I02 



Journal of Agricultural Research 



Vol. XXII, No. 2 



concentration of sulphates on growth and nitrogen assimilation, and also 

 the relation of total sulphur content of the plant as influenced by available 

 nitrogen. The red clover and rape were used in this work. With clover, 

 the initial concentration of legume bacteria has been varied by inocu- 

 lating certain cultures, while others were not inoculated. 



Table I. — Analytical results with red clover on Medford loam soil 



Treatment. 



Weight 

 of air- 

 dried 

 clover. 



Sin- 

 S in soluble 

 acetic- in 

 acid acetic- 

 solu- acid 

 tion. I solu- 

 tion. 



Weight 

 of air- 

 dried 

 roots. 



Total 

 S in 

 roots. 



Total 

 Nin 

 roots. 



Ratio 

 of 



tops 



to 



roots. 



2. 64 



2. 77 



2. 74 

 2- 73 



Control: 



Uninoculated . . 



Inoculated 



NaNOs: 



Uninoculated . . 



Inoculated 



NaNOa and HaSOt: 



Uninoculated . . 



Inoculated 



Na!S04: 



Uninoculated . . 



Inoculated 



CaSOi: 



Uninoculated . . 



Inoculated 



NaNOs and CaSOi: 



Uninoculated . . 



Inoculated 



Gm. 



15-84 



31. 24 



17. 70 

 21- 29 



18.82 



23-35 



15. 00 

 20. 31 



16.49 



16. 6s 



14. 18 

 16.89 



.08 

 .07 



• 15 

 -17 



09 



Gm. 



6. 00 



7- 6s 



6.45 

 7.80 



7. 60 

 7. 10 



8.60 

 8.20 



6. 10 

 6. 20 



P.ct. 



2. 39 



3. 92 



In the first experiment Medford loam soil, designated as soil B in the 

 previous publication (4), was used. This soil was heated in an electric 

 oven where the temperature was gradually raised to 120° C. and main- 

 tained for six hours. This was to destroy the legume bacteria present 

 in the soil. Four kgm. of soil, after being mixed with the different fer- 

 tilizers, were placed in paraffined clay pots and carefully seeded to red 

 clover. One series was inoculated with Bacillus radicicola Bey. The solu- 

 tion for inoculation was prepared by removing the growth of organisms 

 from a culture and mixing with water. Each inoculated soil culture re- 

 ceived a definite number of cubic centimeters of the bacterial solution, 

 concentrated where the seeds were placed. The amount of different fer. 

 tilizers added per pot was as follows : Sodium sulphate (NajSO^) , 3 gm. ; 

 sodium nitrate (NaNOj), 2 gm. ; calcium sulphate (CaS04.2 H3O), 3.75 

 gm. ; and calcium carbonate (CaCOg) , 3 gm. The cultures were placed 

 in the greenhouse on October 16 and harvested on March 18. Ten plants 

 were allowed to grow in each pot. The cool temperature in the green- 

 house did not permit rapid growth, and the plants were cut before ma- 

 turity was reached. The treatment and analytical results are given in 

 Table I. The cultures were weighed every other day, and the moisture 

 was maintained at 20 per cent. In removing the roots the soil was 

 shaken out of the pot and carefully loosened. The roots were then sepa- 

 rated out and washed. After drying they were weighed, and the non- 



