AND COLLEGE, PUSA, FOR 1014-15. 83 



probable that the discrepancies recorded between the ob- 

 servations of some workers npon the stimulating effect of 

 such salts upon nitrification may be explained by reference 

 to the fact that the cases in which contradictory results 

 were reported were not comparable owing to the use of 

 organic nitrogenous matter, from which toxins could have 

 arisen, in one series, and ammonium sulphate in another. 



An interesting case occurred in the field at Pusa in 

 which the use of copper sulphate as a precautionary 

 measure against attack by wire worms resulted in a large 

 increase on the treated plot as compared with an untreated 

 control although both were free from attack by wire worm. 



It was found in the case of seedling maize and joivar 

 grown in soil or sand and watered with extracts of soil 

 made toxic by keeping the latter under semi-anaerobic con- 

 ditions that the residual contents of the seed were attacked 

 by bacteria which had multiplied as a consequence of the 

 prevalence of such conditions and had been transferred with 

 the toxic extracts ; the result of this attack was the produc- 

 tion of toxic putrefactive bodies in immediate contact with 

 the seedling resulting in its death; this did not occur in 

 presence of copper sulphate. Mr. Milligan, Imperial Agri- 

 culturist, who drew my attention to the abovementioned 

 field result with copper sulphate, has pointed out the signi- 

 ficance of this observation in connection with this case, and 

 the importance of its bearing upon the vital question of 

 successfully bringing a field crop through the initial stages 

 of germination and growth especially in heavy soils. Ex- 

 periments are being carried out to test the value of anti- 

 septics in relation to the early stages of plant growth under 

 varying soil conditions from this point of view. 



The toxic action of nitrites upon growing plants was 

 demonstrated both under sterile and ordinary conditions 

 in water cultures. 



Nitrification. Numerous experiments on nitrification 

 in soils and solutions were carried out and much valuable 

 information on the subject obtained. This was especially 

 the case in connection with biological analysis of soils from 



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