POTASSIUM 125 



POTASSIUM 



128. Forms of Potassium Fertilizers. The chief ferti- 

 lizing materials carrying potassium are barnyard manure, 

 muriate of potash (KC1), sulfate of potash (K 2 S0 4 ), kainit 

 and wood-ashes. 



129. Kainit, Muriate of Potash and Sulfate of Potash. 

 Kainit is mined in Germany in the same way as rock-salt. 

 It was probably deposited in the same way. It was while 

 trying to get salt that kainit was found. It contains salt 

 and other minerals with about 12 per cent of potash (K 2 O). 

 Kainit is used as a fertilizer in Germany, but is not much 

 used in this country because it contains too many im- 

 purities on which to pay freight. 



Nearly all the potassium used in America is potassium 

 chlorid, or muriate of potash (KC1). This is manufac- 

 tured from the kainit. It contains about 50 per cent of 

 potash (K 2 O). It costs about $45 per ton, or about 4.5 

 cents per pound of potash. 



Sulfate of potash (K 2 SO 4 ) is also manufactured from 

 kainit. It costs about one cent per pound more for the 

 potash than in the form of muriate. It is used in cases 

 where the muriate is not desirable. The muriate usually 

 injures the quality of sugar beets and tobacco. 



130. Wood-Ashes. Hardwood-ashes contain 2 to 10 

 per cent of potash and average 5 to 6 per cent. They 

 also contain 1 to 2 per cent of phosphoric acid and about 

 34 per cent of lime (CaO). If the ashes are leached, most 

 of the potash is removed. Soft wood-ashes contain less 

 potash than those from hard wood. Coal-ashes contain 

 almost no plant-food. 



