22 



EXPERIMENT STATION. 



[Jan. 



The Comparison of Different Materials as a Source of 



Nitrogen. 



Field A. 

 In this experiment there are eleven plots of one-tenth acre 

 each, separated by division strips 4 feet in width. They have 

 been fertilized each year according to the following plan : ^ — 



The nitrogen, phosphoric acid and potash are applied in 

 equal amounts to all plots except 4, 7 and 9. These receive 

 phosphoric acid and potash but no nitrogen. 



Dnring the twenty-three years of the experiment the crops 

 grown have been: 1890, oats; 1891, rye; 1892, soy beans; 1893, 

 oats; 1894, soy beans; 1895, oats; 1890, soy beans; 1S9T, 

 oats; 1898, oats; 1899, clover; 1900, potatoes; 1901, soy beans; 

 1902, potatoes; 1903, soy beans; 1904, potatoes; 1905, oats 

 and peas; 1906, corn; 1907, clover; 1908, clover; 1909, clover; 



1 The materials are used at the following rates per acre: — 



Pounds. 



Nitrate of soda 290 



Sulfate of ammonia, .............. 225 



Dried Vjlood 525 



Muriate of potash, .............. "50 



Sulfate of potash 485 



Dissolved bone-black, 500 



Manure 8,000 



» In addition, nitrate of soda, dissolved bone-black and sulfate of potash-magnesia have been 

 applied to equalize the nitrogen, phosphoric acid and potash on plots 1-10. 



