The Bulletin 



27 



These results emphasize the importance of nitrogen for the produc- 

 tion of corn on this soil, but they likewise show that even on a soil 

 which responds so readily to this material little profit can be expected 

 from its use with corn. 



The average yield of corn during the seven years from the three 

 times normal treatment was 37.5 bushels of corn per acre. Not only 

 is this increase greater than is shown by any other application, but the 

 net profit after paying for the fertilizer is also greater. 



EFFECT OF VARYING QUANTITIES OF PHOSPHORIC ACID. 

 IN 1903 AND 1904. 



Number 



of 



Plat 







Yield of Stover in Pounds 

 Per Acre 



1903 



1904 



1909 



Ave. 



a° 



< 



•<5 u 



p^ 



<u - 



m O 



M 



a o 



bOd 



c3 3 



u +3 

 (D • o 



3.tS 3^ 



&ms 





•so 



Mca >-^ 

 a! oMh 



'" c3 OS'S 



go- 



« H tH m 

 3 CI O o 



> 



0] 



+3 4) Pi 

 «, Si O > <U 



Mc3^0:S 



> a H g^<u 



3 a o.S o 



52 



12 



62 



72 



2800 



3120 



2785 



2705 

 2758 



1921 



1969 



2104 



1810 

 1707 



2361 



2545 



5.1 



3.2 



2445 5.8 



2258 

 2233 



2.95 



128 



205 



212 



25 



$ 4.08 



3.06 



4.91 



2.17 



2.84 $ 1.24 $ 



3.36 



4.41 



5.46 



— .30 



.50 



-3.29 



.73 



-1.12 



— .35 



-3.40 



IN 1905, 1907 AND 1909. 



