Supplying Soil Needs 



183 



u. K. n. A. 



FIG. 140. In a covered barnyard like this, manure can be saved with little 

 loss through leaching. 



strong odor of ammonia gas (containing nitrogen) that 

 is often to be noticed about stables. Sometimes the 

 heat of the chemical action becomes so great that the 

 manure becomes " fire-fanged " ; that is, it turns white 

 like ashes and is not of much more value than ashes. 



A compost -heap is a mixture of manure, soil, refuse Compost 

 such as weeds, and plants left in the garden after the 

 crop is gathered (Fig. 141). Bean and pea vines are 

 especially valuable, since they contain much nitrogen. 

 Matter that might otherwise be wasted is deposited in 

 the compost heap, and the bacteria turn it into material 

 that is excellent for greenhouse work and for use in 

 seed boxes. 



Flies very commonly carry disease, and that is the 



