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. 



Loughridge,^ 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 : — 



Chop 



NasSOi 



NasCOa 



NaCl 



Total Alkali 



Grapes . . . 



40,800 



7,550 



9,640 



45,760 



Oranges . . . 



18,600 



3,840 



3,360 



21,840 



Pears . . . 



17,800 



1,760 



1,360 



20,920 



Apples . . . 



14,240 



640 



1,240 



16,120 



Peaches . . . 



9,600 



680 



1,000 



11,280 



Rye .... 



9,800 



960 



1,720 



12,480 



Barley . . . 



12,020 



12,170 



5,100 



25,520 



Sugar beets 



52,640 



4,000 



5,440 



59,840 



Sorghum . . 



61,840 



9,840 



9,680 



81,360 



Alfalfa . . . 



102,480 



2,360 



5,760 



110,320 



Saltbush . . 



125,640 



18,560 



12,520 



156,720 



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

 tures. California Agr. Exp. Sta., BuL 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., BuL 113. 1907. 



