AND COLLEGE, PUSA, FOR 1914-15. 79 



II. Training. 



Mr. Barkat Ali, Assistant to the Agricultural Chemist 

 to the Government of Punjab, who was under training in 

 this laboratory from 12th August 1912 to 13th August 1914, 

 during the latter part of his training carried out an in- 

 vestigation on the bacteriological aspects of " Reh " soils 

 from the Punjab and submitted a full and detailed report 

 on this subject referred to below. 



Mr. D. V. Bal, Assistant to the Agricultural Chemist, 

 Central Provinces, was under training from 20th August 

 1914. Mr. Bal applied the method of biological analysis 

 to samples of soils from Sind and carried out experiments 

 in connection with the investigation of the action of 

 bacteria upon nutrient matter in the soil and the occurrence 

 of toxins in soils. He also isolated Ps. campestris from a 

 specimen of diseased cabbage sent from Poona and from 

 others locally obtained. 



Mr. A. K. Bose, Assistant Chemist to the Indian Tea 

 Association, Calcutta, worked in this laboratory from 13th 

 February 1915. Mr. Bose was instructed in the method of 

 biological analysis of soils and carried out experiments 

 therewith on samples of soil from the Tea Districts as 

 referred to in this report. 



III. Soil Bacteriology. 



Bacterio-toxins in soils. The work on bacterio-toxins 

 in soils was continued and carried a stage further; it was 

 found that the inhibition of nitrification occurring in soils 

 under water-logged or semi-anaerobic conditions was not 

 due merely to lack of the oxygen required for formation of 

 the completely oxidized product, but to the action of toxins 

 resulting from the activity of certain classes of bacteria 

 which rapidly multiply under these conditions. That this 

 toxic action was not due either to ammonia or carbon 

 dioxide in excess was shown by the inhibitory action of 

 water extracts of the toxic soil upon nitrification in nor- 

 mally aerated soil, and more conclusively by that of certain 

 bacteria isolated from such soils, notably of one bacillus 



