148 



Storage of Farmyard Manure. 



Dietzell conducted an experiment with about 2kg". of ox 

 faeces, plus 10 per cent, of chaffed straw, the material being' 

 placed in flasks provided, in one case, with glass tubes reach- 

 ing to the bottom and attached to a respiration apparatus, so 

 that the manure was constantly subjected to the influence ot 

 a current of air ; while in the other set, air was not artificially 

 drawn through the mass. The experiment was conducted in 

 a room, the temperature of which varied between io"5 deg. C. 

 and 25 deg. C, and lasted from July 5th, 1S93, to January 

 30th, 1894. From time to time water was added, so that the 

 material was constantly kept in a moist condition. The per- 

 centage loss of dry organic matter is shown in the accompany- 

 ing table : — 





Per cent, of dry 



Without 

 artificial 



With 





culation. 





Manure 4- nothing - - - ' - . 



„ +2 %kainit -------- 



» + 3% gyp sum - - - - 



+0*38 % sol. phosp. acid in superphosphate 



+0*23 % citrate sol. phosp. acidin precipitated phosphate 



1 -04 



°'95 

 6-29 



O'OO 



5 '44 



45 -93 " 

 3"5 - 

 5 "-5 j 

 39 '49 

 41-07 



In this case the agents employed tended to prevent loss ol 

 organic matter only where the manure was constantly and 

 thoroughly aerated ; while oxidation was — as was to be 

 expected — much more energetic under these conditions than 

 where the mass was not subjected to artificial aeration. 



In a series of experiments, Pfeiffer placed 2kg. of ordinary 

 manure in a set of flasks, and by means of suitable apparatus 

 secured air-circulation over the mass in one case and through 

 the mass in the other. The result was that at the end of ten 

 months there was practically as much loss of organic matter 

 in the one case as the other. 



In another series of experiments he placed ;kg. of manure 

 — -consisting of a mixture of solid and liquid bovine excreta 

 and moss litter — in each of a set of zinc cylinders, the 

 manure in one case being loosened ever)- eighth day, while 



