1911. J PUBLIC DOCUMENT — No. 31. 47 



bushels. The average iiiereases due to the api)lieatioii of the 

 (.iift'erent fertilizers (used iu each case on four plots) were as 

 follows : — 



Bushels 

 per Acre. 



Nitrate of soda, 3.2 



Bone black, . . . . . . • • . • 6.8 



Potash, 28,3 



If wc represent the average increase in grain due to the ni- 

 trate at 100, that due to the bone black is 21-2, that due to the 

 jiotash 880.9. Similar figures for the stover are: — 



Pounds 

 per Acre. 



Nitrate, 186.2 



Bone black, 406.5 



Potash, 1,922.7 



IX. XoKTii AcKE Soil Test. 

 The soil test in this field was begun in 1890, and the crops 

 grown since that year in the order of succession have been as fol- 

 lows : potatoes, corn, soy beans, oats, grass and clover, grass and 

 clover, cabbages and turnips, potatoes, onions, onions, onions, 

 pi^tatoes, grass and clover, grass and clover, corn, soy beans, 

 grass and clover, grass and clover, grass and clover. The crop 

 the past year was soy beans, for which the potash appears to be 

 the dominant element. In this field one-half of each of the 

 plots, which are long and narrow, has received three applica- 

 tions of lime, respectively, in 1899, 1904 and 1907. On the 

 limed portion the increases due to the application of single fer- 

 tilizer materials for the muriate of potash alone was 10.22 

 bushels per acre; for the nitrate of soda alone, 0.12 bushels; for 

 the dissolved bone black alone, a loss of 4.45 bushels. The 

 umriate of potash in combination with the other fertilizer ele- 

 ments did not give as large an increase in the crop as when used 

 alone. The results will not be discussed in full at this time, 

 but I may add that they are such as to suggest that the soda of 

 the nitrate of soda is to a considerable extent either rendering 

 the natural potash compounds of the soil available, or is itself 

 to some extent taking the place of potash in the economy of the 

 plant. 



