CONCLUSIONS. 33 



(2) The lack of proper decay and liuinificatioii of organic matter in 

 many of the unproductive soils is due either to unfavorable bacterial 

 conditions brouglit about by certain physical and chemical conditions 

 or to an uiuisual bacterial flora. 



(3) The nitrifying bacteria in the soils of Fallon, Nev., are active 

 at greater depths than in eastern soils and also seem to be unusually 

 virile in solutions, although the data on these points are not con- 

 clusive. 



(4) In general, the conditions at Fallon, as in any arid region, favor 

 nitrification, which frequently becomes intense; the conditions rarely 

 favor denitrification. Lack of nitrification, therefore, will not be a 

 limiting factor in crop production, nor is there evidence of overnitrifi- 

 cation or injury from excessive quantities of nitrate. Humification 

 studies are probably of paramount importance. 



211 



