24 BULLETIN" 158, 17. S. DEPARTMENT OF AGRICULTURE. 



estimated, and the extent of the hydrolysis of the original proteins 

 was determined. It was also shown by this method that the proteose- 

 like compound was composed of acid amide radicals, diamino acid 

 radicals, especially lysine, and monoamino acid radicals, particu- 

 larly the monoamino acids which contain non-amino nitrogen. 



The question of the availability of nitrogen is discussed and from 

 a consideration of the amount and the physiological action on plants 

 of the different forms of nitrogen present in the fertilizer it is con- 

 cluded that the water soluble nitrogen of this fertilizer should have 

 an availability equal to or greater than the nitrogen of dried blood, 

 or other high-grade fertilizers. These results are in accord with the 

 results obtained by the plant method of determining availability. 



The general chemical principle which underlies the method for 

 rendering available the nitrogen contained in most trade wastes, 

 which are to be used as fertilizing materials, is shown to be either 

 partial or complete hydrolysis of the protein of the wastes by any 

 suitable means. 



The more complete the hydrolysis the more available the nitrogen 

 in the fertilizer becomes, since the products of complete hydrolysis 

 of proteins are not only utilized by the plants themselves as nutrients 

 but they are more easily ammonified when placed in the soil than are 

 the more complex compounds, such as peptones, proteoses, and the 

 proteins themselves. 



This investigation aims only at an explanation and exposition of 

 the general chemical principles involved in the treatment of trade 

 wastes and other organic material to render the nitrogen contained 

 therein more available for agricultural purposes. It does not aim to 

 present the research methods here employed as general methods for 

 analyzing such fertilizers, nor can the quantitative figures obtained 

 be expected to apply to all products of similar manufacture, for the 

 reason that the different kinds of nitrogen compounds will necessa- 

 rily show different proportions according to the nature of the mate- 

 rials which enter into the mixture. 



ADDITIONAL COPIES 



OT THIS PUBLICATION MAT BE PROCURED FEOM 



THE SUPEBrNTENDENT OF DOCUMENTS 



GOVERNMENT PP.ESTHNG OFFICE 



"WASHINGTON, D. C. 



AT 



5 CENTS PER COPY 



WASHINGTON : GOVERNMENT PRINTING OFFICE ; 1914 



