CONCLUSIONS. 33 
(2) The lack of proper decay and humification of organic matter in 
many of the unproductive soils is due either to unfavorable bacterial 
conditions brought about by certain physical and chemical conditions 
or to an unusual 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 
