6o4 



Journal of Agricultural Research voi.xv.Ncii 



4 per cent of water. The treatment of the soil otherwise was essentially 

 the same. After the reagents had acted for three days, the unevaporated 

 samples were made up to one-half saturation. Those from which the 

 reagents were evaporated were left open for two days and then made 

 up to the same degree of saturation. All were cotton-plugged and 

 incubated at room temperature. The water lost through evaporation 

 was replaced from time to time. 



Table I. — Effect of carbon disulphid and toluol upon nitrogen fixation and nitrate 



accumulation 



CHEMICALS NOT EVAPORATED 



Treatment. 



Control, o cc 



Toluol: 



o. oi cc 



o. 05 cc 



o. 10 cc 



o. 25 cc 



0. 50 cc 



1. 00 cc 



5. CO cc 



Control, o cc 



Carbon disulphid: 



o. 01 cc 



o. 05 cc 



o. 10 cc 



o. 25 cc 



0. 50 cc 



1. 00 cc 



5. 00 cc 



Analyzed after four weeks. 



Azoto- 

 bacter 

 film. 



Typical 



..do.. 

 ..do.. 

 ...do.. 

 None. 

 ..do.. 

 ..do.. 

 ...do.-. 

 Typical 



...do.. 

 ...do.. 

 None.. 

 ...do.. 

 ..do.. 

 ...do.. 

 ...do.. 



Nitro- 

 gen 

 fixed." 



Mgin. 



10. 40 



11.80 

 12. 40 



11-75 

 7-05 



IO-55 

 7-o^ 



7-75 

 12.45 



12.05 



11. 90 

 425 

 4-45 

 3-45 

 2- IS 

 3-15 



NO3& 



Mgin. 



II- 3 



ir-3 



12.8 



12.8 



12. 8 



13-8 



3-2 



2. 2 



3-3 



Analyzed after six months. 



Azoto- 

 bacter 

 film. 



Typical. 



...do.... 

 ...do.... 

 ...do.... 



None. ... 

 ...do.... 

 ...do.... 

 ...do.... 



Typical. 



...do.... 



(?) 



None 



...do.... 

 ...do.... 

 ...do.... 

 ...do.... 



Nitro- 

 gen 

 fixed.o 



Mom. 

 9. 12 



9.70 

 9. 01 

 9.07 

 4-32 

 3-40 

 4. 61 



5-27 

 9. 12 



9. 18 



7-45 

 5-32 

 3- 13 

 0-5S 

 o. 65 

 6.68 



NO3& 



Mgin. 

 18.5 



18.5 



18. 5 



18.5 



20. o 



3-5 



3-5 



3-3 



18.5 



18. 5 



18.5 

 20. o 



4- I 

 3-5 

 3-3 

 3-2 



NH3 6 nitrogen. 



Trace. 



Do. 



Do. 



Do. 



Do. 

 Abundant. 



Do. 



Do. 

 Trace. 



Do. 

 Do. 

 Do. 

 Abundant. 

 Do. 

 Do. 

 Do. 



CHEMICALS EVAPORATED 



Control o cc 



Toluol: 



o. 01 cc 



o. 05 cc 



o. 10 cc 



o. 25 cc 



0. 50 cc 



1. 00 cc 



5. CO cc 



Control occ 



Carbon disulphid: 



o. 01 cc. 

 o. 05 cc. 

 o. 10 cc. 

 o. 25 cc. 



0. 50 cc. 



1. 00 cc. 

 5. 00 cc. 



Typical. 



...do.. 

 ...do.. 

 ...do.. 

 None . . 

 ...do.. 

 ...do.. 

 ...do.. 

 Typical 



...do.. 

 ...do.. 

 None . . 

 ...do.. 

 ...do.. 

 ...do.. 

 ...do.. 



9-45 



9. 20 

 8.67 

 10- 75 

 4-05 

 5. 20 



5-05 



4-45 



10. 00 



10. 10 

 9-35 

 4-45 

 3-35 

 3-30 

 3- 15 

 2.80 



12. o 



12. o 



10. 9 



12. o 



3-6 



3-6 



3-5 

 12. o 



12. o 



Typical . 



..do.... 



..do.... 

 ...do.... 



None 



...do.... 

 ...do.... 

 ...do.... 



Typical. 



...do.. 



(?) 

 None. 

 ...do., 

 ...do. 

 ...do. 

 ...do. 



9. i» 

 10. 28 

 62 



9-73 

 6.87 

 4. 12 

 3-35 



2. 74 

 3- 24 



21.8 



21.8 

 21.8 

 20. o 

 24. o 

 12. o 



21.8 



6-7 

 19. 2 



24. o 



21.8 

 21.8 



6.3 



5-8 



4.8 



12. o 



Trace. 



Do. 



Do. 



Do. 



Do. 

 Abundant. 

 Trace. 

 Abundant. 

 Trace. 



Do. 

 Do. 

 Do. 

 Abundant. 

 Do. 

 Do. 

 Do. 



a Nitrogen fixed in milligrams per 50 cc. of culture. b Nitrate in milligrams per 100 gm. of soil. 



