PHOSPHORUS 119 



tion will cause further reactions to take place which grad- 

 ually render the phosphorus available. 



(6) Ground phosphate rock can be used to advantage 

 in a rotation which assures an abundant supply of decay- 

 ing organic matter. Decaying organic matter is the key 

 to profitable farming; few farmers realize when their soil 

 has an abundance of this material. It is the general opinion 

 that merely following a rotation will assure an abundance 

 of organic matter; as a matter of fact, it is necessary that 

 large crops be grown so that the crop residues will be large. 



