lS6 Bulletin 2']'^. 



When the different fertiHzing materials were added singly, the potas- 

 sium has had by far the most marked effect on the following crop in the 

 production of forage, ear corn and stover. Nitrogen comes second in the 

 production of forage and ear corn, while there has beeen a decrease of 

 1.07 per cent, in the yield of stover. The phosphorus has not produced 

 a very marked increase, the greatest being that of 12.23 P^^ cent, increase 

 in ear corn. It is likely that one reason why the potassium plat has 

 produced an increase so much greater than that of either nitrogen or 

 phosphorus, is because of the previous growth of a large yield of alsike 

 clover following the application of the potassium fertilizer to the timothy. 

 The hay crop of 1907 which was harvested from this plat was more than 

 50^ alsike. clover. It would naturally be expected that the clover sod 

 when plowed under would be more effective in increasing the production 

 of corn than would that of the timothy. 



When the fertilizing materials were added in combination of two, 

 the resulting effect of phosphorus and potassium produced the greatest 

 increase of both forage and stover, while that of nitrogen and potassium 

 produced the greatest increase of ear corn, notwithstanding the fact 

 that this combination of fertilizers actually decreased the production of 

 stover i.oSy. The maximum increase in yield of forage, ear corn and 

 stover, due to artificial fertilizers, was obtained from the plats receiving 

 all three fertilizing materials. 



Doubling the amount of phosphorus from 320 to 640 pounds without 

 changing the amounts of nitrogen and potassium has increased the pro- 

 duction of forage, ear corn and stover approximately 7, 14.5 and 10.5^ 

 respectively, over that when these three materials were added in- single 

 amounts. Doubling the nitrogen increased slightly the production of 

 forage and decreased the production of stover. 



In previous years the highest yields of timothy hay due to artificial 

 fertilizers were obtained from plats receiving 320 pounds of acid phos- 

 phate, 80 pounds of muriate of potash and 320 pounds of nitrate of soda 

 per acre. The residual effect of this combination of fertilizers has also 

 produced the maximum increase in the yield of both forage and ear corn, 

 though not of stover. 



The applications of barnyard manure at the rate of 10 and 20 tons 

 per acre have increased the production of ear corn no and 115 per cent, 

 respectively. This is a much higher increase than was produced by any 

 form or combination of artificial fertilizers. The increase of forage and 

 stover due to the previous applications of the manure was not nearly 

 so great as was that of the ear corn. 



