Oct. 4, 1915 



Effect of Alkali Salts in Soils on Crops 



19 



tionately more toxic than in the other soils. This is exactly the same 

 result that was obtained in 1913 in the experiments already described. 

 In sand the carbonates seem to be nearly as toxic as the chlorids, while 

 in the other soil they are very much less injurious. 



KNOt 



loooppm. 



»S(fOs)i 



zjoooppm. 



3.000 ppm. 

 ChecK^NoSalt 



t.oooppm 



s.oooppin 



90ooppm. 



10 000 ppm 



i.oooppm y.opoppm e.oooppm. 



. = One plant. — = 0.1 gm. dry matter. 

 Fig. 9. — Diagram showing the number of wheat plants up and dry matter produced in 14 days on coarse 

 sand with potassium nitrate, magnesium nitrate, and sodium nitrate in different combinations and 

 concentrations. 



VatS04 



'toooppm. 



z,oooppm 



s.oooppin. 

 ChecK^NoSalt 



A.oooppm. 



s.oooppin. 



i.oooppm. loooppm. &oooppm 



. = One plant. — = 0.1 gm. dry matter. 



9.000 ppm 



10 000 ppm 



Fig. 10. — Diagram showing the number of wheat plants up and dry matter produced in 14 days on coarse 

 sand with potassium sulphate, magnesium sulphate, and sodium sulphate in different combinations 

 and concentrations. 



Figure 8 shows the same relationship between the chlorids as was 

 brought out in figure 3. It also shows that these salts are in injurious 

 lower concentrations in sand than in other soils. 



The nitrates are shown in figure 9 to be slightly less injurious than the 

 chlorids in figure 8. The sodium salt is again shown to be more injurious 

 than the others. 



