92 'rill': 1'i;incii'lks of AiiKUTLrrRK. 



three fourths of the vahic of these fertilizers may be 

 ohtaiiied in the first erop after they ai'e applied. 



In stable manure, only a small proportion of these 

 elements is soluble and available at first. Not more 

 than one foui'th of its ^■alue is ordinarily oI)tained the 

 first season. The remainder must wait for ehemieal 

 action slowly to reduce it to availa'ole foi-nis. 



The Care of Manui'e. — The value to be derived from 

 stable manure depends lari;'ely upon the care exercised 

 in preserving it. 



Prol)al)ly nearly one half the value of nrannre through- 

 out the country is lost. Some loss is, of course, unavoid- 

 able, but it may be largely prevented by proper care. 



There are three general sources of loss : — 



1. Fermentation. — Fermentation is a ju'ocess of de- 

 cay, or decomposition, which organic substances un- 

 dergo when brought in contact with moderately warm air. 

 The chemical process consists partly of oxidation, pro- 

 ducing heat. On this account, it is sometimes called 

 Jieatinfj. 



Some kinds of manure ferment much more readily and 

 rapidly than others. 



Sometimes, if the process is allowed to continue un- 

 checked, it will give to manure the ai)])earance of having 

 been i)artially burned, leaving only a light, unsubstantial 

 mass l)ehind. It is then said to l)e " fire-faugcd." 



By fermentation the most valuable elements of manure 

 are converted into gases, and tend to escape into the 

 atmosi)here. Nitrogen is converted into ammonia, and 

 carbon into carbonic acid gas. The loss of tlie former is 

 of far greater im|)ortance than that of the latter, since 

 carbon, which plants obtain so largely from the atmos- 

 phere, is of less value in manure. 



