J. W. BOULTBEE. CLXXI. 
“Tt is evident that if alkaline waters are used for irrigating 
lands already more or less charged with alkali, the amount of the 
latter may be readily increased to an extent that may render the 
continuance of profitable culture impossible. As stated elsewhere 
and is that too well known to many irrigators, this not uncom- 
monly happens even when the purest water is used for irrigation 
—a very troublesome phenomenon which is popularly known as 
the rise of the alkali. The causes which lie at the bottom of this 
process have been fully shown by investigation made at this 
station. It results from the accumulation, near the surface and 
therefore within easy reach of the roots and root-crown of culture 
plants, of the alkali salts which for long periods have been accu- 
mulating in the depths of the subsoil, near the level to which the 
annual rainfall reaches, the amount of irrigation water used, 
being usually no more than is necessary to wet the land to a depth 
absolutely required for the welfare of the crop, but not sufficient 
to carry the alkali salts into the country drainage. The accumul- 
ated salts are dissolved and subsequently by surface evaporation 
of the water, are themselves carried near or to the surface, until 
the entire mass formerly distributed between 3 or 4 feet of soil 
and subsoil, is accumulated within a few inches of the surface, 
where they will do the most harm to vegetation. The injury to 
the latter being in the majority of cases due to a corrosion of the 
root-crown by the strong saline solution. 
“If, as is well known, this happens even when the purest water 
is used for irrigation, the evil must be aggravated i proportion 
to the additional amounts of salts carried into the land by the 
saline irrigation waters. In the case of some waters used for 
irrigation within the last few years, the alkali content has been 
so great that soils heretofore wholly free from alkali contamination 
have been converted into genuine alkali lands, incapable of being 
used for ordinary cultures but only for such as are tolerant of such 
salts. In several instances, this has been done, despite the warn- 
ing given by this Station as to the inevitable results of the use of 
such waters under any ordinary conditions or modes operating, 
