32 



The Bulletin. 



Table II— 



A%TEnAGE RESULTS FOR SEVEN 



Number 



of 



Plat. 



Fertilizer Application per Acre. 



(5!+ir-)- 

 (4+ll)-8 



122-10-9 



Unfertilized= 0= 



a 



a 

 te 

 o 





o o 



-c<; 



E o 

 o< 



13S.4 pounds 13% blood=-... ...2N= i 18 



150 pounds 14% acid phosphate= P=: i 



22.5 pounds 20% manure salt=: K= ' 



(52-142)- 



(4+ll)-8 Unfertili2ed= 0= 



13^-12-10 



21 



207.6 pounds 13% bIood= 3N= ' 27 



150 pounds 14% acid pho3phate= P= 



, 22.5 pounds 20% manure salt=-.- K= 1 



21 



O 



o 



(In 



4.5 



4.5 



Yield in Bushels 



of Sliolled Corn 



per Acre. 



1903 1901 1906 



Checks for plats 8, 9 and 10, Field A. and plats 102. i]2, 122 and I32. Field B, have been obtained from plat 

 natural fertility between check plats and a corrected check was figured on this basis for each treated plat 



THE EFFECT OF VARYING QUANTITIES OF NITROGEN. 



The experiments in Table II were planned to test the effect on 

 the yield of corn and stover of varying qnantities of nitrogen, leav- 

 ing the phosphoric acid and potash constant. 



On one ])]at the nitrogen Avas reduced to one-half the normal 

 quantity, making the application 44 pounds of nitrogen per acre, 

 or practically 1-i- per cent in the fertilizer mixture. On two of the 

 plats it was increased by two and three times the normal quantity 

 (t) pounds per acre), making the ajiplication 18 and 27 pounds per 

 acre respectively, or on the four plats 4^, 9, 18, and 27 pounds of 

 nitrogen per acre. 



The avei-age results for four years in Field B showed the largest 

 profit to have come from the application containing twice the normal 

 quantity of nitrogen per acre, or 18 pounds of nitrogen, the average 

 yield being 38.4 bushels corn per acre, and the proHt $10.70 over 

 cost of fertilizer on basis of corn alone or $10.37 on basis of corn 

 and stover. For two years in Field A the largest yields and profit 

 were from the application containing three times the normal 

 quantity of nitrogen, or 27 pounds nitrogen per acre, the average 

 yield of corn being 41.8 bushels i^er acre, and the profit $12.08 over 

 cost of fertilizer, on basis of corn alone, or $17.09 on basis of corn 



