INSTITUTE, PUSA, FOR 1918-19 



43 



Another noticeable feature was the fact that in a few 

 isolated pots (about 6 per cent, of the total) a very abnormal 

 growth took place, varying from 200 to 500 per cent, 

 increase over the check pots in their particular series. 

 These abnormalities occurred in pots containing green 

 manure only, as well as in pots to which only ammonium 

 sulphate had been added, and as the analysis of the soil 

 gave no clue it is difficult to ascribe the result to any parti- 

 cular cause. I believe that other officers of the department 

 have had a similar experience. 



Eliminating these abnormal pots a fair comparison can 

 be drawn. The underlying object of the experiment was 

 to test the conclusion previously arrived at that green 

 manures in relation to paddy cultivation mainly act in an 

 indirect manner, and that their maximum effect would be 

 experienced when they are employed in conjunction with 

 direct manures. Nitrogen in the form of ammonium sul- 

 phate was taken as the variable mineral manure, and it was 

 added in such quantity that each series contained nitrogen 

 at the rate of 0, 20, 40, 80 and 160 lb. per acre as the case 

 might be. To half the pots green manure was added at the 

 uniform rate of 10,000 lb. per acre, so that a comparison of 

 the effect of this quantity used in conjunction with increas- 

 ing amounts of nitrogen could be determined. The average 

 results were as follows, the crop values being given in 

 grammes : — 



D 



