358 



BOARD OF AGRICULTURE. 



require, as a general rule, a much larger amount of potassa 

 than of phosphoric acid. A few figures bearing on this point 

 may serve here as an illustration. 



Phosphoric 

 Acid. 



Potassium 

 Oxide. 



Wheat (grain and straw), 



Indian corn, 



Meadow grasses, . 



Clover,. 



Potatoes, 



Turnips, 



Tobacco, 



Grapes, . . . 



Oats, .... 



Rye, ... 



Barley, .... 



Taking even the best economy for granted, there is scarcely 

 any reason to doubt that in very many instances an applica- 

 tion of soluble potash compounds as fertilizers will be as ben- 

 eficial as phosphatic fertilizers have proved to be. The main 

 point which the farmer has to consider, when contemplating 

 the use of the German potash salts, — on account of their 

 peculiar saline character, — consists in the question, what 

 particular hind of the above enumerated compounds would 

 be best, i. e., most efficient, in his case. As none of our for- 

 mer potash fertilizers — as wood-ash, nitre, etc. — can be 

 directly compared in regard to composition, and thus to 

 peculiar mode of action, with the German or Stassfurt potash 

 salts, it seems but prudent on our part to turn the experience 

 of others to account. Taking this view of the case, I present 

 subsequently, in a condensed form, the best indorsed experi- 

 mental results obtained in Germany, France and England. 



The sulphate of potash is unanimously indorsed as the 

 safest potash compound, — without regard to the kind of crop, 

 — and as far as the quality of some industrial products are 

 concerned. It increases the percentage of starch in potatoes 

 and of susrar in beets. It counteracts best, in common with 

 nitrate of potassa, the tendency of tobacco to char, and to 

 smell offensively, thereby rendering it better adapted to smok- 

 ing, and increasing its commercial value. Upon wet lands 



