750 



PRINCIPLES OF SOIL MICROBIOLOGY 



In 1894 Oberlin 44 applied CS 2 for the destruction of Phylloxera and 

 noticed that the productiveness of the soil was greatly increased. He 

 suggested, therefore, that soil sickness can be corrected by the appli- 

 cation of the disinfectant and ascribed this favorable influence to the 

 destruction of injurious microorganisms. This favorable effect of the 

 disinfectant was ascribed to the direct stimulation of young plants. 45 - 46 

 Nobbe and Richter 47 obtained a definite increase in crop yield by 

 treatment of soil with ether, chloroform or benzene. It was soon 

 found that the stimulating effect applies to all soils and all plants. 48 

 The antiseptics, like carbon bisulfide, carbon tetrachloride, toluol, 



^ ' added ' 7 - 



i2~ month 



Fig. 66. Influence of CS2 upon the numbers of bacteria and actinomyces in 

 the soil (from Hiltner and Stormer). 



benzol, phenol, cresol, are in themselves directly poisonous to plants 

 when added to water cultures. They were found to exert a decided 



44 Oberlin. Bodenmiidigkeit und Schwefelkohlenstoff. Mainz. 1894. 

 46 Koch, A. Untersuchungen liber die TJrsachen der Bodenmiidigkeit. Arb. 

 deut. landw. Gesell. H., 40. 1899, 44 p. 



46 Egorov, M. A. On the influence of carbon bisulfide upon soils and plants 

 (Russian). Zhur. Opit. Agron., 9: 34-95. 1908. 



47 Nobbe, F., and Richter, L. tJber die Behandlung des Bodens mit Ather, 

 Schwefelkohlenstoff, Chloroform, Benzol und Wasserstoffsuperoxyd und deren 

 Wirkung auf das Wachstum der Pflanzen. Landw. Vers. Sta., 60: 433^48. 

 1904. 



48 Stormer, K. Uber die Wirkung des Schwefelkohlenstoffs und ahnlicher 

 Stoffe auf den Boden. Jahresb. ver. angew. Bot. for 1907, 5: 113-131. 1908; 

 Centrbl. Bakt. II, 20: 2S2-28S. 1908. 



