530 



PRINCIPLES OF SOIL MICROBIOLOGY 



In alkaline soils which are deficient in humus, CaC0 3 may have 

 the opposite effect since it tends to liberate from ammonium salts free 

 ammonia, which retards nitrification. 



Lime does not stimulate the activities of the nitrifying bacteria 43 

 so much as it serves as a base for neutralizing the acid formed from the 

 oxidation of the ammonium salt. Nitrate formation takes place 

 readily in peat and muck soils 44 if the reaction is not too acid and if 

 the soil is properly inoculated with the organisms. Acid peat soils 

 do not generally offer a favorable medium for the development of the 

 nitrate forming bacteria. When lime is added, these organisms become 



TABLE 52 

 Influence of application of lime upon nitrogen content and nitrification of 



a muck soil 



mann, O., Fischer, H., and Husek, B. fiber den Einfluss verschiedener Basen 

 auf die Umwandlung von Ammoniakstickstoff und Nitratstickstoff. Landw. 

 Vers. Sta., 70: 317-342. 1909; Fred, E. B. A study of the formation of nitrates 

 in various types of Virginia soils. Centrbl. Bakt. II, 39: 455-468. 1913; Mil- 

 ler, F. Tiber den Einflusz des Kalkes auf die Bodenbakterien. Ztschr. Giirungs- 

 physiol., 4: 194-206. 1914; White, J. W. Nitrification in relation to the reaction 

 of the soil. Ann. Rpt. Penn. Agr. Exp. Sta. 1913-14, 70-84. 



43 Stephenson, R. E. Nitrification in acid soils. Iowa Agr. Exp. Sta. Res. 

 Bui. 58. 1920; Temple, J. C. Nitrification in acid or non-basic soils. Ga. 

 Agr. Exp. Sta. Bui. 103. 1914. 



44 Arnd, Th. Beitrag zur Kenntnis der Mikrobiologie unkultivierter und 

 kultivierter Hochmoore. Centrbl. Bakt. II, 45: 554-574. 1916; Uber die 

 Entstehungsweise sal peter und salpetrigsaurer Salze in Moorboden. Landw. 

 Jahrb., 51: 297-328. 1918. 



