24 



HUMAN AND ANIMAL WASTES 



stuffs (454). As soon as voided, manure begins to undergo rapid de- 

 composition. This results in the formation of ammonia (140) and vari- 

 ous other nitrogenous degradation products (290). These give rise to 

 offensive smells, which are controlled by the conditions of decomposi- 

 tion. From a sanitary point of view, it is essential that decomposition 

 should be accompanied by the destruction of the injurious organisms 

 present in the manure. The fecal organisms gradually disappear and 

 their place is taken by a population concerned in the decomposition of 

 cellulose, hemicelluloses, and proteins (922). 



The decomposition of complex plant and animal residues leads to a 

 rapid reduction in carbohydrates and is accompanied by the evolution 

 of considerable heat, the temperature of the compost reaching as high 

 as 80° C, as shown in Figure i. 



In order to hasten the decomposition of manure, conditions must be 

 favorable to the activities of microorganisms. It must be properly 



15 20 25 30 35 40 45 

 COMPOSTING PER.IOD IN DAYS 



50 55 60 65 



Figure I. Influence of straw bedding upon temperature changes in the 

 composting of manure. Circles indicate times of turning composts. From 

 Waksman and Nissen (940) 



