POTASH FERTILIZERS 



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more potash than those from hard coal, but it is held in 

 such firm combination as to be of but little value. 



The ashes from sawmills where soft wood is burned, 

 and they are unprotected, are nearly worthless. When 

 peat bogs are burned over, large amounts of ashes are 

 produced. If the bogs were covered with timber, the 

 ashes are sometimes of sufficient value to warrant their 

 transportation and use. 



258. Commercial Value of Potash. - - The market value 

 of potash is governed by the selling price of high-grade 

 sulphate of potash and kainit. Ordinarily, it varies 

 from 4 to 5 cents per pound. As in the case of nitro- 

 gen and phosphoric acid, the market and field values, 

 as determined by crop yields, may be entirely at vari- 

 ance. Before potash salts are used, careful field tests 

 should be made to determine the actual condition of the 

 soil as to its need of potash. (See Chapter X, Commer- 

 cial Fertilizers.) 



