts and their COM
paratiyely simple explanation have been
matters of record for years. and have
largely nodded the agricultural practice
or California. E. w. HILGARD.