84 REPORT OF THE AGRICULTURAL RESEARCH INSTITUTE 



various parts of the country, carried out for the most part 

 by Assistants of Provincial Agricultural Chemists under- 

 going training in this section. Mr. Barkat Ali, Assistant 

 to the Agricultural Chemist to the Government of Punjab, 

 made a valuable biological analysis of Reh Soils from that 

 province showing that although such bacterial activities 

 as are essential to nitrification are practically non-existent 

 in Reh Soils, this condition is completely altered by wash- 

 ing out the excess of salt. Mr. D. V. Bal, Assistant to the 

 Agricultural Chemist, Central Provinces, tested the nitri- 

 fying power and capacity of certain soils from Sind which 

 had undergone differential treatment in the field; this was 

 found to vary considerably as a consequence of treatment. 

 Interesting differences in comparative immunity shown by 

 the nitrifiers in these soils to the inhibitory effect of partial 

 anaerobic conditions ' as compared with the nitrifying 

 agents in Pusa soil were observed, nor was the addition of 

 lime beneficial in this respect. Nitrification in tea soils 

 from different districts was studied by Mr. A. K. Bose, 

 Assistant to the Scientific Officer to the Indian Tea Asso- 

 ciation; here very marked differences in nitrifying power 

 between different soils, were found with varying results 

 from the application of lime, and varying optima for 

 water. Further experience with the method of biolo- 

 gical analysis of soils has shown its value in elucidating 

 soil problems and has made it possible to reduce it to a 

 simple set of concurrent experiments. 



The observed influence of toxins upon nitrification has 

 been referred to above. 



Nitrate formation in field plots under different crops 

 has been under observation; grass has been found entirely 

 to prevent accumulation of nitrate in the soil in which it 

 is growing; this would have some bearing upon the action 

 of grasses upon fruit trees, as the absence of nitrates must 

 mean either that nitrification is inhibited or that the grasses 

 take up the nitrate as rapidly as it is formed, or that in 

 grassed-soil reduction takes place at least as rapidly as 

 oxidation. 



