148 SOILS AND FERTILIZERS 



ive. The anaerobic ferments prepare the way for the 

 action of the aerobic bodies. When aerobic fermenta- 

 tion is completed the organic matter is converted into 

 water, carbon dioxide, ammonia and allied gases. 

 From what has been said regarding the action of these 

 two classes of ferments it is evident that anaerobic 

 fermentation is the most desirable. 



Fig. 26. Fermentation of Manure. 



186. Water Necessary for Fermentation. In order 

 to produce the best results in fermenting manure, 

 water is necessary. If the manure becomes too dry 

 abnormal fermentation takes place. Water is always 

 beneficial on manure so long as leaching is prevented; 

 for it encourages anaerobic fermentation by excluding 

 the air. An excessive amount of water, such as falls 

 on piles from the eaves of buildings, is more than is 

 required for good fermentation. During a dry time it 

 is beneficial, if conditions admit, to water the com- 

 post pile. 



187. Heat Produced During Fermentation. Dur- 

 ing active fermentation of horse and sheep manure, a 

 temperature of 175 F. may be reached by the fer- 

 menting mass. Ordinarily, however, the temperature 



