EXPERIMENT STATION KECORD. 723 



SOILS— FERTILIZERS. 



Amino acids and acid amids as sources of ammonia in soils, S. L. Jodidi 

 ET AL. (loiva Sta. Research Bui. 9, pp. 327-362). — In investigations previously 

 reported (E. S. R., 26, p. 615) tlie author reached the conclusion that "decom- 

 position of protein bodies contained in soil organic matter can be accomplished 

 through bacterial activity, the agency of enzyms, or even by purely chemical 

 means; . . . that it would be most natural to assume that the disintegration of 

 proteins in the soil is primarily protein hydrolysis, that is to say, that the pro- 

 teins present in the soil are gradually broken up to albumoses, peptones, acid 

 amids, and amino acids. The latter are the organic nitrogenous compounds out 

 of which ammonia is formed in order to be oxidized further to nitrites and 

 nitrates. The cycle of the nitrogen in the soil is, then, the reverse of what it is 

 in the plants. . . . 



" Inasmuch as . . . the bulk of the acid-soluble nitrogen in the soil is made 

 up of acid amids and amino acids, which are the organic substances immedi- 

 ately preceding the ammonia production, it is at once evident that direct ex- 

 periments having as their object to throw light upon the behavior of amino 

 acids in the soil are of considerable interest to agi'icultural science as well as 

 to practical agriculture." 



The production of ammonia by various amino acids and acid amids, includ- 

 ing glycocol, leuciu, phenylalanin, asparagin, aspartic acid, glutamic acid, 

 tyrosin, alanin, cadaverin, acetamid, and piopionamid, was studied by mixing the 

 substances with soil, allowing to stand at room temperature, and determining 

 the ammonia at the end of periods of from 2 to 10 days by distillation with 

 magnesium oxid or barium carbonate. 



The results were not conclusive, especially as to whether amino acids and 

 acid amids can be quantitatively deaminized in the soil. " It is possible that 

 while the ammonification of the amino acids and acid amids is still going on in 

 the soil, a portion of the ammonia produced is oxidized to nitrites and nitrates. 

 Loss of nitrogen through denitrification, as well as loss of ammonia escaping 

 from the soil, as gas, in case its ammonia-holding capacity is limited, is also not 

 out of the question. Bacteriological factors, as well as other conditions, will 

 also have to be taken into consideration. However, the data at hand permit of 

 drawing the following conclusions: 



"(1) The amino acids and acid amids examined readily undergo in the soil 

 the process of ammonihcation. (2) All other things being equal, the rate of 

 transformation of the amino acid and acid amid nitrogen into ammonia is 

 greatly influenced by their chemical structure so that amino acids and acid 

 amids of equal structure yield about the same proportion of ammonia and vice 

 versa." 



On the probable value to Bacillus coli of " slime " formation in soils, 

 C. Revis (Proc. Roy. Soc. [Londcm], Scr. B, 86 (J913), No. B 558. jrp- 371, 372) .— 

 Culture experiments with soil showed that " in all the flasks which contained 

 Bacillus coli, not only did the flasks retain their moisture for 3 years, but 

 during the first 12 months of the experiment had evidently taken up large 

 quantities of moisture from the atmosphere, and in one or two instances the 

 soil became completely water-logged. It seems evident that this extraordinary 

 behavior is connected with the B. coli and ... it seems reasonable to attribute 

 the water absorption of the soil to this curious property. These results pos- 

 sibly giv-e at the same time some explanation of the well-known power of many 

 organisms which occur in soil, especially the 'nodule' bacteria, to form 

 ' slime.' " 



20793°— 14^ 3 



