CHAPTER XVIII 

 PURCHASING PLANT-FOOD 



Necessity of Purchase. The necessity of 

 buying plant-food in the form of commercial 

 fertilizers is a mooted question in any naturally 

 fertile agricultural region just so long as crop 

 yields do not drop to a serious extent. The nat- 

 ural strength of the land and the skill that enters 

 into the farming are important factors in deter- 

 mining the profitableness of recourse to purchased 

 plant-food. The free use of organic matter to 

 maintain the supply of humus defers the time 

 when commercial fertilizers should be used. Good 

 tillage frees the potential plant-food of the soil, 

 and delays the day of necessary purchase. The 

 farm so situated that it can have all its products 

 fed upon it is longer independent of outside help. 

 The profitable use of feeding-stuffs from other 

 farms is a safe way of escaping the direct purchase 

 of fertilizers, although it is a transfer of fertility to 

 the farm as surely as the employment of fertiliz- 



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