20 The Bulletin 



Effect of I^itkogen, Phosphoric Acid, Potash, and Lime Alone and 

 IN Combination With Each Other on Corn Yields. 



The experiments, tlie results of which are presented in Table 1, were 

 planned to show the effect on the yield of corn of different fertilizer ap- 

 plications, when two of the constituents were applied together, as nitro- 

 gen and phosphoric acid (NP) nitrogen and potash (NK), and phos- 

 phoric acid and potash (P K), and when all three of these fertilizer 

 constituents were applied to make a complete fertilizer (N P K) ; also 

 to test the effect of lime (L) when used alone and when used in connec- 

 tion with a complete fertilizer (N P K L). 



The results are shown as follows : yields of bushels of shelled corn and 

 pounds of stover per acre for the several years ; average yields, average 

 increases over the unfertilized (O) plats (this represents the effect of the 

 fertilizer applications), the value of the increase, the cost of the ferti- 

 liser, and the value of the increased yield of corn and stover and of 

 corn alone over cost of fertilizer. The value of the increased yield of 

 corn and stover and of corn alone represent the profit from the several 

 fertilizer applications after paying for the fertilizer itself. 



In these experiments the corn was cut, shocked and shredded, the 

 stover being all of the plant except the corn on the cob. 



Nitrogen and Phosphoric Acid, IST P (Plats 11, 10^, and 10). 



Nitrogen and phosphoric acid increased the yields over the unferti- 

 lized plats four out of the seven years, and the average yield on each of 

 the three fields was an increase. The average annual increase for the 

 two years on "Old Field" was 5.7 bushels of corn per acre; for three, 

 years on Field A, 2.2 bushels of corn per acre; and for two years on 

 Field B 3.9 bushels, or an average annual increase for the seven years 

 in the three fields of 3.6 bushels, worth 61 cents less than the cost of 

 fertilizer for corn alone, which is 60 cents gain for the increased yield 

 of corn and stover. 



Nitrogen and Potash, N K (Plats 12, 8 and 8). 



The application of nitrogen and potash combined gave a small in- 

 crease on Fields A and B while on "Old Field" the average yield was 

 the same as with no fertilizer. The average increase for the seven years 

 for all three fields was 2.1 bushels per acre. Considering the grain alone 

 this mixture was applied at an annual loss of 84 cents, but when the 

 value of the increase of stover is taken into account, there is a profit of 

 23 cents. 



Phosphoric Acid and Potash, P K (Plats 13, 9 and 9). 



Phosphoric acid and potash combined shows a decrease in corn on 

 all three fields, the average annual decrease on "Old Field" for two years 

 being 0.5 bushels per acre; for three years on Field A 1.7 bushels; and 

 for two years on Field B 0.2 bushels or an average of 0.9 bushels for 

 the three. On the basis of corn alone this mixture was applied at 



