6 The Bulletin 



$7.52 per acre, making the cost of fertilizer per bushel of increase in 

 corn 53 cents. 



5. The amount of potash in the normal fertilizer (300 pounds per 

 acre) used was 1% per cent, or 4^ pounds per acre. This amount 

 was varied so as to apply 2.2, 4%, 9, and 131^ pounds per acre, respect- 

 ively. On an average, the results show that the larger quantities were 

 not as profitable as the smaller amount, % per cent in the fertilizer 

 mixture. 



6. The amount of phosphoric acid in the normal fertilizer (300 

 pounds per acre) used was 7 per cent or 21 pounds of phosphoric acid 

 per acre. This quantity was varied so as to apply 10 V2, 21, 42, and 

 63 pounds respectively of phosphoric acid per acre. These amounts of 

 phosphoric acid would be supplied by 75, 150, 300, and 450 pounds 

 respectively of 14 per cent acid phosphate. The results show that the 

 largest yields on an average came from the use of 150 pounds of 14 per 

 cent acid phosphate, or 21 pounds of phosphoric acid per acre. None of 

 the applications, on an average, paid for the cost of fertilizer, but 150 

 pounds of acid phosphate with normal amounts of blood and manure 

 salt came nearest, the loss after paying for the fertilizers being 67 

 cents, when counting the corn and stover. Certain it is that for corn 

 on this soil in its present state 21 pounds of phosphoric acid per acre is 

 ample. 



7. Varying the amounts of the normal fertilizer mixture from 150 to 

 900 pounds per acre gave increased yields, but they proved unprofitable 

 for most of the applications. Profitable returns resulted from 450 to 

 600 pounds of fertilizer per acre. After paying for the fertilizer itself, 

 the following showing was obtained from different quantities of fertilizer : 



150 pounds of fertilizer per acre gave a loss for corn and stover of, 53 

 cents. 



300 pounds of fertilizer per acre gave a loss for corn and stover of 67 

 cents. 



450 pounds of fertilizer per acre gave a profit for com and stover of 

 88 cents. 



600 pounds of fertilizer per acre gave a profit for corn and stover of 

 $1.80. 



900 pounds of fertilizer per acre gave a loss for com and stover of 88 

 cents. 



8. In the comparison of dried blood and nitrate of soda as sources of 

 nitrogen, the total and increased yields over unfertilized plats were 

 fairly uniform and show on an average a slight advantage for blood 

 over nitrate of soda as a nitrogen furnishing material. The best re- 

 turns were secured by dividing the blood application, applying one-half 

 at planting with the carriers of phosphoric acid and potash and reserv- 

 ing the other half for application about July 1. 



9. When 300 pounds of fertilizer were (1) applied in the drill; 



