TRANSFORMATION OF ORGANIC MATTER 



703 



Surface. Soil 



80.001 



70000 



60.000 



JO.000 



40.000 



30.000 



^ 



hf 



\l 



\L 



V^ 



\\ 



;/ 



.Ccibcn 



.flitroqen 



Carbon 



i ^ I 'i l s 1 



£ <o 3} <*} '^ VI 



Fig. 57. Carbon and nitrogen content of Carrington silt loam (Brown and 

 O'Neil). 



the organic matter as an available source of energy, soil microorganisms 

 may assimilate as much as 10 to 49 per cent of the carbon of the original 

 material and convert it into microbial protoplasm. The latter contains 



