148 



CHEMISTRY OF FARM PRACTICE 



TABLE XIII. INFLUENCE OF POTASH ON GRASS LANDS. 



(HALL) 



of the sugar contained in sugar beets. Sulphate of potash, 

 double sulphate of potassium and magnesium, or potassium- 

 magnesium carbonate should be used for the crops named. 

 Truckers observe that when potatoes are fertilized with 

 potassium sulphate, they are smoother than when fertilized 

 with a salt of potash carrying chlorine. It has been shown 

 at the South Carolina Experiment Station that the water 

 content of sweet potatoes is higher when fertilized with 

 muriate of potash than when fertilized with sulphate of 

 potash. 



Double sulphate of potassium and magnesium is not ex- 

 tensively used in the United States. It contains about 

 26 per cent of potash, and may be used as a substitute for 

 sulphate of potash. 



Double manure salts contain from 20 to 30 per cent of 

 potash. It is used to some extent in the United States. 

 The potash is mainly in the form of a chloride, and sells, 

 usually, for more than does an equal amount of potash in 

 kainit or in muriate of potash. 



Potassium-magnesium carbonate is a dry, white material 

 containing from 20 to 25 per cent of potash combined as a 

 carbonate. It is highly prized by growers of tobacco and 



