15 



RESULTS OF THE ADDITION OF POTASH. 



V;ihie of tlie net avenige increment, 

 Result, 



$2.44 

 .76 loss. 



RESULTS OF THE ADDITION TO NOTHING OF 



The results of this experiment are, on the whole, not veiT conclu- 

 sive as to the requirements of the soil. The evident difference in 

 natural fertility complicates matters. The fertilizers used on the 

 poorer side of the field evidently stood a better chance to make their 

 influence felt than those used on the other side. The average net 

 increase caused I)y each of the ingredients, nitrogen, jihosphoric acid 

 and potash is about equal; but it is noticeable that nitrogen causes a 

 smaller increase over nothing, than either of the otheis. It is impor- 

 tant to bear in mind, however, in this connection that the element 

 nitrogen was furnished by the amount of fertilizer used in a much 

 smaller proportion of the total taken by the crop than were the phos- 

 phoric acid and the potash. Thus Prof. Levi St(ickbridge, in the 



