THE NITROGEN OF PROCESSED FERTILIZERS. 21 



isolated from the base goods are actually available to plants as such 

 and have a beneficial action. Of the monoamino acids, other than 

 the two isolated from base goods, which have been studied in regard 

 to their action on plant growth, three have been found to be beneficial, 

 one doubtful, and one is reported as being harmful. 



The high-grade nitrogenous fertilizers, such as dried blood, are 

 considered to have a high availability owing to the fact that the 

 nitrogenous materials when placed in the soil quickly undergo the 

 process of ammouifi cation and nitrification, the nitrogen thus being 

 changed into a form which can be immediately used by the plant. 

 In fact, Lipman x has proposed a method for the determination of the 

 availability of the nitrogen of organic fertilizers, depending on the 

 amount of ammonia produced under certain conditions in a given 

 length of time. It is evident from the above consideration that such 

 a method does not tell the whole story, since in the decomposition of 

 protein materials like dried blood intermediate compounds are 

 formed which are undoubtedly in themselves beneficial to plant 

 growth. In order, therefore, to understand the complete action of 

 the nitrogenous materials in the base goods it is necessary to know 

 how the compounds contained in it are acted upon by ammonifying 

 bacteria. Jodidi 2 has shown that the amino acids, and acid amides 

 are quite readily ammonified when placed in the soil, the rate of 

 ammonia formation and the amount of ammonia formed depending 

 apparently upon the chemical structure of the particular compound 

 under consideration. In general, he found that the simpler the chem- 

 ical structure of the nitrogen compound the more quickly and readily 

 it was ammonified. In the light of these facts it appears that poly- 

 peptids, peptones, proteoses, and proteins would be ammonified still 

 more slowly than the amino acids since their structure is increasingly 

 more complex. 



, Hartwell and Pember 3 in their study on the availability of the 

 nitrogen of base goods, by means of plant tests found that it had 

 apparently as high an availability as dried blood; the water soluble 

 nitrogen having even a higher availability. From the nature and 

 amounts of the compounds present in the base goods this might be 

 predicted. In the case of the dried blood, the nitrogen is practically 

 all in the form of complex protein material which must be broken 

 down into simpler compounds by bacterial action, with the formation 

 of ammonia and other nitrogenous compounds, some or all of which 

 may be of physiological importance to plants. With the base goods 

 the case is a little different, the greater part of the nitrogen is at 

 once available for plant use, and at the same time these available 

 compounds may be changed more easily and quickly by the bacteria 



i B .1. 246, New Jersey Expt. Sta., 1912. 



2 Research Bui. No. 9, Iowa Expt. Sta. 



3 Loc. cit. 



