CHAPTER XXI 



COMMERCIAL FERTILIZERS FOR VARIOUS CROPS 



FORMULAS for the making of fertilizing mixtures 

 for farm crops must in the nature of things be 

 merely suggestive, since soils vary so much in 

 their composition and needs, and crops also vary in their 

 manurial requirements. 



The student-farmer will study his soil or soils, for often 

 the soils are very different in the different fields of the 

 same farm. The chemist can give httle aid in this matter, 

 though he can find out what the composition of your soil 

 is, but cannot tell you anything in regard to the availabihty 

 to crops of the materials the soil contains. 



The American farmers are wasting a great deal of 

 money in the purchase of commercial fertihzers which 

 they could save by a more careful study of the needs of 

 their farms, and by using the legume crops for the getting 

 of nitrogen that costs so much in a complete fertihzer. 

 We believe that the day is rapidly approaching when the 

 American farmers will abandon for any of the usual farm 

 crops the purchase of complete fertihzers, or those con- 

 taining the three important ingredients, nitrogen, phos- 

 phoric acid, and potash, and will by short rotations get 

 through the legume crops all the nitrogen they need, aided 

 by the home-made manures made from the feeding of the 

 legume forage, and will devote themselves in an inteUigent 



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