Food for Plants. 153 



To draw conclusions from 1 to 2 years of such work 

 would be manifestly unfair, but when it is carried on 

 for a period of 10 or 20 years, seasonal differences, dif- 

 ferences due to the unequal decomposition of organic 

 matter and differences due to slight errors, which are 

 sure to creep in now and then, are largely smoothed out 

 and results are obtained which can be accepted with a 

 fair degree of confidence. The conlidence in such result 

 is strengthened when it is found that they check with 

 similar work conducted in other places or even in other 

 countries. 



The work was started in these cylinders in the spring 

 of 1898 wdth corn as the first crop in the rotation. Four 

 5-year rotations have been carried out as follows : 



First Rotation Third Rotation 



1898 Corn 1908 Corn 



1899 Oats (millet) 1909 Oats (com) 



1900 Oats (corn) 1910 Oats (corn) 



1901 Wheat 1911 Rye and oats 



1902 Timothy 1912 Timothy 



( t wo cuttings ) ( two cuttings ) 



Secoud Rotation " Fourth Rotation 



1903 Corn 1913 Corn 



1904 Oats (corn) 1914 Oats (corn) 



1905 Oats (comi 1915 Oats (corn) 



1906 Wheat 1916 Wheat 



1907 Timothy 1917 Timothy 



(two cuttings) (two cuttings) 



The corn following the oats is grown as a residual 

 crop (without further addition of fertijizers) to utilize 

 any nitrogen which the oat crop may have failed to get. 

 All corn is planted thick and harvested as forage rather 

 than as mature corn. Oats are harvested as oat-hay 

 just before maturity, and wheat is harvested at maturity 

 and saved as grain and straw. 



Nitrogenous materials are applied for each main crop 

 in the rotation as follows: 



Cylinder 4B, farm manure, at the rate of 16 tons per acre. 

 Cylinder 8 B. nitrate of soda, at the rate of 320 pounds per acre. 

 Cylinder 17B, ammonium sulfate, equivalent to 320 pounds of nitrate 



of soda per acre. p •. . n 



Cylinder 18B, dried blood, equivalent to 320 pounds of nitrate ot 



soda per acre. 



