610 Report of the Department op Field Crops op the 



It is interesting to note the relative yields from these two 

 mixtures, the essential differences between which is that the 

 former contains much more nitrogen and much less phosphoric 

 acid than the latter, the potash being the same. 



Table V. — Eelative Yield from Potato Formula and Long Island 

 Formula. 



AMOUNT 



of fertilizer 

 per acre 



None 



500 pounds. 

 1,000 pounds. 

 1,500 pounds. 

 2,000 pounds. 



Average ... 



AVKRAQK OP THRKB ExPEillMKNTS. 



Potato 

 formula. 



Long 



Island 



formula. 



84.8 



123.8 



Excess 



from Long 



Island 



formula. 



26. 

 17.8 

 14.1 

 14.4 



18.1 



AVKRAGK OF FlKET AND HalLOCK. 



Potato 

 formula. 



Long 



Island 



fornfula. 



113.1 



125.5 

 166.2 

 166.8 

 178.4 



159.2 



163.8 

 184.7 

 189.5 

 190.4 



182.1 



Excess 

 from Long 



Island 

 formula. 



38.3 



18.5 

 22.7 

 12. 



22.9 



The foregoing table of averages shows that there was a uni- 

 foipm and material difference in favor of the Long Island formula. 

 As before noted the vines were reported as one-fourth larger from 

 this mixture than from the other. The excess of crop from the 

 Long Island formula seems to be greatest where the smallest 

 amounts of fertilizer were applied, which may indicate either that 

 the small application of the " potato " formula did not furnish 

 the profltable maximum of phosphoric acid or that the large 

 applications contained an undesirable quantity of nitrogen com- 

 pounds. In either case, if future experiments substantiate the 

 results for 1897, the claim that the composition of a crop should 

 be the guide for mixing special fertilizers will be discredited. 



The Financial Side of the Experiments. 

 The potatoes from these experimental fields were sold at 75 

 cents per bushel for large (merchantable) and 25 cents for small, 

 and the money values found in the following table are calculated 

 from these prices. 



