226 Report on Crop Production of the 



4 ^ 



Table XI shows the relation between the quantity of plant 

 food needed for the increase of crop and that applied in the 

 fertilizers. 



Table XI. — Feetilizer Elements in Fertilizers and in Crop Increase 



Pbodxjced. 



These figures make it very evident that, with the exception 

 of the nitrogen, the fertilizers in quantities of 1,000 lbs. or over 

 furnished the three important ingredients in great excess over 

 what the crops used, and in much greater excess, nitrogen 

 included, over the needs of the crops above what the soil could 

 supply. Such facts as these force us to the conclusion that crop 

 production is largely dependent upon factors other than the 

 mere supply of plant food. If, therefore, Long Island farmers, 

 or any others, for that matter, are to apply commercial fertilizers 

 in such generous amounts, they must give careful attention to 

 other soil conditions, such as water and humus supply if they 

 are to reap adequate returns. 



THE KIND OF FERTILIZER. 



The favorite fertilizer formula with Long Island farmers for 

 potato growing has for some years been nitrogen 4 per ct., phos- 

 phoric acid 8 per ct., and potash 10 per ct. The formula more 

 nearly conforming to the proportions of the three ingredients in 

 the potato crop is nitrogen 7 per ct., phosphoric acid 3 per ct., 

 and potash 10 per ct. Table XII shows the results of an experi- 

 mental com^parison of these two formulas for four years. 



The Long Island formula appears to have been uniformly 

 more efficient than the potato formula. As the former contained 

 as much potash as the latter, and. more nitrogen, its superiority 



