CHAPTER IV. 



THE ORIGIN AND COMPOSITION OF SOILS, SHOWING 

 THE NATURAL SOURCES OF THE ELEMENTS AS 

 CONTAINED IN PLANTS. 



AN accurate knowledge of the constituents of 

 soils is equally important to the farmer and planter 

 as a knowledge of the composition of differ- 

 ent crops, and of the materials at his command 

 to produce them. Notwithstanding the im- 

 portance of this knowledge, the chemical com- 

 position of the land is rarely considered in the 

 selection and purchase of a farm ; the fact that 

 it produces crops, the location, convenience to 

 markets, arid the money value of the improve- 

 ments, are the principal considerations. If the 

 land has hitherto produced good crops, it is 

 taken as a guarantee that it will continue to do 

 so ; the soil is not examined, to see how far the 

 stores of organic and mineral matter necessary 

 to fertility have been exhausted. 



It requires but a superficial examination of this 

 subject, to demonstrate that lands should have a 

 commercial value, other things being equal, in pro- 

 portion to the quantity and condition of the valu- 

 able constituents of plants contained in an acre. 



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