Farmyard Manure. 



291 



worth of artificial manure, and if a ton of dung is not usually 

 valued at even half these figures this is chiefly because a large 

 part of the three substances mentioned never becomes available, 

 or is lost before crops can make use of it. True, a ton of farm- 

 yard manure is more expensive to handle than 2 or 3 cwt. of 

 artificials, and this, of course, reduces its relative value ; but, on 

 the other hand, farmyard manure has a beneficial influence 

 on crops just because it is a heavy bulky substance, so that these 

 two considerations may be held roughly to balance or cancel 

 each other. 



Variation in the Quality and Character of Dung, 

 This is affected by : — 



The Kind of Food : Food rich in fertilizing materials, especi- 

 ally nitrogen, produces rich dung. 



The Kind of Animal : Horses produce dry, hot dung that 

 ferments and acts quickly, but does not last long, whereas 

 the dung of cattle and pigs is cold, slow-acting, and more 

 durable. The dung of young stores and dairy cows is 

 rather poor in all the important elements of plant-food, 

 because, in the former case, these elements have, to a 

 relatively large extent, gone to form bone and muscle, 

 while in the latter case they have found their way into the 

 milk. For instance, to quote the Rothamsted figures, while the 

 excreta of a fattening bullock getting decorticated cotton cake 

 will confain about 97 per cent, of the nitrogen, 96 per cent, of 

 the phosphoric acid, and 99 per cent, of the potash present im 

 the cake, the corresponding figures for a milk cow are only 

 87 per cent, for the nitrogen, 89 per cent, for the phosphoric 

 acid, and 86 per cent, for the potash. This means that for 

 every 3 lb. of nitrogen, 4 lb. of phosphoric acid, and 1 lb. of 

 potash that the fattening bullock abstracts, the milk cow 

 appropriates 13 lb., 11 lb., and 141b. respectively. 



The Age of the Dung: Rotten dung is richer and more 

 active, provided it has been properly " made," than comparatively 

 fresh undecomposed material. 



The Manner of Storage : Properly-managed dung is more 

 valuable than that which has been mismanaged. 



