246 FARMYARD MANURE [chap. 



lies about in the yard, the greater will this loss become. 

 On the other hand, when food is fed upon the land and 

 is not used for making manure in yards or stalls, as, 

 for example, when the sheep are folded on the land or 

 cattle are given cotton cake while they are grazing, the 

 losses of nitrogen would be much reduced, because 

 the urine which contains the valuable part of the 

 nitrogen is at once absorbed by the soil, and none of 

 the usual wasteful actions are set up. On the other 

 hand, a farm producing much milk takes rather more, 

 both of phosphoric acid and nitrogen, out of the food than 

 the proportions we have been assuming, so that dung 

 made by milch cows is never very rich. But taking 

 all these things into account, we shall not be far 

 wrong in assuming a loss of half of the nitrogen under 

 the ordinary conditions of mixed' farming, and in 

 thereby deducing compensation values in the manner 

 we have set up above. 



We can apply the same principles to obtain the 

 value of a ton of farmyard manure. Of course, as a 

 rule, the farmyard manure is a normal product of the 

 farm, and the only problem is to make it as carefully as 

 possible, and apply it to the best purpose afterwards. 

 But there are occasions, especially in growing of crops 

 like market garden produce, potatoes, hops, when it 

 becomes a question of whether it is more profitable to 

 buy farmyard manure or artificial fertilisers, or to keep 

 stock in order to make the farmyard manure that is 

 required. It will be found that if the farmyard manure 

 account is charged with the litter, and the compensation 

 values of the foods calculated in the fashion described 

 above, on the assumption that half of the nitrogen, 

 three-quarters of the phosphoric acid, and all the potash 

 contained in the food found its way into the manure, 

 then the farmyard manure will cost from 8s. 6d. to 12s. 



