ALKALI SALTS 



395 



Of the cereals, barley and oats are the most tolerant, 

 these being able in some cases to produce good crops on 

 soil containing two-tenths per cent of white alkali. Of the 

 forage crops, a number of valuable grasses are able to 

 grow on soil containing considerably more than two-tenths 

 per cent of alkali. Timothy, smooth brome, and alfalfa 

 are the cultivated forage plants most tolerant of alkali, 

 although they do not equal the native grasses in this 

 respect. Cotton also tolerates a considerable amount of 

 alkali. 



Lough ridge, 1 after experiments and observation for a 

 number of years, has obtained data regarding the resist- 

 ance of various crops to the several alkali salts. His 

 results are given in part below, expressed in pounds to 

 an acre to a depth of four feet : — 



1 Loughridge, R. H. Tolerance of Alkali by Various Cul- 

 tures. California Agr. Exp. Sta., Bui. 133. 1901. See also 

 Kearney, T. H., and Harter, L. L, Comparative Tolerance of 

 Various Plants for the Salts Common in Alkali Soils. U. S. D. A., 

 Bur. Plant Indus., Bui. 113. 1907. 



