i88 



Bulletin 273. 



When nitrogen and phosphorus were appHed the increase in hay was 

 over c^^r greater than when potassium and phosphorus were added. 

 However, the residual effect of the potassium and phosphorus produced 

 a greater increase in corn than that of nitrogen and phosphorus. 



When all three of the elements were applied in ordinary amounts the 

 increase in hay was greater than when the phosphorus was doubled, 

 yet the larger amount of phosphorus produced a greater increase in corn, 

 showing again that the greater amount of sod was not the most effective 

 factor in increasing the yield of corn. It is also interesting to note that 

 when nitrogen was doubled, phosphorus doubled and potassium added, 

 the increase in hay was nearly 55^ greater than when the nitrogen 

 was not doubled ; yet the residual effects of these two combinations of 

 fertilizers were the same. Further, when the nitrogen was quadrupled 

 the increase in hay was greater than when it was only doubled, while 

 the residual effect was greater when the lesser amount of nitrogen was 

 applied. These comparisons show clearly that the increases in corn were 

 due in part at least to the residual effects of the fertilizers as well as 

 to the increased timothy sod on the treated plats. 



RELATIVE PRODUCTION OF EAR CORN AND STOVER 



There is no very definite relation between the nature of the fertilizer 

 added and the relation of ear corn to stover. In general, as the yield of 

 ear corn per acre increased, the yield of stover for every 100 pounds of 

 ear corn produced decreased. The following table will throw some light 

 on this. 



TABLE VI. 

 Showing Yield per Acre of Ear Corn and Weight of Stover Produced for 



Every 100 Pounds of Ear Corn. 



Treatment. 



Bushels 

 ear corn 

 per acre. 



Lbs. 



stover for 



100 lbs. 



ear corn. 



No fertilizer 



Nitrogen 



Phosphorus 



Potassium 



Nitrogen, phosphorus 



Nitrogen, potassium 



Phosphorus, potassium 



Nitrogen, phosphorus, potassium. 

 Nitrogen, phosphorus2, potassium. 

 Nitrogen2, phosphorus2, potassium 

 Nitrogen2, phosphorus, potassium. 

 Nitrogen4, phosphorus, potassium . 



Barnyard manure, lo tons 



Barnyard manure, 20 tons 



105. 1 



92.5 

 106.8 



78.5 

 89 -5 

 68.2 



69 -5 



73.8 

 77.8 



75-7 

 67.4 

 75-2 

 64.8 

 81.4 



