Oct. 4. 1915 



Effect of Alkali Salts in Soils on Crops 



43 



TabIvE XIV. — Effect of various cations on germination and growth of wheat. Average 

 forj. ■■ 



soils and 10 concentrations for each soil 



A comparison of the various data presented in Tables XIII and XIV 

 brings out clearly the fact that the injurious effects of the alkali salts in 

 soils may be attributed more to the anion, or acid radical, than to the 

 cation, or basic radical. All the chlorids gave results very similar to 

 each other. The same may be said of the sulphates and nitrates. The 

 different salts of sodium or potassium, on the other hand, differed greatly, 

 according to the acid radical combined with them. This is just opposite 

 to the conclusions of Kearney and Cameron (13) based on solution 

 cultures. 



RELATION OP MOLECULAR WEIGHT IN TOXICITY 



A number of workers have considered the toxicity of various alkali salts 

 to be proportional to their osmotic pressure. In order to determine 

 whether this were true, the different salts which had been tested were 

 arranged in the order of their toxicity and the molecular weight of each 

 placed opposite to ascertain whether there was any relation between the 

 two. Of course, it is understood that the lower the molecular weight of 

 a salt the more molecules there are in a solution containing a given per- 



