AGE AND KIND OF ANIMAL 1 55 



fertility. A hen produces about a bushel of manure 

 per year. 55 



Composition of Hen Manure. 



Per cent. 



Water 57-5o 



Nitrogen 1.27 



Phosphoric acid 0.82 



Potash o. 28 



186. Mixing of Solid and Liquid Excrements. — 



The solid and liquid excrements, when properly mixed, 

 make a well-balanced manure. The urine alone is not 

 a complete manure, as it is deficient in phosphoric acid 

 and other mineral matter. The solid excrements and 

 the urine, when mixed with soil, readily undergo nitri- 

 fication. The nitrogen in the solid excrements is in 

 the form of indigestible protein, and is rendered avail- 

 able as plant food more slowly. Land which has 

 been heavily dressed with leached manure has re- 

 ceived an unbalanced manure, and is deficient in 

 nitrogen but fairly well supplied with mineral matter. 

 Such a soil may fail to respond because of the unbal- 

 anced character of the manure. 



187. Volatile Products from Manure. — The fer- 

 mentation of manure in stables may cause the pro- 

 duction of a large number of volatile compounds. The 

 ammonia and nitrogen compounds are products which 

 cause losses of value to the manure. Urea, when it 

 ferments, produces ammonia or ammonium carbonate. 

 If ammonia is produced it combines with the carbon 



