36 



Journal of Agricultural Research 



chlorid, and magnesium chlorid in a concentration of 8,000 p. p. m. was 

 over 20 days, which was nearly four times as long as the time required for 

 seeds to come up where no salt was added. The period of germination 

 was less with the sulphates and carbonates than with the other salts. 



The time of germination of different crops in the presence of sodium 

 chlorid, sodium carbonate, and sodium sulphate in combination is shown 

 in figure 39. Where no salts were added, the time varied from about 

 4>< days for barley to nearly 8 days for sugar beets. The same general 

 relation between the germination of various crops continued with the 

 different concentrations of salts. Alfalfa was least affected by salts of 

 any of the crops in the length of its germination period. 



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



Concentration of salts in p. p. m. 

 Fig. 36. — Curve showing the number of days for wheat plants to come up in College loam, Greenville loam- 

 Average of 13 salts. 



and sand with different concentrations. 



Figure 40 shows the effects of individual salts on the germination 

 period of different crops. This brings out again the fact already men- 

 tioned, that the same relative toxicity of salts does not hold for all crops. 



HEIGHT OP PI.ANT 



Figures 41, 42, 43, 44, and 45 show the effect of various factors on the 

 height of plants. This is probably one of the best means of comparison 

 for young plants of this kind. 



Plants growing in sand were not so high in any case as those growing 

 in other soils; in the Greenville loam they were shghtly higher than in 

 College loam. The height in loam was greater with 1,000 p. p. m. of 

 salt than where no salt was added, but above this point the height 

 decreased considerablv as the concentration of salt increased. In sand 



