288 Fertilizers 



be all of one form, though the cost of the element will 

 naturally regulate this point to some extent. That is, a 

 part of the nitrogen should be nitrate or ammonia, and a 

 part organic; a part of the phosphoric acid should be 

 soluble (from superphosphates), and a part insoluble (from 

 ground bone, tankage or natural phosphates). The solu- 



FIG. 27. GARDEN FERTILIZER SOWER WITH HOE TO WORK 

 FERTILIZER INTO SURFACE SOIL. 



ble portions of both nitrogen and phosphoric acid con- 

 tribute to the immediate needs of the plant, and the less 

 soluble to its continuous and steady growth, and to the 

 potential fertility of the soil. 



The different kinds of vegetables. 



As previously stated, distinctions should be made in 

 reference to the kinds and amounts of plant-food applied 

 to the many different vegetables. It is impossible in a 

 discussion of this nature to give specific directions of the 

 details of fertilization of each vegetable; hence, the dis- 



