Aug. 28, 1916 



Effect on Plant Growth of Sodium Salts 



863 



Table III. — Results of experiment 3 {igif), giving the effect of sodium carbonate in loam 

 soil and in Monterey sand on the germination and growth of wheat 



LOAM SOIL 



Series No. 



1 . 

 2. 



3- 



4- 



5- 

 6. 



7- 

 8. 



9- 

 10 

 1 r 



Total 



carbon- Num- 

 I ate salts ber of 

 recov- plants, 

 ered. 



Per cent 

 O 



Green weight of plants. 



Pot 1. 



Gm. 



791 

 72 5 

 535 

 588 

 666 

 497 

 255 



Pot 2. 



Gm. 

 o. 700 

 . 782 

 . 708 

 . 629 

 • 520 

 . 420 



•538 



•35 r 

 .077 



Total. 



Gm. 



I. 491 



I- 5°7 



1.243 



1. 217 



1. 186 



.917 



•793 



•351 



.263 



De- 

 crease 



in 

 yield 

 from 

 check 



pot. 



Per ct. 

 O 

 O 



17 

 *9 

 21 



38.5 



47 



76 



83 

 100 

 100 



MONTEREY SAND 



I 

 2 



3 

 4 



5 



6 



7 



9 



62 



89 

 96 



IOO 

 IOO 



IOO 

 IOO 



IOO 



1 In excess of sodium bicarbonate in soil at beginning of experiment. 



The; effect of sodium bicarbonate on wheat seedlings 



Experiment 4. — In order to determine the relative toxicity of the 

 carbonate salts when added to a soil in the form of sodium bicarbonate, 

 experiment 4 was undertaken in the summer of 19 14. The technique 

 of this experiment was the same as that of the experiments previously 

 described, the series of pots being triplicated. The soil used was of 

 the same type as that in experiment 2. The range of salts added to 

 the soil was greater than in the first two experiments, including series 

 numbered 8, 9, and 10, in which were added 0.80, 1, and 1.25 per 

 cent of sodium bicarbonate. Since there was no germination or growth 

 in these series, they have not been included in Table IV, which gives 

 a summary of the results of the experiment. 



