30 EXPERIMENT STATION. [Jan. 



different uitrogen-containiug materials which have been used. 

 On this basis, increase in crop, rather than on the basis of 

 total product, the manure and fertilizers used as a source 

 of nitrogen rank to date for the entire period of the experi- 

 ment, 1890 to 1906, inclusive, as follows: — 



Relative Increases in Yields (^Averages for the Seventeen Years') . 



Per Cent. 



Nitrate of soda, 100.00 



Barnyard manure, ....... 85.32 



Dried blood, 70.03 



Sulfate of ammonia, ...... 63.51 



It will be noticed that, Avhatever the basis of comparison, 

 the nitrate of soda has on the average given results consid- 

 erably superior to those obtained either with manure or with 

 either of the other nitrogen fertilizers. It will also be no- 

 ticed that the sulfate of ammonia, on the other hand, has 

 given results much inferior to those obtained with either of 

 the other materials supplying nitrogen. If nitrogen, then, 

 can be purchased in the form of nitrate at a price j)er unit 

 not exceeding that which it will cost in other forms, there 

 can be little doubt that it should be depended upon as a 

 source of this element for most of the crops of the farm. 

 The results of the past season, however, indicate that, as 

 would naturally be anticipated, the nitrate does not show the 

 same degree of superiority for corn as has usually been shown 

 with the crops raised in this field, almost all of which com- 

 plete their growth at a much earlier date in the season than 

 corn. 



II. — The Relative Value of Muriate and High-geade 

 Sulfate of Potash. (Field B.) 

 In this experiment, muriate of potash is compared with 

 the high-gi-ade sulfate on the basis of such applications as 

 will furnish equal actual potash per acre. These potash salts 

 are used in connection with bone meal at the rate of 600 

 pounds per acre. The experiment was begiui in 1892. Dur- 

 ing the first eight or nine years, potash salts were applied 

 in varying quantities, but for the most part at the rate of 

 about 350 to 400 pounds per acre. Since 1900, each has 



