FARM MANURES 



175 



The composition of the manure influences the fer- 

 mentation. The presence of considerable amounts 

 of soluble nitrogen hastens the rapidity of the fer- 

 mentation. 



Now when the manure ferments a large part of 

 the organic matter in it is broken down and changed 

 into gases. The gas formed most abundantly by 

 the fermentation is carbonic acid gas, which is pro- 

 duced by the union of oxygen with carbon of the 

 organic matter. The formation of this gas means 

 a loss of humus. This loss can be noticed by the 

 fact that the pile gradually becomes smaller. 



The next most abundant product of the fermenta- 

 tion is water vapor which can often be seen pass- 

 ing off in clouds of steam. 



When manure ferments rapidly the nitrogen in it 

 is changed largely into ammonia. This ammonia 

 combines with part of the carbonic acid gas and 

 forms carbonate of ammonia, a very volatile salt 

 which rapidly changes to a vapor and is lost in the 

 atmosphere. This causes a great loss of nitrogen 

 during the rapid decomposition of the manure,, 

 This loss can be detected by the well known odor 

 of the ammonia which is particularly noticeable 

 about horse stables and piles of horse manure. 



Besides these gases a number of compounds of 

 nitrogen, potash, etc., are formed which are soluble 

 in water. It is these that form the dark brown 

 liquid that sometimes oozes out from the base of 

 the manure heap. 



At the Cornell University Agricultural Experi- 



