CHAPTER VIII 



POTASH FERTILIZERS 



228. Potassium an Essential Element of Plant 

 Food. — Potassium is one of the three elements most 



essential as plant food. When it is 

 removed from a soil plants are un- 

 able to develop. Oats seeded in a 

 soil from which the potash only 

 had been extracted made the total 

 growth shown in the illustration 

 (Fig. 32). When potash is present 

 in the soil in liberal amounts vigf- 

 orous plants are produced. Potash, 

 like phosphoric acid and nitrogen, 

 is utilized by crops in the early 

 stages of growth. Potassium does 

 not accumulate in seeds to the same 

 extent as phosphoric acid and nitro- 

 gen, but is present mainly in steins 

 and leaves, consequently when 

 Fig. 32. Oat plant straw crops are utilized in pro- 

 grown without potash, during manure the potash is not 



lost or sold from the farm. But with ordinary grain 

 farming excessive losses of potash do occur, particu- 

 larly when the straw is burned and the ashes are wasted. 



