PLATE 33 

 Sand cultures with potassium salts: 



A. — I, Turkey Red wheat. Potassium supplied in potassium nitrate. 



1, Control in culture solution containing no potassium. 



2, Control culture in complete Shive solution (R5C2). 



3, Culture solution, 88.6 pounds of potassium per acre. 



4, Culture solution, 433.2 pounds of potassium per acre. 



5, Culture solution, 866.4 pounds of potassium per acre. 



6, Culture solution, 1,772.8 pounds of potassium per acre. 



7, Culture solution, 2,659.3 pounds of potassium per acre. 



II, Red clover. Potassium supplied in potassium nitrate. Individual cul^ 

 tures as above indicated. 

 B. — I, Turkey Red wheat. Potassium supplied in potassium chlorid. Individual 

 cultures as above indicated. 

 II, Red clover. Potassium supplied in potassium chlorid. Individual cul- 

 tures as above indicated. 

 C. — I, Turkey Red wheat. Potassium supplied in potassium sulphate. 



II, Red clover. Potassium supplied in potassium sulphate. Individual 

 ctilttires as above indicated. 



