Oct. 8,1921 Relation of Sulphates to Plant Growth and Composition 107 



sulphur is not lower than in some of the others, but here the total yield 

 is small, and this often accounts for higher percentages of certain 

 elements. The jdelds in No. 3 and 6 are about the same; but the 

 sulphur content is higher in 6, although this culture depended only 

 upon the sulphur in the sand. No. 2 shows response in sulphur con- 

 tent to the higher concentration of sulphates in the media. The cor- 

 responding culture 12 in the other series does not show higher sulphur 

 content; and as the average sulphur content is lower in this uninoculated 

 series, it appears that the legume organisms might have some effect on 

 limiting the quantity of sulphur present in the clover hay. 



Table IV. — Data showing the sulphur-nitrogen relation in the portion insoluble in 



dilute acetic acid 



CaS04 



and 

 NaNOs. 



In soil treated with- 



NaNOa. 



Na2S04. 



NajSOi 



and 

 NaNOs. 



Average. 



Ratio 

 of Nto 

 S in the 

 insolu- 

 ble por- 

 tion. 



Aver- 

 age 

 ash 

 con- 

 tent. 



Crop I : 



Percentage of N insoluble in 



acetic acid 



Percentage of S soluble in 



acetic acid 



Percentage of S insoluble in 



acetic acid 



Crop II: 



Percentage of N insoluble in 



acetic acid 



Percentage of S soluble in 



acetic acid 



Percentage of S insoluble in 



acetic acid 



Crop III: 



Percentage of N insoluble in 



acetic acid 



Percentage of S soluble in 



acetic acid 



Percentage of S insoluble in 



acetic acid 



Crop IV: 



Percentage of N insoluble in 



acetic acid 



Percentage of S soluble in 



acetic acid 



Percentage of S insoluble in 



acetic acid 



Inoculated series, Medford loam: 

 Percentage of N insoluble in 



acetic acid 



Percentage of S insoluble in 



acetic acid 



Uninoculated series, Medford loam : 

 Percentage of N insoluble in 



acetic acid 



Percentage of S insoluble in 



acetic acid 



Per a. 

 2. 26 



.08 

 •13 



I. 70 

 . II 

 .09 



1.78 



•13 



.09 



2.05 

 .19 

 . II 



Per ct. 



2. 24 



.07 

 . 12 



1-57 

 .06 

 .08 



I. 76 



•05 

 .09 



1.97 

 .09 

 •13 



Per ct. 



2.58 



.09 



I. 64 

 .07 

 .09 



1.87 



I. 



.16 

 . II 



Per ct. 

 2.15 



.07 

 •15 



1-73 

 . II 

 .09 



1. 85 

 . II 

 .09 



2. 12 

 .18 

 . II 



Per ct. 

 2.31 



• 13- 

 1.66 



m-1 



1. 81 



>i9. 4 



•93 

 2.03 



•"5 



2. 20 

 ■125 



I. 21 

 . II 



ni-s 



► 17. 6 



Per ct. 



9.94 



7-31 



6-95 



54818°— 21- 



