56 THE SOILS AND CROPS OF THE FARM. 



physical condition better or worse, but plants cannot 

 feed upon them until they have rotted. In many cases 

 it is wise to immediately apply stable manure, but it 

 cannot act as plant food until fermentation has com- 

 menced. 



Fermentation begins promptly. Especially horse 

 manure and this loosely piled, will very soon become 

 hot, and carbonic acid will rapidly pass into the 

 air, greatly reducing the weight and bulk, but with- 

 out much reducing the direct value of the manure, 

 unless it has been t^o dry and "iire-fanged." If 

 kept saturated with water, fermentation is checked 

 unduly. Unless litter is freely used there is a consid- 

 erable loss of aramonia while the manure is fresh. 

 The use of gypsum or even of earth will check this 

 loss. Keeping the manure moderately moist and well 

 compacted will best prevent loss of nitrogen. If 

 necessary to keep it in heaps for a considerable time, 

 covering the heaps with a layer of earth will still 

 further prevent loss. 



In many cases the loss from water is much more 

 important than that by evaporation or vaporization. 

 If manure i^ scattered about yards or piled under the 

 eaves of stables, more than half its value may be lost 

 in a few months. The water carries away much of 

 the nitrogen and some of the potash. 



Manure kept under cover, if kept sufficiently moist, 

 is more valuable than that kept in the open air. 

 Many farmers, with present arrangements, cannot 

 keep the manure in either boxes or under sheds. If 

 they keep it in reasonably compact piles, not exposed 

 to washing from eaves of buildings, the loss will not 

 be especially serious. 



