Rocky Ford enterprise. (Rocky Ford, Colo.) 1887-1950, 1912-02-23
ALKALI
SOILS
BY 2. E. ADAMS

Alkali is problem entirely confined
to arid or semi-arid regions, and is
simply the accumulation in the soil
OF those salts which form in the pro-
gressire weathering OF the rock grains
comprising the soil. In all parts of
the country the soil particles are con-
stantly breaking down and liberating
the salts contained in them.
From the standpoint of plant
growth these salts are OF two kinds.
one beneficial and needed for plant
development, the other of negative or
even injurious character. The first
will be retained in the soil to a great
extent, the second is very soluble i'll
water and in region OF sufficient rain
fall will be taken into solution and
pass into the springs and brooks, and
through these to the ocean. But
when the rainfall is light the salts are
lett in the soil, and year by year, will
accumulate until the total amount
present will be so great that ordinary
plant growth is impossible. The
abundant rainfall of the eastern sec
tions accounts for the absence of all
kali. There the rainfall is sufficient
to leach out the soluble alkali salts as
fast as they are formed But certain
plant foods also are soluble and these
will be lost along with the alkali, SO
that while the injurious salts are re-
tanned in arid sections because OF in
sufficient rains to wash them out, at
the same time the soluble plant foods
are retained. This explains the great
richness of the arid section when
brought under cultivation by means
OF irrigation, for along with the ac-
cumulation of alkali salts are plant
foods which have been liberated and
stored for the future.
Alkali soils differ from soils CON
tanning salts laid down, as old sea
formations, or wirom soils treated to
an occasional overflow from the sea.
In cases of this kind there is little
present which the plant can use, for
common salt, EPSON salts, and the
like predominant. and these are OF an
injurious nature and are far in excess
OF the plant foods. q
In order to determine the nature
and extent of alkali soils and their
agricultural possibilities, a chemical
analysis is necessary. Such analyscs
when based on samples secured by
systematic sampling OF the field iii
question to different depths and at
different points show the extent and
nature of the salts. 1t will prove a
far quicker and more reliable guide
than the trial OF growing crops. For
not only will the tests show condi-
tions as they exist, but the remedy
usually will suggest itself from a study
of the land when sampling and from
the results OF the analyses. For in
stance. ii the salts are coming from
beds deep down in the soil through
the action OF water, the ANALYSIS will
be the surest way OF finding it out.
In connection with the chemical work
must come study OF the soil forma
ton, the general topography of the
country aud the irrigation water. \
little study of the conditions which
are bringing, or have brought about
an extess OF alkali usually will show
the methods that must be adopted to
offset them.
Alkal salts do not remain station
ary in the soil. They move up and
down in the soil ayers according to
the moisture conditions. Hence, at
different periods the maximum
amount OF salts will be at different
points. Following heavy winter rains
or applications OF irrigation water the
salts are dissolved in the water and
carried down with it into the lower
levels OF the ground When the wat
er begins to reasccnd and evaporate
the salts are carried up to the surface,
or to the point where evaporation Is
going on and redeposited. Ii.
though, the water passes into gravel
layers or into streams the salts will
be carried with it away from the
land. Where this condition occurs
naturally. there is never alkali accum-
ulations.
The presence OF alkali salts comes
about in two ways on land which is
/ II. ID
ing the land either as irrigation. seep-
age or underground flow, or (b) from
deposits of salts in the soil which are
brought UP from below by the move
ment OF the soil moisture. In the lat
ter case the salts can only move by
their own power to a height OF about
three to six feet depending on the
character OF the soiD. In oSder to
rise from a greater depth, Whether
they be in the water table or deposit
ed in beds, communication with the
surface can only be brought about
through several successive periods OF
depositing and going into solution,
the amount of water being so regu-
lated that it does not carry the salts
back to their original depth each time.
The deeper the salts are buried the
smaller chance do they have to reach
the surface. Alkali below ten feet
where ample irrigation is given with
out swamping the land will success
fully guard AGAINST this.
A study of the extent of alkali
shows that TIE quantity of salts var
les in different parts OF the same
field. Low depressions where the
rainfall gathers will cause much more
alkali to come to the surface than
where there is less amount OF wat
er In sloping valleys it occasionally
happens that the salts from the ad-
jacent hills are deposited to such an
extent that broad stretches OF alkali