534 



The Storage of Farmyard Manure 



would be more than under anaerobic conditions. But any such 

 increased ammonia production is wholly masked by the new change 

 whereby nitrogen is lost. 



An increase in temperature to 26° causes some increase in the amount 

 of decomposition of the dry matter but not in the loss of nitrogen. 

 There is, however, an increased loss of ammonia and no indication of 

 a gain as in the anaerobic experiments. Similar results were obtained 

 whether we worked with 5 grams of manure or 500. 



The fact that nitrogen is lost under aerobic conditions was also 

 shown by Sjollema and de Wildt in their experiments at Gronigen 

 during the years 1906-10^. They made up an artificial mixture of 

 faeces and urine, and allowed it to ferment (a) under anaerobic conditions 

 at 15° C. and at 35° C, and (b) under aerobic conditions at the same 

 temperatures. The results were : 



(1) 2 kilos faeces + 200 c.c. urine left for 2 months. 



Difference at end 



* In this experiment at 35° C. the initial quantities were not quite the same as in the 

 others. 



(2) 2 kilos faeces + 50 c.c. urine diluted to 200 c.c. left i\ months. 



Difference at end 



Anaerobic conditions Aerobic conditions 



^ Verslag. Landbouivk. Onderzoek. Rijkslandbouwproefstat. No. 1, p. 21, 1907; No. 7, 

 p. 10(3, 1910. 



