The Golden Age of Soil Microbiology 



19 



methods were further de\eloped and improved by Lohnis in 1904- 

 1905. 



Unfortunately, detailed studies of these methods have shown that 

 a liquid culture medium in the laboratory does not present conditions 

 comparable to those that exist in normal soils. The soil itself was 

 then substituted for measuring the rate of chemical change that 

 could be produced in a given substance. Such substance was added 

 to the soil and was allowed to remain there for a definite period of 



Fig. 12. V. L. Omeliansky first isolated tlie anaerobic cellulose-decoinposiug 



bacteria. 



time under favorable temperature and moisture conditions. This led 

 to the development of the "tumbler" or "beaker" method by J. G. 

 Lipman and P. E. Brown. To measure the rapidity of ammonia for- 

 mation from an organic nitrogenous material, a protein or a protein- 

 rich substance, such as dried blood or peptone, was added to the 

 soil. To measure the rapidity of nitrate formation, ammonia in the 

 form of one of its salts or an organic nitrogenous substance was 

 added to the soil. To measure the nitrogen-fixing capacity of a soil, 

 a soluble carbohydrate was used; the soil was brought to optimum 

 moisture condition and allowed to incubate for 7-30 days; the amount 

 of nitrogen fixed was then measured. 



