DECOMPOSITION OF PROTEINS 



499 



amino acids with nitrous acid, but this loss is comparatively small. 

 Niklewski 74 found that the greatest loss of nitrogen from the stable 

 manure is a result of the action of the nitrifying bacteria. Only about 

 3 per cent of the nitrogen was lost, largely as ammonia, when manure 

 was kept for 255 days free from nitrifying bacteria. In the presence 

 of a large amount of urine, 5 to 12 per cent of the nitrogen was lost. 

 Manure inoculated with nitrifying bacteria lost about 20 to 24 per 

 cent of its nitrogen. This is due chiefly to the fact that the nitrates 

 are reduced rapidly as soon as formed and elementary nitrogen is lost 

 into the atmosphere. 



Fig. 29. Apparatus for study of ammonia formation in the decomposition of 

 manure (from Conn and Collison). 



According to Russell and Richards, 75 there is a distinct difference 

 in the transformation of nitrogen compounds in the manure when 

 stored under anaerobic or aerobic conditions. There was practically 

 no loss of nitrogen under anaerobic conditions; the proteins were de- 

 composed with the formation of ammonia, particularly at the higher 

 temperature. Under aerobic conditions, there was a great loss of 

 nitrogen, the amide form practically disappeared, while most of the 

 ammonia was transformed into nitrites or nitrates. In general, under 

 anaerobic conditions, the loss of dry matter and nitrogen is at a mini- 



74 Niklewski, B. t)ber die Bedingungen der Nitrifikation im Stallmist. 

 Centrbl. Bakt. II, 26: 388-442. 1910; Rocznikow Nauk Rolniczych, 9: 1-18. 

 1923. 



75 Russell, E. J., and Richards, E. R. The changes taking place during the 

 storage of farmyard manure. Jour. Agr. Res., 8: 495-563. 1917. 



