CHAPTER XIV 



FARMYARD MANURE 



Ix many respects farmyard manure is the most im- 

 portant of all manures. It is produced in the ordinary 

 course of farming, and consists essentially of those parts 

 of the crops that are unsuitable for use as foods, mixed 

 with the droppings of the animals. It is the medium 

 by which the surplus plant foods taken from the soil 

 are restored to it. The fertility of the land is thus 

 maintained at its normal level, but cannot generally be 

 increased beyond that point by this means. The avail- 

 able plant foods derived from a given area of land during 

 the rotation are, however, concentrated in the manure 

 and can be applied in large quantity to those crops 

 which most particularly require them. The fertilising 

 effects of farmyard manure are well known and are all 

 the more conspicuous because it is usually applied to 

 land which has become partially exhausted during the 

 rotation. The essential function of farmyard manure is 

 restoration, and previous to the introduction of the so- 

 called artificial fertilisers and feeding stuffs, it could 

 not be employed to increase the fertility of one piece of 

 land beyond a certain point without reducing that of 

 another in a corresponding degree. When these sub- 

 stances are used, the farmyard manure has naturally a 

 much wider scope. 



Within certain limits the composition of farmyard 

 manure is very variable. The causes and extent of this 

 variation are amongst the most important points to be 



S.M. x 



