210 Agricultural Bacteriology. 



Much of this loss can be prevented by the use of proper 

 methods which will be described later. 



In the manure heap the ammonia is not changed into 

 nitrates as it is in the soil for the conditions are not fav- 

 orable for the nitrifying bacteria. Organic matter is too 

 abundant and oxygen is also lacking except in the outer 

 layers of the pile. If the manure is allowed to stand, 

 especially if it has been mixed with earth, until it is com- 

 pletely decomposed, a small amount of nitrate will be 

 found. Since no nitrates are formed, denitrification can- 

 not take place. 



Cellulose decomposition. The decomposition of the 

 cellulose begun in the animal is continued in the manure 

 pile by the same kind of bacteria as in the body of the 

 animal. The starches and sugars, etc., are also readily 

 fermented by micro-organisms, and carbon dioxide, 

 water, hydrogen, and organic acids are formed. 



Losses from manure. It is impossible to return to 

 the soil all of the organic matter removed in the crop, 

 even though the entire crop is fed to farm animals and 

 the manure carefully handled. In the respiration of ani- 

 mals a large amount of carbon is eliminated from the 

 body ; this was taken^ in with the food. Oxygen and hy- 

 drogen in the form of water are given off as respiratory 

 products and in the perspiration. The nitrogen and 

 mineral ingredients are eliminated in the same amounts 

 as are contained in the food consumed, except for the 

 quantity retained in the tissues of the animal. This is 

 of course much more, in the case of a growing than a ma- 

 ture animal. 



In the decomposition processes in the manure pile, the 

 organic matter is destroyed, which is in itself a loss to 

 the soil, since if applied to the land, it would have fur- 



