140 



CORN CROPS 



Arbitrary mixture 

 Ratio . . 



Natural proportion .... 



Ratio ... 

 Elements required for 40 

 bushels corn 



Ratio . . . 



NrrEOQEN 

 Pounds 



24 

 _6 

 24 

 JB 



59 

 6 



Phosphobic 

 Acid 



PotTNDS 



24 



8 

 2^ 



21.2 

 2 



Potash 

 Pounds 



60 



12 

 15 

 j| 



34.0 

 3 



The arbitrary mixture had approximately three times 

 the phosphoric acid and potash in proportion to nitrogen 

 that the natural proportion showed. 



In this case the arbitrary mixture gave the best results, 

 as the crop was able to obtain nitrogen from the soil to 

 balance the fertilizer applied. The point is well illustrated 

 in a second experiment in which the fertilizer mixtures were 

 compared. The fertilizer was applied to corn in a three- 

 year rotation of clover, corn, and wheat. A part of the 

 benefit of the fertihzer went to the wheat and clover. 

 Results with all three crops are given on the following 

 page. 



Plot 19 received a smaller application of fertilizer at 

 less cost, yet it contained twice as much phosphorus, 

 which seems to be the one element that this soil most 

 required. 



The above table emphasizes that the corn grower should 

 handle nitrogen, phosphorus, and potassium more or less 

 independently, adjusting his fertihzer application to the 

 needs of the soil. The ready mixed fertilizer will not 

 ■usually be as profitable as the fertilizer mixed especially 

 for the case concerned. 



