AMMONIFICATION OF MANURE IN SOIL 



By H. J. Conn, Associate Bacteriologist, and J. W. Bright, Assisian: Bacteriologist, 

 New York State Agricultural Experiment Station 



FOREWORD 



A recent series of papers of the New York Agricultural Experiment 

 Station (8-iiy contained the results of a study of the microscopic flora 

 of the soil. The microorganisms of the soil were classified into a few 

 large groups, some of which were further subdivided, and in a few cases 

 the classification was carried as far as the recognition of species. This 

 preliminary work was considered necessary before studying the different 

 groups with the object of recognizing more of the individual species and 

 learning their functions. 



A complete study of all soil microorganisms would be an endless task, 

 and, indeed, rather unprofitable, provided the order of studying the 

 different types were left entirely to chance. To begin a study of this kind, 

 therefore, those organisms should be selected that are presumably impor- 

 tant. It is difficult to judge, a priori, the importance of any particular 

 microorganism in the soil, but a hint can be obtained by observing which 

 types predominate in natural soil under conditions of considerable 

 importance in practice. The organisms chosen for investigation in the 

 present work were found to multiply in freshly manured soil. In such 

 soil, ammonification and other forms of decomposition are vigorous and 

 there is good reason to believe that the most rapidly multiplying organisms 

 are of practical importance. Upon adding manure to soil several kinds 

 of bacteria have been found to multiply strikingly, but many of them are 

 difficult to recognize and especially difficult to describe so that others may 

 recognize them. It has seemed unvvise to make a detailed study of any 

 organism which could not be recognized by other workers; and the 

 work has therefore been limited for the present to two types, both of 

 which have been identified with previously described forms. 



The two bacteria investigated belong to the group of non-spore-formers 

 (discussed in an earlier publication (lo) as one of the three large groups 

 of soil microorganisms) and more specially to that division of this group 

 described as rapid liquefiers {p. lo, 6-g). One of them is Pseudomonas 

 fluorescens (Fliigge) Migula, described on page 6 of that bulletin. The 

 second is described on page 8 of the same bulletin as the "orange lique- 

 fying type," and has now been identified with Bacillus caudatus Wright. 

 As a single polar flagellum is present, it is renamed "Pseudomonas 

 caudatus (Wright)." 



1 Reference is made by number (italic) to "Literature cited," p. 347-3S0. 



Journal of Agricultural Research, Vol. XVI, No. 12 



Washington, D. C. Mar. 24, 1919 



rr Key No. N. Y. (Geneva)-5 



(313) 



