l6 HOW TO MAKE SCHOOL GARDENS 



the forms in which nitrogen is most often 

 used. It should be applied in the pro- 

 portion of 150 to 300 pounds per acre. 



Potash, among other effects, stimulates 

 the production of plump seed and fruit 

 and intensifies the color of the bloom. 

 A deficiency of potash is shown by a lack 

 of fruit and small, often immature, seeds. 

 It is best supplied as sulfate and muriate 

 of potash and xmleached wood-ashes. 

 The latter often has a chemical effect on 

 heavy land to some degree the same as 

 Hme. Sulfate and muriate of potash 

 are applied 200 to 400 pounds to the 

 acre; wood-ashes, 500 to 1,500 pounds 

 to the acre. 



Phosphoric acid aids in developing 

 plump seeds. It is applied in bone com- 

 pounds and fossil phosphates, as South 

 Carolina and Florida rock. The applica- 

 tion is from 200 to 400 pounds* of treated 

 rock per acre. Many fertilizer dealers 

 make what they call complete fertilizers 

 by mixing the three required elements. 



* Made available with sulfuric acid. 



