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The fermentations of manure are very complex and vary according 

 to circumstances. The principal conditions affecting these processes 

 are (1) temperature, (2) supply of air as determined by compactness of 

 heap, (3) moisture, (4) the composition of the manure, and (5) the 

 nature of preservatives added. 



The higher the temperature the more rapidly 'will manure decay. In 

 aerobic fermentation of manure the temperature may rise to 122° to 140° 

 or even 158° F. On the other hand, in the interior of the heap, where 

 anaerobic fermentation is in progress, the temperature rarely rises 

 above 96° F. Experiments have indicated that 131° F. is the most 

 favourable temperature for manure fermentations. 



As already explained, the supply of air determines whether the 

 elow-acting anaerobic ferment or the more vigorous aerobic ferment 

 predominates. The careful regulation of the two kinds of fermentation 

 is necessary to the successful rotting [of manure. If the heap is too 

 loosely built the decomposition is too rapid. The materials useful for 

 the formation of humus in the soil are destroyed, and the nitrogen, 

 especially that of the urine, escapes into the air, largely in the form 

 of ammonia. On the other hand, if the manure is too firmly packed 

 the decomposition may be too slow and the manure will not become 

 sufficiently disintegrated to produce the best effect in the soil. 



A powerful means of controlling fermentation is the supply of mois- 

 ture. The addition of water lowers the temperature and thus retards 

 fermentation. By filling up the pores of the mass and excluding 

 the air it checks aerobic fermentation when this becomes too active. 

 French authorities maintain that the principal precautions necessary to 

 prevent losses of ammonia consist simply in regularly and properly 

 watering the manure with the leachings. In case of drought, if the 

 teachings are insufficient, the lack should be made up with water. 



The need of keeping manure moist is especially marked in case of 

 horse manure, which is naturaUy dry and decomposes with great 

 rapidity. The same is true in a less degree of sheep manure. The 

 common and harmful " fire-fanging" is the result of an insufficient 

 supply of water and may be readily checked by sprinkling. The 

 epnnkling, however, should be regularly done and the heap kept in a 

 constant state of moisture, otherwise the alternate wetting and drying 

 will result in a loss of ammonia. Preservation of manure in this manner 

 is generally practised in Europe and the product obtained is highly 

 esteemed as a fertiliser. It is, " very dark coloured, or even black, and 

 acquires a highly offensive odour, while the straw in it loses its consist- 

 ency and become soft and incoherent." This black substance is held 

 by certain French agriculturists to possess special value as a plant 

 food. A method employed in the preparation of this well-rotted 

 manure in France is as follows : The manure is placed on slightly 

 inclined plats of packed earth or cement, so arranged that the leach- 

 ings drain out into a pit from which they are pumped up and distributed 

 over the manure heap. It is usual to provide two manure plats so 

 arranged that when one is full (when the manure is 8 to 10 feet high) 

 it may be allowed to ferment undisturbed while the other is used. The 

 manure is carried from the stables to the top of the manure heap in 

 wheelbarrows over an inclined plane of boards. Care is also taken to 

 smooth down the sides of the heap to prevent the too free access of air 



