CHAPTER X 



CHEMICAL ANALYSES OF FERTILIZERS 



A COMPLETE chemical analysis of a fertilizer shows 

 not only the total amount of the different constituents 

 contained in a brand, but the form in which they exist, 

 and in most cases, the source of the materials used is also 

 indicated. 



THE INTEKPRETATION OF AN ANALYSIS 



An analysis may show simply the total amount of 

 the constituents. This is not a sufficient guide as to 

 the value of a mixture, for while it is not possible to 

 indicate absolutely by analysis whether the organic 

 nitrogen, for example, is derived from blood (which is 

 one of the best forms), or from horn meal (one of the 

 poorer forms), it is possible to show whether the nitro- 

 gen is derived from nitrate or from ammonia, whether 

 the phosphoric acid is derived from a superphosphate 

 or a phosphate, and whether the potash present is in 

 the form of a sulfate or of a muriate. A high-grade 

 or a low-grade fertilizer, for example, may be distinctly 

 indicated by the analysis, since it is of a high-grade 

 if the three forms of nitrogen are present, if the total 

 phosphoric acid is chiefly soluble in water, and if the 

 potash has been derived from a sulfate or from a 

 muriate. On the other hand, if the analysis shows 



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