Oct. 4, 1915 



Effect of Alkali Salts in Soils on Crops 



33 



The effect of individual salts is shown in figure 32. A comparison of 

 this graph with figure 27 shows that the dry matter is affected by the 



Fig. 32.— Curve showing the dry weight of wheat plants germinating in College loam, Greenville loam, 

 and sand containing various salts. Average for all concentrations. 



salt in just about the same way as the germination. The greater relative 

 toxicity of the carbonates in sand than in loam is again brought out. 



1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000 10,000 

 Concentration of salts in p. p. m. 

 Fig. 3j.— Curve showing the effect of various combinations of salts in different concentrations on the 

 amount of dry weight produced. Average of 15 combinations of each 3 salts. 



The action of each three salts used together is shown in figure 33. 

 With the exception of potassium carbonate, sodium carbonate, and am- 



