LOSS 203 



(b) Anaerobic. — When air is not present in manure, 

 decomposition and loss of ammonia are not so rapid. While 

 urea may change to ammonium carbonate there is no op- 

 portunity for this compound to break up into ammonia, 

 carbon dioxide, and water. The proteins of the solid portion 

 are slowly changed to soluble compounds and some ammonia, 

 but the latter is not lost to any great extent. Moreover, 

 much of the nitrogen so changed is absorbed by the bacteria 

 themselves and retained in the manure as insoluble com- 

 pounds. 



The non-nitrogenous portions of the manure are broken 

 down into organic acids, carbon dioxide to some extent, and 

 in addition considerable quantities of hydrogen and methane. 

 Sulphur is likely to be changed in part at least to hydro- 

 gen sulphide. Moreover, considerable quantities of black 

 "humus" are formed. The straw and other litter lose their 

 original fibrous condition and become a part of the dark, 

 fine mass of " well-rotted manure." Under anaerobic con- 

 ditions the loss of carbon dioxide, water, hydrogen, and 

 methane results in loss of weight. 



202. Molds. — Particularly in loose, dry manure, molds 

 develop and cause destruction of both nitrogenous and 

 non-nitrogenous compounds. "Fire fanging" is a result 

 of the growth of molds on horse manure, resulting in the 

 appearance of a white, powdery coating on the material. 



203. Loss. — The above mentioned changes are what take 

 place under special conditions. Considering now an ordinary 

 manure pile, such as is altogether too common even now, 

 it will be interesting to note what happens. Such a pile is 

 only moderately compact; loose on the outside at any rate, 

 and exposed to the weather. Both aerobic and anaerobic 

 decomposition take place. Urea changes rapidly to ammo- 

 nium carbonate and ammonia. Proteins are changing to 

 ammonia. Ammonia is being oxidized to free nitrogen as 

 well as passing off into the air. Carbon dioxide and water 

 are being formed in considerable quantities as well as some 

 hydrogen and methane. The pile shrinks in volume, losing 

 weight constantly. Humus-like substances form, many of 

 which are dissolved out bv a solution of alkaline carbonates 



