182 FARM-YAED MANURE. 



former has double the vahie of the other. By the removal 

 of the Diiueral constituents of the corn, which were de- 

 rived from the manm^e, the efficacy of the manure with 

 regard to future corn crops is constantly diminished. 



From whatever point of view, therefore, the alienation 

 of corn or other field produce may be regarded, the farmer 

 who does not replace the mineral constituents taken away 

 in the crops, will find that the inevitable result is exhaus- 

 tion of the soil. Continued removal of the corn crops 

 makes the ground unproductive for clover, or deprives the 

 manure of its efficacy. 



In our exhausted fields the roots of cereals no longer 

 find, in the upper layers of the soil, sufficient nutriment 

 for the production of a full crop : the farmer, therefore, 

 grows on these fields clover, tm-nips, and other plants of 

 the kind, which, with their wide-spreading and deep 

 roots, penetrate in all directions through the soil, open up 

 the ground by their large root-suiface, and appropriate 

 the constituents which are needed by cereals for the for- 

 mation of seed. In the residue of these plants, in the 

 constituents of the stalks, the roots, and the tubers, 

 which the farmer puts upon the arable surface in the 

 form of maniu-e, he restores to the land, in a concen- 

 trated form, the corn constituents for one or several full 

 crops : what was below and scattered, is now above. 

 The clover and the fodder-plants did not engender the 

 conditions of richer corn-crops, any more than rag- 

 gatherers produce the conditions for paper-making : they 

 are mere collectors. 



From the foregoing remarks it is evident that the cul- 

 tivation of plants exhausts the fertile soil, and renders it 

 unfruitfid. Li seUing the produce of his fields, which 

 serves as food for man and beast, the farmer removes a 

 portion of his soil, and indeed the constituents most 



