CHAPTER XIII 

 POTASH AND SULFUR FERTILIZERS 



The materials used as potash fertilizers, with a very 

 few exceptions, are soluble in water. The matter of their 

 relative availability is, therefore, of minor importance. 

 When applied to soil, the potash salts are absorbed and held 

 in a condition in which they leach out only in moderate quan- 

 tities, but to a greater extent than does phosphoric acid. In 

 the absorbed condition, however, they are readily available 

 to plants. 



It seems strange that with the many thousand pounds of 

 potash contained in an acre of ordinary land, as may be/ 

 seen by consulting Table 17, there should be any benefit 

 derived from the few pounds of potash that are contained 

 in a fertilizer. The fact that the fertilizer is effective gives 

 emphasis to two facts : (1) the great insolubility of the 

 soil potash ; (2) the availability of the absorbed potash. 



231. Stassfurt salts. — Most of the potash fertilizers used 

 in the United States come from Germany, where there are 

 extensive beds varying from 50 to 150 feet in thickness, lying 

 under a region of country extending from the Harz mountains 

 to the Elbe river and known as the Stassfurt deposits. 



* There are two forms in which potash is found in the Stass- 

 furt beds. These are the sulfate of potash and the muriate 

 of potash. It is necessary to distinguish between these two 

 because the muriate, when used in large applications, has an 

 injurious effect on certain crops, among which are tobacco, 



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