MANURES. 



mechanical as well as the chemical condition of the 

 soil. 



4. We are now enabled to see how lime prepares 

 the constituents of the soil for the use of plants. 



By its action on the roots, buried stubble, and other 

 organic matter in the soil, it causes them to be decom- 

 posed, and to give up their constituents for the use 

 of roots. In this manner the organic matter is 

 prepared for use more rapidly than it would be, if 

 there were no lime present to hasten its decomposi- 

 tion. 



By the decomposing action of lime on the mineral 

 parts of the soil (3), they also are placed more rapidly 

 in a useful condition than would be the case, if their 

 preparation depended on the slow action of atmo- 

 spheric influences. 



Thus we see that lime, aside from its use directly 

 as food for plants, exerts a beneficial influence on 

 both the organic and inorganic parts of the soil. 



5. Many farmers assert that lime exhausts the soil. 

 If we examine the manner in which it does so, we 



shall see that this is no argument against its use. 



It exhausts the organic parts of the soil by decom- 

 posing them, and resolving them into the gases and 

 minerals of which they are composed. The gases 

 arising from the organic matter cannot escape ; be- 

 cause there is in all arable soils a sufficient amount 

 of clay and carbonaceous matter present to cause 

 these gases to be retained until required by the roots 

 of plants. Hence, although the organic matter of 

 manure and vegetable substances may be altered in 



