3 72 rniversify of California Puhlication.'i in Agricultural Sciences [Vol. 1 



1.3. Experiments are following those above described to make 

 the latter more complete. Elaborate tests are being made with 

 many soil types using the original soil 's mixed flora from freshly 

 collected samples in the field. Not only ammonifying powers of 

 these mixed flora in the different soil types will be studied, but 

 also the corresponding nitrifying powers. A large variety of 

 nitrogenous fertilizers as employed in practice will be tested here. 



EEFERENCES OF MORE OR LESS DIRECT PERTINENCE 



1 Bull. Acad. Roy. Soc. Belg., 3 ser., vol. 25, p. 727. 



2 Voorhees, Fertilizers, Maemillan Co., 1898. 



3 N. J. Sta. Bulletin, no. 246. 



■i Ann. Sei. Agron., vol. 19, p. 209. 



■■ Rpt. Del. Exp. Sta., 1899, p. 76. 



6 Cent, fiir Bakt., 2'<^ Abt., vol. 20, p. 322. 



- lUd., vol. 15, p. 433. 



s Ibid., vol. 29, p. 238. 



'•> Ibid., vol. 31, p. 49. 



