200 



DR. DAUBENY ON THE ROTATION OF CROPS, ETC. 



8. Papaver somniferum. 



Poppies, although considered an exhausting crop, are said to be frequently grown 

 for years in succession without any apparent decrease, but the results of my experi- 

 ments serve to show, that this will not happen unless they are occasionally manured. 

 It is remarkable how near in this instance the average of the shifting and permanent 

 crops approaches each other. 



The following Table shows the results : — 



The annexed diagram shows the variations in the yearly produce 



