868 



Journal of Agricultural Research 



Vol. VI, No. 22 



Table VI. — Results of experiment 6 (1Q14), giving the effect of sodium sulphate on wheat 



seedlings 



^ SO 



X 

 $ .60 



<o .40 



!• 



§ .oo t 



«■ ii li 88 



S 6 



S 3 /O 



iSER/ES NUMBEIfi?& 



Fig. 8.— Diagram of the quantity of sodium sulphate added to the soil in experiment 6, the quantity 

 recovered, and the total green weight of wheat obtained. The left-hand column above the series number 

 represents the quantity of sodium sulphate added and the right-hand column the quantity recovered. 

 The curve at the right represents the weight (in grams) of green plants from each series. 



In the preceding experiments it was found that this same sandy loam 

 soil absorbed an average of 77 per cent of the sodium carbonate, 85 per 

 cent of the sodium bicarbonate, and 15 per cent of the sodium chlorid 

 added. In this experiment with sodium sulphate it was found that the 

 amount absorbed was 53 per cent of that added. 



The toxicity of this salt was also considerably less than that of any of 

 the other salts mentioned. In the case where o. 1 6 per cent of the sulphate 

 was recovered, the yield was reduced only 20 per cent, while an equal 

 amount of sodium chlorid reduced the yield 49 per cent. The percentage 

 of germination was not affected in the case where 0.35 per cent of sodium 

 sulphate was recovered, but it was noticed that the time required for 

 germination was materially lengthened as the percentage of the sulphate 

 increased. 



Figure 8 shows graphically the results given in Table VI. 



