CHAPTER VI 

 MISCELLANEOUS FERTILIZING MATERIALS 



IN addition to the specific fertilizer materials described 

 in the previous chapters, which constitute the standard 

 sources of supply, a number of other products exist, and 

 should be considered here. Certain of these may serve 

 in the manufacture of fertilizers, and certain others, which 

 are not suitable for this purpose, may be used to advantage 

 either because they furnish the constituents in consider- 

 able quantities, or in other ways assist in improving the 

 fertility of the soil. They are often a cheap source of 

 nitrogen, phosphoric acid or potash, besides contributing 

 toward "condition" of soil, which exercises a decided in- 

 fluence in making possible the best use of commercial 

 fertilizers. 



Furthermore, while a consideration of these products 

 may not be regarded as strictly pertaining to the subject 

 of commercial fertilizers, a discussion of them is valuable, 

 in order that certain impressions now existing concerning 

 them may be corrected. These impressions, while not 

 entirely erroneous, are not wholly in accord with scientific 

 facts, particularly as to how far they may be substituted 

 for the better products ; and on this point information as 

 full and exact should be had as the limited knowledge that 

 we have of the subject will permit. These various products 

 cannot be strictly classified into the three main groups : 

 nitrogenous, phosphatic and potassic. They are, as a rule, 



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