6 



508 NATURE AND PROPERTIES OF SOILS 



manure. The protected manure was stored in a bin under 

 a shed. The exposed sample was in a similar bin but unpro- 

 tected. 



Table CVIII 



LOSS OP CONSTITUENTS FROM PROTECTED AND UNPROTECTED 



MANURE. 



288. The fermentation and putrefaction of manure. 1 — 



In the process of digestion, the food of animals becomes more 

 or less decomposed. This condition comes about partly be- 

 cause of the digestive process and partly from the bacterial 

 action that takes place. Of these two influences within the 

 animal, bacterial activities are probably of the greater im- 

 portance as far as the breaking-up of the complicated food- 

 stuffs is concerned. The fresh excrement, then, as it comes 

 from the stable, consists of decayed or partially decayed 

 plant materials, with a certain amount of broken-down animal 

 tissue and mucus. This is more or less intimately mixed with 

 litter and the whole mass is moistened with the liquid excre- 

 ment carrying considerable quantities of soluble nitrogen and 

 potash. This mass of material, ranging from the most com- 



1 Good general discussions may be found as follows: Lipman, J. G., 

 Bacteria in Belation to Country Life, pp. 303-356; New York, 1911. 



Hall, A. D., Manures and Fertilizers, pp. 184-210; New York, 1921. 



For a technical discussion see Eussell, E. J., and Richards, E. H., The 

 Changes Taking Place During the Storage of Farm Manure; Jour. Agr. 

 Sci., Vol. VIII, Part 4, pp. 495-563, Dec, 1917. 



