904 



Journal of Agricultural Research 



Vol. VI, No. 23 



there occurred any very hard frost; consequently these numbers do not 

 in any case represent the numbers found in frozen soil, which would 

 probably be higher than any of the results herein reported. 



e,ooqooor 



e ,000,000 



s, 000,0 00 



4,000,000 



/s 20 25 so 



/MCHES OF W/iTEf? ^PPUEO 



Fig. 3. — Curves of the number of colonies of bacteria developing from fallow soil with varying quantities 



of manure and water. 



The results obtained for May show the unmanured soil to have few bac- 

 teria present, while the number in the manured soil increases as the quan- 

 tity of manure increases. The water apparently had no marked effect 

 upon their activity; or if it had, it had been obliterated during the winter 



