Effect of A Ikali Salts in Soils on Crops 



35 



up, which in this case were only those in low concentrations. At the same 

 time there might be considerable germination in the high concentrations 

 of less toxic salts, but the time of germination was increased. Thus, the 

 average time of germination might appear to be longer in the less toxic 

 salt, when in reality this would not be the case. 



Figure 36 shows the time required for wheat to come up in Greenville 

 loam, College loam, and sand containing salts in concentrations up to 

 10,000 p. p. m. The results are the average for 13 different salts. The 

 time required to gemiinate where no salt was present varied from about 

 5>^ to 6K days with no salt and from io>^ to 15 days with 10,000 p. p. m. 





Sugar beets Wheat 



Corn Field peas Oats 



Barley Alfalfa 



Fig. 35. — Curve showing the effect of sodium chlorid, sodium carbonate, and sodium sulphate on the dry 

 weight from seeds of various kinds. Average for concentrations from 1,000 to 10,000 p. p. m. 



of salt. The time was doubled by the presence of from 6,000 to 8,000 

 p. p. m. of salt. 



Figure 37 shows the effect of individual salts on time of germination 

 iu the three kinds of soil. Calcium chlorid, magnesium chlorid, and 

 sodium chlorid retarded germination most in Greenville soil, while sodium 

 nitrate came next. 



In sand the salts did not retard germination as much as in loam. 

 This is because there was no germination whatever in sand with the 

 highest concentration. There was no germination in sand when ammo- 

 nium carbonate was added, even in as low concentrations as 1,000 p. p. m. 



The results where three salts were used together are shown in figure 

 38. The average time of germination with potassium chlorid, calcium 



