INSTITUTE, PUSA, FOR 1917-18 



57 



results and observations made in the plains of India and 

 elsewhere. The available evidence in favour of this view 

 was collected in 1914 and published in Pusa Bulletin 52 

 (Soil ventilation) in 1915. After this, further results 

 rapidly accumulated which were dealt with in 1916 in Pusa 

 Bulletin 61 ' (Soil aeration in agriculture). These two 

 papers were very favourably reviewed in a large number of 

 journals all over the world and many letters were received 

 from correspondents dealing with the obvious explanation 

 by the soil aeration factor of results hitherto obscure or but 

 little understood. The publication of these views was the 

 means of setting in motion a great deal of experimental 

 work both in India and other countries- The connection 

 between surface drainage, soil aeration and crop production 

 and the increase in yield which follows the slightest im- 

 provement in surface drainage were dealt with in 1915 in 

 Pusa Bulletin 53 (Soil erosion and surface drainage). 

 Recently, more information has been obtained on this ques- 

 tion which will be published when a convenient opportunity 

 occurs. 



During the past year, careful experiments have been 

 conducted both at Pusa and at Quetta on the effect on the 

 yield of the addition of inert materials such as potsherds 

 and sand. In all cases, increased yields have been obtained 

 both in the case of cereals and of leguminous crops. Some 

 of the Pusa results are given in Table III. 



Table III. 

 The effect of diluting Pusa soil with potsherds or sand. 



1. Wheat, oats and tobacco. 



E 



