1909.] 



PUBLIC DOCUMENT — No. 31. 



33 



to present detailed reports of the different experiments in the 

 department of agriculture. As soon as opportunity and means 

 permit;, the different lines of investigation will be taken up 

 one by one and reported in full. Some of the more important 

 results of the experiments which have been carried on during 

 the past year may be briefly stated as follows : — 



I. The experiment on Field A, which has for its object to 

 determine the relative value, as sources of nitrogen, of barnyard 

 manure, nitrate of soda, sulfate of ammonia and dried blood, 

 has been continued. This experiment was begun in 1890. The 

 crop of this year was alsike clover, which, however, was con- 

 siderably mixed with grass that came into the different plots. 

 The nitrogen fertilizer giving the highest yield this year was 

 dried blood, closely followed by nitrate of soda. Representing 

 the yield of the latter by 100, the relative standing of the dif- 

 ferent materials used as sources of nitrogen, as compared with 

 the plots receiving no nitrogen, as indicated by the total yields, 

 were as follows : — 



The relative increase produced by the different nitrogen fer- 

 tilizers, as compared with the no-nitrogen plots for the nineteen 

 years during which the experiment has continued, is represented 

 by the following figures : — 



Per Cent. 



Nitrate of soda, ........ 100.00 



Barnyard manure, ....... 81.57 



Dried blood, 68.40 



Sulfate of ammonia, ....... 60.18 



These figures make it apparent that the nitrate of soda has 

 on the average given a much greater increase in crop than either 

 of the other materials used as a source of nitrogen. Since a 

 pound of nitrogen usually sells at a lower price in nitrate of 

 soda than in either of the others, the wisdom of making a 

 large use of this material as a source of nitrogen is apparent. 



