MANURES. 185 



From these calculations it will be seen that the urine is of 

 great value and that it is important for every farmer to use 

 freely litter, muck or other substances for its absorption. 



Very important questions arise as to the time when barnyard 

 manure sliould be put into the ground, and the manner in 

 which it should be kept until so used. 



Practical agriculturists, by various experiments upon a large 

 scale, have demonstrated that barnyard manure turned under 

 the soil in a fresh and unfermented state is of greater value 

 than when left to rot and ferment in the dung-heap, even when 

 that is properly protected ; and the practical results in this 

 accord with sound theory, as in the process of fermentation 

 and decay, gases escape which are of value to vegetation. If 

 not immediately turned under the soil, manure should be kept 

 where it will properly ferment, without being exposed to heavy 

 rains, and if so kept, the amount of gases which escape is not 

 great, and the mineral substances are not affected, and manure 

 rotted in such a position, although much reduced in quantity, 

 is more immediate in its effects, and nearly as valuable in its 

 properties, as when carted upon the land in a fresh state. 

 Experiments show that the amount of actual loss in manure 

 thus cared for is very slight. But if the manure is exposed to 

 heavy rains its depreciation is very great, as a large portion of 

 its mineral substances is washed from the heap and lost. In 

 accordance with these views I would suggest whether there is 

 any appreciable loss from spreading barnyard manure upon the 

 surface of the ground intended to be enriched, and allowing it 

 to remain for a length of time without being covered with the 

 soil. Being thinly spread there will be but little fermentation, 



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