90 REPORT OF THE AGRICULTURAL RESEARCH INSTITUTE 



methods of effecting this, so far as I know, in India are 

 merely wholesale imitations of European practice, it is not 

 to be expected that total disregard of the very large differ- 

 ences in the conditions under which growth of the yeast 

 takes place in such widely different climates, will lead to 

 any high standard of efficiency. On the other hand, it does 

 not appear probable that any great experience or technical 

 knowledge should be required to make successful modi- 

 fications and adaptations of European methods to Indian 

 conditions, but some, at least, is essential. 



Saltpetre. Experimental work was carried on during 

 the year in order to obtain some knowledge of the biological 

 factors involved in the production of saltpetre in the soils 

 of Bihar. Information was sought for on the following 

 points : — 



(1) Why does this industry flourish in particular 



localities? 



(2) Could it be extended either in the places where it 



is already established or into other districts? 



(3) Could the methods of recovering the nitrate from 



the soil be made more efficient? 



The enquiry is still in an early stage, but it seems clear 

 that the leading factors in determining the localities in 

 which this industry can flourish are (1) a high percentage 

 of lime in the soil, (2) suitable climatic conditions for (a) 

 nitrification of organic matter, (b) accumulation of the 

 nitrates formed. 



These conditions are fulfilled in several districts 

 throughout India including the Punjab and the United 

 Provinces but it is in Bengal and especially in Bihar that 

 they are most favourable. It has been ascertained that 

 nitrification goes on during the monsoon in soils containing 

 much nitrogenous organic matter such as occurs in the 

 neighbourhood of villages, and that concentration of the 

 nitrates formed is prevented by the rainfall which carries 

 them down, and allows production to go on in the soil 

 stratum in which conditions of food supply and aeration 



