1921.] 



Artificial Farmyard Manure. 



411 



A ludf/fical Data. 



Calculated Data. 



lb. 



Nitrogen sii})plie(l in food 

 Nitrogen „ „ litter 



Indig. (fa'cal) nitrogen... = 27G 

 Nitrogen in litter ... = 100 

 Nitrogen tixed by litter 



(l(')-3rj2 lb. (a 91 per 



Total nitrogen 



713 



cent, dry matter x 0*72, 



i.e.y fixation constant) = 107 

 Nitrogen as ammonia ... = 54 



Total nitrogen recovered 

 in dung 



524 



Total calculated 



= 537 



Similar calculations have been made in the case of 

 other feeding experiments, but these two instances will probably 

 suffice to show that the amount of nitrogen which we found 

 straw to be capable of fixing in the laboratory, is also most 

 probably built up into organic form and to the same extent 

 under ordinary farm conditions. It is, perhaps, outside the 

 scope of this paper to suggest means by which the observed 

 losses which occur in the making of manure may be minimised, 

 but rational practice would appear to lie in the direction of a 

 more liberal use of litter in order to increase the amount of 

 ammonia that can be fixed, with the further result of a con- 

 siderable increase in the dung-making capacity of a given 

 number of stock. 



