POTASH FERTILIZERS 21 7 



kept for a long time. Kainit is soluble in water 

 and can be used as a top dressing at the rate of 75 

 to 200 pounds or more per acre. 



250. Muriate of Potash. This is extensively used as 

 a fertilizer and is valuable for general garden and farm 

 crops. It is a manufactured product, potassium chlo- 

 ride, and ranges in purity from 60 to 95 per cent, 

 equivalent to from 35 to 60 per cent of potash, the 

 chief impurity being sodium chloride. The grade most 

 commonly found on the market contains about 50 

 per cent of actual potash, equivalent to 80 per cent 

 of muriate. Potassium chloride is readily soluble and 

 is a quick-acting fertilizer. When used in large 

 amounts, muriate of potash and other chlorides may un- 

 favorably affect the quality of some crops, as potatoes, 

 sugar beets, and tobacco. Ordinarily, muriate of pot- 

 ash is one of the cheapest and most active forms of 

 potash, and can be used as a top dressing at the rate 

 of 200 pounds or more per acre when preparing 

 soils for crops. It is valuable for grass and grain 

 crops, and has given good results on peaty lands. 92 



.251. Sulphate of Potash. --High-grade sulphate of 

 potash is prepared from some of the crude Stassfurt 

 salts and may contain as high as 97 per cent K 2 SO 4 , 

 equivalent to 50 per cent of potassium oxide (K 2 O). It 

 is one of the most concentrated forms of potash fer- 

 tilizer and is particularly valuable because it can be 



