BARNYARD MANURE 95 



has disappeared or been slowly " burned," for rotting is a 

 kind of slow burning. A roof over the manure pile pre- 

 vents the great loss caused by water, but the other losses 

 go on even with the roof. The best plan, therefore, is to 

 put manure into the ground as soon as possible and before 

 any waste has occurred. 



Composts. Compost heaps are piles of manure mixed 

 with other materials, such as leaves or cotton seed, with 

 sometimes phosphate added. Partial rotting makes the 

 manure less coarse and makes it act more quickly on the 

 crop. The same materials can be mixed in the furrow in 

 the field. When they rot there, the soil prevents loss. 

 Moreover, when organic matter rots in the soil, it causes 

 the soil touching it to " rot " too, that is, to change some 

 of its compounds into substances that plants can use as 

 food. It is generally best to plow manure under so that 

 the soil will absorb the ammonia that might otherwise be 

 lost. 



Barnyard manure is dilute. The farmer must get it to 

 the field with as little labor as possible, for fully three fourths 

 of its weight is water, that has no value. Large amounts 

 must be used on an acre. In a ton of manure there are 

 only about 25 to 35 pounds of the three precious forms of 

 plant-food (nitrogen, phosphoric acid, and potash), or about 

 as much as in 200 pounds of a high-grade complete com- 

 mercial fertilizer. The plant-food in a -ton of manure could 

 generally be bought in the form of commercial fertilizers 

 for between $1.50 and $3. But a ton of manure contains, 

 besides direct plant-food, billions of helpful germs and 

 about a quarter of a ton of organic matter that is very 



