NATURAL MANURES. 57 



manure heap. The value of this practice is, however, 

 measured by the care of the manure afterward, since the 

 fixed constituents are still liable to loss from leaching. 



The Improvement of Manures. Manures are im- 

 proved as they are reduced in bulk, and as the constit- 

 uents are made available or directly useful; this is 

 accomplished by well-regulated fermentation, or rotting. 

 By well-regulated fermentation is meant that which re- 

 sults in the decay of organic matter with the least loss 

 of nitrogen. The loss from fermentation is greatest 

 when the manure lies in loose heaps, the access of air 

 aiding the decay; the loss is least when it is packed 

 and moist. The mixing of the manures of the various 

 farm animals, hot and cold, also tends to reduce fermen- 

 tation. 



If the fermentation becomes too active, great heat is 

 developed, which causes the rapid escape of moisture; the 

 manure is burned and has a whitish and mouldy appear- 

 ance, it is what is called " fire-fanged." Under these 

 circumstances there is frequently a loss of nitrogen. The 

 " fire-fanging " may be prevented by keeping the heap 

 moist. 



It is evident, therefore, that the improvement of 

 manures, while it reduces bulk and increases availability 

 of the fertilizing elements, requires care and labor. 

 Whether such improvement will pay or not depends, 

 first, upon the cost of labor, and second, upon the object 

 of use of the manure. Where labor is expensive, and 

 the manure is used for the growing of such gross-feed- 

 ing field crops as corn, the advantages derived are least. 

 When the handling can, be performed by the regular 



