52 TROPICAL AGRICULTURE CHAP. 



of food that is given to them. Young animals use most of 

 their food to build up their bodies ; and, consequently, the 

 manure from them is not so valuable as that from fully 

 grown ones. And animals that get rich food produce much 

 richer manure than poorly fed ones. For instance, horses 

 Well-fed fed partly on corn or oats, or seed cake, give a more valuable 



animals give . , f . , . . , 



the best manure than animals merely fed on grass ; and, in England 



ure * and elsewhere, cattle are often fed highly in order simply to 



enhance the value of their manure, and it is frequently 



found cheaper, in the end, to expend money in this way than 



in the purchase of artificial manures. 



5on mema ~ When farm yard manure is put in a heap it commences to 

 ferment, and this is caused by the rapid growth of myriads 

 of low vegetable organisms of the nature of moulds. This 

 fermentation produces heat and causes important changes 

 to take place in the manure, whereby it is rendered more fit 

 for the formation of plant food. Sometimes an odour of 

 ammonia is easily discovered, and this shows that the heap 

 is too dry and that water should be thrown upon it. And 

 when the heap is exposed and heavy rain falls on it, a stream 

 of black liquid stuff will run out. This is very valuable and 

 should not be lost. It ought to be collected and poured 

 back on the heap or on to the soil, where its high fertilising 

 action may be useful. This liquid manure contains am- 

 monia and other organic substances, and hence its value as 



png h eap plant food. If possible, the dung heap should be kept under 



under cover, cover, and then there will be no chance of heavy rains wash- 

 ing away its valuable substance. 



Compost is a kind of farm yard manure composed of all 

 the animal and vegetable refuse the planter can lay his 

 hands on. Weeds, dead leaves, road and gutter scrapings, 

 dead animals, kitchen waste, and any other thing of the 

 kind, are heaped up together and allowed to rot, when a 



conToSf valuable manure will be formed. Its value may be increased 

 by pouring some of the liquid manure over it, and by turn- 

 ing it sometimes, so as to assist the fermentation by allowing 



