CHAPTER VIII 

 POTASH FERTILIZERS 



243. Potassium an Es- 

 sential Element of Plant 

 Food. Potassium is one 

 of the three elements 

 most essential as plant 

 food. In its absence 

 plants are unable to de- 

 velop. Oats seeded in 

 a sterile soil from which 

 potassium salts only were 

 withheld made the total 

 growth shown in the illus- 

 tration (Fig. 42). In dis- 

 cussing the content of 

 potassium compounds in 

 plants, soils, and food 

 stuffs, the term 'potash' 

 (potassium oxide, K 2 O) 

 is used. When present 

 in the soil in liberal 

 amounts and associated 

 with other essential ele- 



FiG. 4 2. Oat Plant grown without Potash. mentS, potash produces 



212 



