24 



So far, Professor Wagner, whose injunctions do not savor of 

 uncertainty or hesitancy, and whose positive statements deserve 

 all the more credit, because they are made after a careful and 

 long-continued study of the nitrogen and phosphoric acid fertili- 

 zation. 



WHAT IS THE EFFECT OF SODA. 



It was during these researches that Prof. Wagner was led to 

 think that the potash (kali) salts possessed an effect upon plant- 

 growth, particularly nitrogen absorption, which had escaped 

 observation. It was Schultz-L<upitz who contended that not 

 only the potash (kali, K 2 O) of the kainit, but likewise the other 

 salts, exert a most favorable influence upon the crop. Concerning 

 this side- effect, as it were, Professor Wagner says that magnesia 

 and soda are there to be considered, the former of which is 

 recognized as a necessary element of plant-food, so that its 

 presence can, of c0urse, only be advantageous. As regards soda 

 (natron), however, it has been assigned so far only an indirect 

 influence. "This is an error," he says; "there is a direct 

 effect of it, and this direct effect of soda, that is to 

 say of soda entered into the plant, has proven during 

 my investigations of such importance that further researches 

 in that direction are of very great moment." 



In his opinion, "the decided preference expressed by Schultz- 

 Lupitz for kainit as potash (kali) salt is, like the better yield, 

 produced by the use of nitrate of soda as against sulphate of 

 ammonia, attributable to the eifect of the soda which kainit, as 

 well as nitrate of soda, contains, and which, heretofore, has not 

 been properly valued. ' ' 



OPINIONS OF PROMINENT GERMAN 



FARMERS ABOUT POTASH 



FERTILIZATION. 



What Schultz-Lupitz thinks about the potash (kali) question, 

 and its importance for agriculture, may be inferred from the fol- 

 lowing quotation from an address delivered before the Club of 

 the Landwirthe (farmers): " Section 4 of my resolution is to the 

 effect ' that the securing of the potash (kali) or kainit deposits 



