New York Agricultural Experiment Station. 239 



reversed. With the pots receiving soda the proportion of potash 

 was but slightly higher than in the first series, but rather more 

 soda was present. The percentage of lime and magnesia seems 

 to increase with the decrease of potash and vice versa. 



Dr. Augustus Voelcker,^^ has conducted l\eld experiments with 

 crude German potash salts and common salt on mangolds. 

 Mangolds were grown upon a light sandy soil, the first series of 

 plats receiving no fertilizer, the next common salt and the third 

 crude potash salts, containing 24 per ct. Kg SO 4, 12 per ct. 

 MgSO^, 47.8 per ct. NaCl. 



In speaking of the yield the author says: — " Making due allow- 

 ance for the natural variation in the productive powers of dif- 

 ferent parts of the same field, common salt, it will be noticed in 

 every instance, gave as good results as an equal weight of the 

 more expensive crude potash salts. The larger dose of salt pro- 

 duced a greater increase than the smaller." 



"As the crude potash salts used contained twice as much 

 common salt as sulphate of potash, and common salt gave as 

 much increase as an equal weight of crude potash salts, it is 

 more than doubtful whether the potash in the latter had any 

 share in increasing the crop on the plats dressed with crude 

 potash salts." 



A study was made by Smets and Schrieber^^ of the potash 

 needs of various Belgian soils as well as the possibility, of the 

 replacement of part of the potash by soda. On some soils the 

 soda seemed to have no action; on others if the potash content 

 was not too small there was an increase of the crop. In the 

 presence of a larger quantity of potash the soda seemed to have 

 no action. 



Prof. S. W. Johnson^* in making what is undoubtedly a very 

 just review of the data bearing upon the use of potassium and 

 sodium by plants, places potassium as among the elements 

 absolutely essential to the life of agricultural plants. Concern- 

 ing sodium Prof. Johnson says: 



"Jowr. Royal Agr. Soc, 3: 86 (1867). 

 *'Biedermann's CentraWatt, 28: 227. (1898.) 

 "How Crops Grow. 



