Deming graphic. (Deming, N.M.) 1903-1948, 1913-08-08

By S. r. Mitchell, Asst. Chemist, n
NJ. State College

VI. state Colege
By many farmers the word cal
kali" is used to signify any salt APP
pearing in the soil or deposited on it
by the evaporation of water. The
above is rather too liberal definition
IN the minds of most scientific men,
who have to deal directly with the
material.
All OF those mineral salts which
are III the class Of the so-called read
lily soluble salts in water, are usually
called alkalis; and these are usually
considered from the standpoint Of
white or black alkali.
ORIGIN AND COMPOSITION
When rocks are dccomposed by
atmospheric agencies such as heat,
cold, water and air gases, they form
sand, clay, other simpler compost
tons, rocks and alkaliS. Most Of
the alkaliS Are combination of So
dunn or potassium with chlorine or
with sulphur and oxygen or with nj
trogen and oxygen, or with carbon
and oxygen to form the so-caled
chlorldes, sulphates, nltratcs or car
Donates of sodium or potassium. The
most common alkalis are those Of the
sodium salts.
BLACK ALKALI
Sodium carbonate (sal soda) or
sodium bicarbonatc (baking soda)
usually constitute the sum and sub
stance of black alkali, although the
rarcr carbOnates of potassium, lithi-
nm or of any of the alkali metals
might also be included in this class.
The BLACK" alkali gets its name
from the peculiar corrosive effect on
vegetation coming III contact with il;
the result of the corrosion is n dark
stain on the plants affected, and Of
ten on the surrounding soil.
WHITE ALKALI
All alkali, excepting the black"
variety is called white" alkali. In
this category might be mentioned So
dium chloride table salD, sodium
sulphate Cglauber salt), sodium nj
tratc tsaltpeter), the corresponding
potassium salts, magnesium chloride
aud magnesium sulphatc Epson
>alu. 4 few other salts are to be-
classcd as white alkahs. but these are
not so common.
Limestone and gypsum are some
times enormously classed a. alkalis.
because they are deposited By. some
water on cvaporatior These Two
substances are not readily soluble in
water alone, but are made more solu-
bic by the presence of other salts
and gases.
HARMFuLNESS OF ALKALIES
a small amount of either black or
white alkali in the soil, or water used
for irrigation acts as a food for the
plants and is not harmful, but large
amount usually has bad effect
upon crops. II is difficult to specify
the exact limit of endurance for each
crop, because so much depends upon
the kind Of soil and method Of cul-
tivatlon. The limit set for the alkah
tolerance of a certain crop in one 10.
caity might be quite tolerable by the
same crop in a different locality, be-
cause one soil is sandy loan while the
other is clay.
LIMITS OF TOLERANCE
DR.. Hilgard of the California en-
pertinent station, Whitney, Cameron
and Means of the bureau of soils.
United States agricultural depart
ment, and other station men. have
set approximate percentages Of al
kali tolerance; but there are so many
factors influencing crop productions
in alkali soils tina, these so-callcd
limits are coming TO mean less and
less with each experiment.
The tolerance limits usually recog-
nzed in a soil Of average fertility
and drainage, where special work has
not been previously done to establish
limits, has been about 0.O5 percent of
black alkali, OBS percent of sodium
chloride, 100 percent sodium or mag
nesium sulphate
RECLAMATION OF ALKALI LAND
Alkali lands that have not been