88 PHOSPHATES AND BACTERIA 



It is difficult to explain why at one centre the numbers of bacteria 

 should show marked increases as the result of the application of 

 basic slag, whilst at another centre, where the effect of the basic 

 slag on the crop is quite as marked, the bacterial content does not 

 appear to have been appreciably affected by the application of basic 

 slag. It may be that the lack of effect at Martin's Hearne is due to 

 the sourness of the soil, but counts made on the portion of the basic 

 slag plot which had received a dressing of ground lime in April 1920 

 showed no appreciable advantage in this respect over that portion 

 of the plot which had not been so dressed. 



