1900.] 



PUBLIC DOCUMENT — No. 33. 



35 



1. The various materials furnishing nitrogen rank in the 

 following order: manure, dried blood, nitrate of soda and 

 sulfate of ammonia. 



2. The plots receiving no nitrogen approach in average 

 yield much more closely to those getting this element than has 

 been the case with any previous crop on this land. This must 

 be regarded as highly significant, for it ivill be remembered 

 that this field has been under experiment for eleven years, and 

 in all that time these plots have received no nitrogenous ma- 

 nure or fertilizer of any kind. The clover must, it seems 

 evident, have drawn from the air for this element, in which, 

 as is well known, it is especially rich. 



Fertilizers for Garden Crops. (Field C.) 

 This series of experiments was begun in 1891, and has 

 for its objects to test the relative value for garden crops : 

 (1) of sulfate of ammonia, nitrate of soda and dried blood 

 as sources of nitrogen; and (2) of muriate and sulfate as 

 sources of potash. For full details concerning the methods 

 followed and earlier results, reference is made to my eleventh 

 annual report. It should, however, be pointed out here 

 that partially rotted stable manure has been applied in equal 

 amounts to all the plots for the last two years. The amount 

 of such manure used this year was 7,200 pounds per plot. 

 The fertilizers used were as follows : — 



Annual Supply of Manurial Substances (Pounds). 



C Sulfate of ammonia, 38 



Plot 1 J ]\Iuriate of potash, 30 



(^Dissolved bone-black, 40 



C Nitrate of soda, 47 



Plot 2,^ Muriate of potash, 30 



(^Dissolved bone-black, 40 



(Dried blood, 75 



Plot 3,^ Muriate of potash, 30 



(.Dissolved bone-black, 40 



C Sulfate of ammonia, 38 



Plot 4,^ Sulfate of potash, 30 



(Dissolved bone-black, 40 



C Nitrate of soda, 47 



Plot 5, ^ Sulfate of potash, 30 



(^Dissolved bone-black, 40 



( Dried blood, 75 



•Plot 6,^ Sulfate of potash, 30 



(_ Dissolved bone-black, 40 



