1906.] PUBLIC DOCUMENT — No. 33. 39 



A. — 77ie Relative Value of Nitrate of Soda, Sulfate of 

 Ammonia and Dried Blood as Sources of Nitrogen. 

 The three fertilizers under consideration have from the 

 first been applied in such amounts as to furnish nitrogen at 

 the rate of 60 pounds per acre to each plot. Each fertilizer 

 is always applied to the same plot. To furnish 60 pounds 

 of nitrogen, the application of the fertilizers at about the 

 following rates i)er acre is required : — 



Pounds. 



Nitrate of soda, ........ 375 



Sulfate of amuKniia, ....... 300 



Dried blood, 650 



Each of these fertilizers is used on two plots, on one of 

 which the source of the potash is the sulfate, on the other 

 the nuiriate, in both cases in such quantities as to furnish 

 equal actual potash. In addition to the nitrogen and potash 

 fertilizers, dissolved l)oneblack is applied at the rate of 320 

 pounds per acre to all plots. The amount of actual potash 

 applied is at the rate of 120 pounds per acre ; the amount 

 of actual phosphoric acid at the rate of 50.4 pounds per acre. 

 The source of the potash used affects the results on some of 

 the crops in a marked degree. This is especially the case 

 where sulfate of ammonia is the source of nitrogen. 



The results obtained previous to this year may be summa- 

 rized as follows : — 



For the early crops, i.e., the crops making most of their 

 growth before mid-summer, including onions, lettuce, table 

 beets, garden peas, spinach, early cabbages and strawberries, 

 the nitrate of soda has been found the most effective source of 

 nitrogen.' 



The relative standing of the different nitrogen fertilizers, 

 as measured by the total yields, including leaves, vines and 

 tops, as well as the marketable product, is as follows for the 

 early crops : — 



Per Cent. 



Nitrate of soda, 100.00 



Dried blood, 95.64 



Sulfate of ammonia, ...... 60.95 



' Sixteentli annual report, Hatch Experiment Station, p. 124. 



