Decomposition of Stable Manures 



307 



According to Deherain, the function of the Httcr in manure consists 

 in absorbing the hquids excreted by the animals and in supplying 

 celluloses, substances which characterize the nature, decomposition 

 processes, and products resulting from the manure, and which give 

 the manure its special value for soil improvement. A knowledge of 



Original straw 



i 



Straw compost 



Fig. 122. Comparati\ e chemical composition of oat straw and of a compost pre- 

 pared from it ( from Waksman and Gerretsen ) . 



the chemical composition of the litter was, therefore, considered to 

 be of great importance. Konig emphasized that decomposition of 

 stable manures involves, first of all, the transformation of carbon 

 compounds present in the manures, and that 75 per cent of the car- 

 bon disappears within a year after application of the manure to the 

 soil. The decomposition is more rapid during the warmer periods 

 of the year than during the colder periods. 



Among the organic constituents of the manure, the pentosans and 

 cellulose are decomposed more rapidly than the total organic mat- 

 ter, whereas the lignins are decomposed more slowly. Decomposi- 

 tion of manure is thus accompanied by a rapid reduction in the car- 

 bohydrates and a gradual enrichment in the lignins. Both the total 



