SALINITY FACTOR 289 
grown under saline conditions will be greater if crops such as 
sugar beets or cotton having high salt tolerance are planted rather 
than field beans, which have a very low salt tolerance. Likewise 
with forage crops, better results may be expected if some of the 
salt-tolerant grasses are grown instead of salt-sensitive clovers 
such as Alsike, red, and Ladino varieties. With vegetable crops, 
garden beets, asparagus, and spinach will be more successful than 
green beans or celery. In selecting salt-tolerant crops for a given 
area, it is important to understand that climatic factors may pro- 
foundly influence the response of plants to salinity. For this 
reason, the choice of suitable salt-tolerant varieties will depend 
upon local climatic conditions. 
Summary 
The quality of water supplies becomes a more and more 
critical factor with the increasing need for additional water for 
irrigation in semi-arid and arid areas. The major characteristics 
which determine water quality are: total concentration of soluble 
salts, concentration of sodium, concentration of bicarbonate, and 
the occurrence of minor elements such as boron in toxic amounts. 
The reuse of waters returning to the stream after diversion for 
irrigation commonly results in a significant increase in total 
salinity. In some cases, increased concentrations of sodium, 
chloride, and other elements may affect soil characteristics 
adversely or may be directly injurious to plant growth. For these 
reasons, it is important to determine the characteristics of all 
questionable waters. With this information at hand, the possible 
solution of the use of such waters depends upon the use of appro- 
priate soil- and water-management practices and the selection of 
salt-tolerant crops. 
REFERENCES 
1. Howard, C. S. 1953. Irrigation and water quality. Reclamation Era, 
30, 1-2, A, 
2. Paulsen, C. G., Chief Hydraulic Engineer, U. S. Geological Survey. 
1954. “‘What to do about our growing demands for water.’ Presented 
at the 12I1st meeting of the American Association for the Advancement 
of Science, Berkeley, California. 
