CHAPTER III 

 NITROGENOUS FERTILIZERS 



NITROGEN is the most expensive constituent of fertilizers, 

 and, all things considered, it is one of the most useful. 

 Nitrogen exists in nature as a component of the air, and 

 though quite as necessary to vegetation as carbon or 

 oxygen, which also exist in the atmosphere, and which 

 are readily acquired by all plants, all plants do not 

 have the power of acquiring nitrogen from this source. 

 This power seems to be limited to a class of plants called 

 Leguminosse, to which belong the various clovers, peas, 

 beans, vetches and a number of others. The important 

 farm crops belonging to the other botanical groups of plants 

 obtain their nitrogen largely, if not altogether, from the soil. 



Vegetable or animal matter containing nitrogen may 

 serve as a source of nitrogen to plants, though it cannot 

 feed them with this element to any extent until it decays 

 or rots. In order to obtain a clear conception of the use 

 of nitrogen as a fertilizer, one should understand the need 

 of plants for it, what is meant by form of nitrogen, and the 

 sources from which the various forms may be derived, 

 as well as the relative agricultural or crop-producing value 

 of the nitrogen in existing commercial forms. 



WHAT IS MEANT BY FORM OF NITROGEN? 



Strictly speaking, form of nitrogen has reference to its 

 combination or association with other chemical elements, 

 though sometimes the term " form " is used to indicate rate 



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