1 ) J 





THE SOIL OF THE FARM. 



CHAPTER I. 



ORIGIN AND FORMATION OF SOILS. 



Soil and Subsoil — Conversion of Rock into Soil — Processes of Weather- 

 ing and Denudation — Alluvium — Boulder Clay — Vegetable Mould — 

 Peat. 



Soil and Subsoil. — The soil is that part of the ground 

 which can be tilled and in which plants grow. It is 

 merely the upper stratum of decayed rock mixed with 

 A^ege table and animal remains. It varies in depth from 

 less than three inches to more than a foot. 



Immediately below the soil is the subsoil, which rests 

 upon underlying rock. The subsoil is generally more 

 compact than the soil, being less stirred in cultivation; 

 and it is frequently of a different color. The principal 

 difference, however, between the two consists in the greater 

 amount of the organic matter in the latter, which is 

 generally present to some extent in both. 



The main distinction between the soil, the subsoil, and 

 the underlying rock consists in this, that soil is rotted 

 subsoil and subsoil is rotting rock. A vertical section of 

 the soil will generally show several gradations. The 

 whole may be made up of five different layers. There 

 will be: (1) A grass layer; (2) A vegetable soil layer 5 (3) 



(5) 



