STEPPLS, DESERTS, AND ALKALI LANDS. 613 



the alkali salts has been partially checked by the evaporation 

 through the roots and leaves of the crop ; whose thin foliage, 

 however, could not act as effectually as the dense, leafy mat formed 



First _ Foot Second 

 Depth of Soil Column 



Second 

 Depth of Soil Column 



by the dense growth of the native herbage on No. 1. Some evap- 

 oration from the soil surface itself continued, although it did not 

 suffice to injure the crop by the rise of the salts : and as at har- 



