io6 



Journal of Agricultural Research 



Vol. XXII. No. a 



In this experiment sea sand was used which had been washed with 

 dilute hydrochloric acid and large volumes of distilled water. The sand 

 still contained sulphur compounds, but no sulphates soluble in dilute 

 hydrochloric acid. Six kgm. of sand were mixed with lo gm. of calcium 

 carbonate and placed in paraffined clay pots. Where elemental sulphur 

 was used, 0.75 gm. was added at the same time. The other nutrients 

 added were applied in solution form through a period of 70 days; the 

 growing period was 80 days. The total amount of sodium sulphate 

 which was added varied in the different cultures. Concentration i 

 denotes 1.55 gm., concentration 2, 3.10 gm., etc. The same figures apply 

 to calcium sulphate too. All cultures, with the exception of No. 3, 

 13, 20, and 21, received 3.9 gm. of sodium nitrate, and they each re- 

 ceived 0.75 gm. Every culture received 2.6 gm. of potassium dihy- 

 drogen phosphate and 1.3 gm. of magnesium chlorid. Twenty plants 

 grew in each pot, and the moisture content varied fron 15 to 20 per cent 

 in the different cultures. The weights recorded are the average of 

 duplicates, and the analyses were made on a sample obtained by mixing 

 the duplicates. The 22 cultures from 11 to 21, inclusive, were inocu- 

 lated with legume bacteria and 5 gm. of beaverdam soil added to the 

 same culture. 



Table III. — Analytical results of clover grown on sand receiving a nutrient solution 



Uninoculated series. 



Cul- 

 ture 

 No. 



Form of sulphur 

 added. 



Sul- 

 phate 

 con- 

 cen- 

 tra- 

 tion. 



Weight 

 of air- 

 dry 

 clover. 



Gm. 

 9.65 

 10. 7 



3-95 



8.7s 

 6.9 

 4- IS 

 6.62 

 7. 02 

 S-I 



Total 

 S. 



Per ct. 

 o. 26 

 .42 

 •30 

 •30 

 •34 



Total 



N. 



Per ct. 

 3-76 

 3-77 

 2. 00 

 3- 50 

 3-69 

 3-90 

 3-75 

 3-8s 

 3- 80 



Inoculated series. 



Cul- 

 ture 

 No. 



013 

 14 

 tS 

 j6 

 J7 

 18 

 19 

 a 20 

 a ji 



Weight 

 of air- 

 dry 

 clover. 



Gm. 



10. 00 

 7. 00 

 4.80 

 6.4s 

 6.8s 

 7-3 

 7- 77 

 7-3° 

 5.90 

 7-5° 

 S-07 



Total 

 S. 



Perct. 



o. 27 

 30 



Total 



N. 



Sul- 

 phate 

 S. 



Perct. 

 3.62 

 3-71 

 3.49 

 3- 70 

 3.60 

 3-90 

 3- 69 

 3- 70 

 3- 90 



2. 42 

 2.46 



. 12 

 .08 

 .18 



■ I."; 

 .08 

 • 17 

 .18 



.09 

 .14 



Or- 

 ganic 

 S. 



Perct 

 IS 



" Low nitrate. 



In the foregoing data the low sulphur contents occur in the clover 

 grown in the pots receiving less nitrate nitrogen. In the inoculated series 

 the sulphur content of the clover does not appear to increase by increasing 

 the sulphate sulphur of the nutrient media. On the other hand, where 

 there is a reduction in nitrate added, there is an appreciable reduction in 

 the sulphur content of the clover. In the other series, where the concen- 

 tration of legume organisms was not as great at the start, the percent- 

 ages of sulphur generally run higher. In No. 3 the percentage of 



