IRISH POTATOES 249 



humus in the soil through the agency of legumes or the application of domes- 

 tic manures, so that the applied nitrogenous materials may be more fully 

 utilized. 



Bulletin 137 of the New York Agricultural Experiment Station says 

 that the experiments made at that Station furnish strong evidence that the po- 

 tato growers of Long Island are annually wasting large quantities of valu- 

 able fertilizing ingredients. Market gardening is there carried on in the most 

 intensive manner, and the fertility of the somewhat poor soil is supplemented 

 by the use of surprisingly large quantities of commercial fertilizers, an outlay 

 of $20 per acre for plant food of this character being not uncommon. Potato 

 growers frequently apply one ton of high grade superphosphate per acre, 

 while in the Station experiments the most profitable result each year was ob- 

 tained by the use of only half this quantity of fertilizer, and the residual or 

 second year effect was practically the same with the 1,000 pounds as with the 

 2,000 pounds. Heavier yields were obtained from the larger application, 

 but the additional gain from the use of more than 1,000 pounds of fertilizer 

 was at a greatly increased cost per bushel. We would note, however, that the 

 soils at Geneva and those on Long Island are very different in their physical 

 character, and the latter are far less retentive than the former. The plat on 

 which no fertilizer was applied made 113.1 bushels per acre. An application 

 of 500 pounds of fertilizer made an increase of 34.1 bushels of large potatoes, 

 1.000 pounds made an increase of 69.1 bushels of large potatoes; 1,500 pounds 

 made an increase of 77.5 bushels of large potatoes, and 2,000 pounds made 

 78.7 bushels increase. It was found that the fertilizer formula based on the 

 analysis of the potato, gave less results than the formula commonly used on 

 Long Island, which contains 4 per cent, nitrogen, 8 per cent, phosphoric acid 

 and 10 per cent, of potash in the form of a muriate. 



The following table is given, showing the influence on the crop of the 

 different fertilizers: 



The Long Island formula gave better results with each quantity of fertil- 

 izer and produced an average of nearly 23 bushels per acre more than did 



