18 
SOILS AND ALKALI. 
water in passing through the soil dissolves it, and when 
this water is again brought to the surface, it carrries with 
it the saline matters—in our case the alkali; and as it is 
evaporated from the surface, leaves this alkali as a white 
crust or coating on the soil. The alkali is not peculiar to 
Colorado or this arid region, but is found in many coun¬ 
tries—Greece, Patagonia, India, California and other places. 
It is easily seen that the more water that is evaporated 
from the surface of the soil, the more alkali will be drawn 
to the surface within a certain limit, which is a problem 
for another section of the Experiment Station; a 
greater rainfall will bring up a larger amount 
of alkali, provided the rainfall is not sufficient to 
wash the alkali into the water-table before alluded 
to, and so be washed or carried off as drainage. It 
will be readily seen that it will make no difference in 
what form this water is, whether rain or irrigation, that 
the same result would be true. The amount of this water 
to accomplish one or the other of the above results will de¬ 
pend largely upon the soil, as clay or sand, and upon the 
underlying strata. There must be an inverse relation be¬ 
tween the rainfall or irrigation and the prevalence of the 
alkali in the soil. 
The alkali effects plants in two ways: First, by 
bringing the upper roots and crown roots of the plants 
grown upon the soil in contact with its corrosive action; 
second, by destroying the tilth of the soil Alkaline solu¬ 
tions render the soil like well-worked potter’s clay, instead 
of the ffocculent condition that it should be in, with in¬ 
numerable openings and channels for the passage of the 
rootlets. 
The composition of the alkali will vary with the local¬ 
ity from which it is obtained. 
The following account is from the Department of Ag¬ 
riculture, 1870, p. 96 : “ Dr. Edward Palmer brought to 
the laboratory, from Western Kansas prairies, a sample of 
